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Home My WebLink About2020-03-04 City Council Work Session Meeting PacketAgenda City Council Work Session City of Edina, Minnesota Community Room, City Hall Wednesday, March 4, 2020 5:30 PM I.Call To Order II.Roll Call III.Summary of City Manager Performance Review IV.Review Draft Flood Risk Reduction Strategy V.Adjournment The City of Edina wants all residents to be comfortable being part of the public process. If you need assistance in the way of hearing ampli'cation, an interpreter, large-print documents or something else, please call 952-927-8861 72 hours in advance of the meeting. Date: March 4, 2020 Agenda Item #: III. To:Mayor and City Council Item Type: From:Sharon Allison, City Clerk Item Activity: Subject:Summary of City Manager Performance Review CITY OF EDINA 4801 West 50th Street Edina, MN 55424 www.edinamn.gov ACTION REQUESTED: None. Information only. INTRODUCTION: Mayor Hovland will give a summary of Manager Neal's performance review that took place on Feb. 27. Date: March 4, 2020 Agenda Item #: IV. To:Mayor and City Council Item Type: Reports / Recommendation From:Jessica V. Wilson, Water Resources Coordinator Item Activity: Subject:Review Draft Flood Risk Reduction Strategy Discussion CITY OF EDINA 4801 West 50th Street Edina, MN 55424 www.edinamn.gov ACTION REQUESTED: None; discussion only. INTRODUCTION: Staff and the task force are seeking Council feedback on the draft Flood Risk Reduction Strategy. ATTACHMENTS: Description Staff Report: Review Draft Flood Risk Reduction Strategy Task Force Report: Flood Risk Reduction Strategy DRAFT Flood Risk Reduction Strategy report Appendix F: Actions for Flood Resilient Homes DRAFT fact sheets Appendix H: Potential actions Staff Presentation March 4, 2020 Mayor and City Council Ross Bintner, P.E., Engineering Services Manager Jessica V. Wilson, Water Resources Coordinator Review Draft Flood Risk Reduction Strategy Information / Background: In July 2019 staff began working with a resident task force to develop a Flood Risk Reduction Strategy. The group met over a dozen times, investing hundreds of hours collectively. Through the work, staff and the task force have created a framework and charted a path to reduce the risk of flooding to deliver on this simple strategy; to comprehensively reduce flood risk throughout the community. At the meeting, staff and task force members will present on the framework and strategy. Staff is seeking Council feedback on the draft Flood Risk Reduction Strategy report, provided in the packet. Quick Wins Through the process, we uncovered some ‘quick-win’ actions to implement immediately. • Actions for Flood Resilient Homes Fact Sheets. These two-page fact sheets describe common actions that people can take to reduce their own exposure and vulnerability to flooding. A sample of the draft fact sheets are provided in the packet. The complete set of fact sheets is expected to be finalized within the month. • “What is my flood risk?” interactive map. This application allows users to visualize the flooding on the land surface for any property in the City of Edina. This information is already available on the interactive water resources map; however, this application is more focused on communicating flood risk specifically. Once finalized, the map will be available on the Maps page of the City website. The application can be previewed at a temporary weblink at; https://barrgisonline.maps.arcgis.com/apps/webappviewer/index.html?id=79c2a16b53af475dbc284cd2 df9e4fee • Sandbagging how-to videos. The City provides sandbags, free of charge. This series of videos will be used to promote the service, inform people on how to request sandbags, demonstrate how to build STAFF REPORT Page 2 a sandbag dike, and describe how to dispose of sandbags after a flood. Video production is anticipated to occur this spring. Next Steps Staff will finalize the Flood Risk Reduction Strategy based on Council and task force feedback from the work session and propose to bring the finalized report to the April 7th City Council meeting for final approval. Staff will prepare a scope of service for preliminary engineering for stormwater infrastructure related to the roadway reconstruction projects in the Morningside C, D and E maintenance groups scheduled for reconstruction in 2022 and 2023. Staff will also ask Council to consider the engagement plan to go along with the project design. This would be the first major roadway reconstruction project to be designed under the proposed Flood Risk Reduction Strategy. Staff will prepare a scope of service to complete a major amendment to the Comprehensive Water Resources Management Plan in order to incorporate the Flood Risk Reduction Strategy into the policies and implementation actions of that Plan. Summary of proposed next steps; 1. Council considers approval of Flood Risk Reduction Strategy. 2. Council considers approval of preliminary engineering scope of service for the Morningside D/E and Morningside C neighborhood roadway reconstruction projects in 2022 and 2023, respectively. 3. Council considers approval of Morningside Neighborhood roadway reconstruction design engagement plan. 4. Council considers approval of scope of service for major amendment to Comprehensive Water Resources Management Plan. Task Force Acknowledgement Staff would like to thank the Task Force for their contributions. The experience, knowledge, and curiosity they brought to the process added value and influenced the framework and strategy. Nora Davis (co-chair), Lake Cornelia Neighborhood Kathy Amlaw (co-chair), Lake Edina Neighborhood Greg Lincoln, Morningside Neighborhood Michael Platteter, Morningside Neighborhood Louise Segreto, Indian Hills Neighborhood Roxane Lehmann, Sunny Slope Neighborhood Richard Strong, Concord Neighborhood Richard Manser, Todd Park Neighborhood The Task Force has provided their own report, included in the packet. Flood Risk Reduction Task Force - 2020 City Council Report “For decades Edina took land from the water – now the water wants the land back” Task Force Work The Flood Risk Reduction Task Force began meeting in July of 2019. For the past several months the Task Force has grappled with this increasingly complex issue. There are no simple answers. Flooding issues will require a multi-pronged approach across multiple sectors within the community. Many of the actions we are suggesting have environmental benefits – which will assist Edina in achieving Climate Action Plan goals. BACKGROUND Edina History Settlers first arrived in Edina in the 1800’s and by the end of 1854 all the land in Edina had been claimed. Much of the western portion was part of the “Big Woods” – with elm, basswood, maple and oak trees. The terrain was uneven and much of the area was poorly drained and swampy. Over time many of the hills were bulldozed, trees felled, the wetlands filled in – and development began. Two hundred years of development has profoundly affected storm water management, and this is a major factor in our current flooding problems. Scope of problem In preparation for the 2018 Comprehensive Water Resource Management Plan, Edina staff and consultants reviewed the city for areas of flooding concern... Five areas in the city were chosen for further study – Weber Park, Concord, Halifax, Southdale First Addition Residential & Crosstown 62 & Hwy 100. Another twenty areas were screened, while fifty-four areas await further study. In total – those areas contain - 692 homes/apartment buildings, and 863 structures. Storm water affects Edina in a variety of ways – including overflow from natural bodies of water to runoff from developed areas causing street flooding, damage to basements from seepage and ground water to sanitary sewer system back-ups. This is a situation affecting the health and safety of residents and those who visit, shop, and work in our community. Each news cycle brings yet more warnings about the damage of increasing rainfall and ground water issues – and Edina is not immune. Contributing Factors Increased rainfall due to Climate Change – in 2019 we received 43.17 inches of rain, 12.56 inches above average. Rains will continue to increase, and those rains will come fast, hard and more frequently. Early snow melt compounds the flooding problem, causing additional problems for residents. Ground water levels are rising and are difficult to measure. More residents are operating sump pumps year-round – while other residents are discovering they now need to install a sump pump. More development replaces vegetation and soil with impervious surfaces. Impervious surfaces causes rainwater to runoff rather than infiltrate natural ground surface. Not only does runoff cause surface water to accumulate in land depressions, it can cause rainwater to reach streams faster and in greater quantities; both increasing the risk that flooding will occur sooner and more severely than if rain were to fall on the natural ground surface. Impervious surfaces also increase the “heat island effect” causing yet more rain. The issue is not going away – and it’s imperative that Edina approach this situation proactively. Reduced imperviousness results in less runoff. Any reduction in the amount of runoff translates into increased infiltration and enhanced flood control. Limiting impervious surfaces and increasing the City’s greenspace will help reduce runoff volume, lower summertime temperatures, and improve both water and air quality. Increased greenspace will also make our community more attractive and promote recreational activities that enhance the quality of life for those who live, shop, visit and work in Edina. Our Recommendations Land Use • Regulate impervious surfaces to promote green space, trees and filtration. (Impervious surfaces have increased by 80% in Morningside over the past 50 years – exposing that neighborhood to serious flood risk.) • As property is redeveloped add below ground water storage and above ground storage. Above ground storage (day-lighting the water) adds environmental benefits in addition to water storage. It also serves as a “water feature” for the development. • Restrict removal of mature trees. Encourage tree planting and rain gardens • Increase green space/park areas for both temporary water storage and environmental benefits • Voluntary buy-out of homes and converting that land to temporary storage/park /green space. Allowing a rebuild at higher elevation does nothing to protect the neighborhood. Infrastructure • Be proactive (rather than reactive) in maintenance of current system • Improve data collection to assist in planning, protection and outreach efforts • Replace aging infrastructure • At street reconstruction add larger storm sewer pipes, lower streets for temporary storage • Pumping if cost effective and doesn’t create issues for others Education • Provide education to residents on a number of platforms to alert them to their flooding risks and how to mitigate those risks. This effort would include information on city services including sandbag delivery, placement and pick-up, along with information on flood insurance. • Reach-out to plumbing contractors and other water mitigation businesses to inform them of Edina’s permitting and regulations regarding water issues. • Continue the Technical Support Program through Edina’s Engineering Department to help residents reduce their risk Ongoing • Develop a comprehensive Emergency Plan to assist residents during and after a flooding emergency. Plan should include volunteers who could assist homeowners with sandbagging and flood clean-up. (Service clubs such as the Edina Rotary clubs, faith communities, etc.) • Continue to work with both watershed districts and surrounding communities to address ongoing water issues. Respectfully submitted: Flood Risk Reduction Task Force Members Richard Strong, Louise Segreto, Michael Platteter, Richard Manser, Greg Lincoln, Roxane Lehmann, Nora Davis (Co-chair), Cathy Amlaw (Co-chair) CITY OF EDINA FLOOD RISK REDUCTION STRATEGY March 4, 2020 – City Council Work Session Draft City of Edina, Engineering Department www.EdinaMN.gov 1 Table of Contents Executive Summary ....................................................................................................................................... 3 Problem statement ....................................................................................................................................... 5 Project initiation ....................................................................................................................................... 5 How flooding occurs ................................................................................................................................. 6 Groundwater levels are increasing: summary of monitoring data ....................................................... 8 What is flood risk? .................................................................................................................................... 8 Drivers of increasing flood risk ................................................................................................................. 9 Getting to scale: a challenging problem made even more challenging, climate change impact analysis ................................................................................................................................................ 11 Climate Action Plan: in progress item ................................................................................................. 11 Formulating a Strategy ................................................................................................................................ 12 Comprehensively Reduce Flood Risk throughout the Community ......................................................... 12 The gap between the current Comprehensive Water Resources Management Plan and the Strategy 13 City Sectors of Work and Service ................................................................................................................ 14 Infrastructure .......................................................................................................................................... 14 Go Big, Go Bigger: infrastructure analysis .......................................................................................... 15 Morningside Roadway Reconstruction Engineering Study: in progress item ..................................... 16 Regulation ............................................................................................................................................... 18 Keep your water to yourself: private infrastructure analysis ............................................................. 20 From ‘ill-drained’ to impervious: impervious surface analysis ........................................................... 21 Impervious limit: in progress item ...................................................................................................... 22 Outreach and Engagement ..................................................................................................................... 22 Outreach products: in progress item .................................................................................................. 23 Emergency Services ................................................................................................................................ 23 Strategy Development ................................................................................................................................ 24 Task Force role and process .................................................................................................................... 24 Brainstorming, prioritizing, and categorizing possible actions ............................................................... 26 Conclusion ................................................................................................................................................... 26 Next steps ................................................................................................................................................... 27 Acknowledgement ...................................................................................................................................... 28 Appendix ..................................................................................................................................................... 29 2 Appendix A: ‘Groundwater levels are increasing: summary of monitoring data’, technical memo ...... 29 Appendix B: ‘Getting to scale: a challenging problem made even more challenging, climate change impact analysis’, technical memo ........................................................................................................... 29 Appendix C: ‘Go Big, Go Bigger: infrastructure analysis’, technical memo ............................................ 29 Appendix D: ‘Keep your water to yourself: private infrastructure analysis’, technical memo ............... 29 Appendix E: ‘From ‘ill-drained’ to impervious: impervious surface analysis’, technical memo ............. 29 Appendix F: Actions for Flood Resilient Homes, fact sheets .................................................................. 29 Appendix G: Task Force charge ............................................................................................................... 29 Appendix H: Potential action matrix key, ranked response, and potential action matrix ...................... 29 3 Executive Summary This draft of the flood risk reduction strategy summarizes a ten-month task force effort where staff and community members worked to come to a shared understanding of what flooding is, and how we can connect on the promise to comprehensively reduce the risk of flooding throughout the community. We expanded and developed our understanding of how we view flood risk, to include; • The key equation; = × × o Flooding starts with the weather and climate, requiring an awareness of short- and long- term risks. Rainfall varies over time, and climate change increases the extremes. o Flood exposure depends of landform, runoff, flow, drainage, and groundwater. These factors vary spatially, some areas having higher exposure to flood waters or flow. o Flood vulnerability depends on the assets, public and private, that are on the land and exposed to flooding. Increasing climate extremes drive flood exposure and demands adaptation or resilience increase commensurately to keep risk constant. • Pathways for structural risk; o Over the land surface; Intense storms can cause high water in both local and regional low areas, and overland flow paths o Groundwater seepage; Long term wet periods can raise groundwater putting stress on building foundations, and flood low-lying landlocked areas o Sanitary backflow; Flooding in nearby structures can overwhelm the sanitary system and cause backups • Risk reduction efforts depend on the time o The best time to reduce flood vulnerability is before the flood o During a flood focus shifts to staying safe from harm, or sustaining or restoring services o After the flood, we focus on recovering and reviewing risk We explored the community aspects of flooding, and the City’s role. • Problem; We will make flood information available to all and promote flood awareness • People; We will work to help people stay safe in floods • Property; We will help people protect their properties from flooding and the effects of floods • Places; We will plan public streets and parks to accept and transmit flood waters to reduce risk and disruption of related city services We reviewed City areas of work, and the relationships to flood risk. • Infrastructure: We will renew our infrastructure and operate it to reduce risk • Regulation: We acknowledge competing demands of land use, solving drainage, groundwater, and surface water issues. We help people solve issues without harming another. • Outreach and Engagement: We make flood information available and give people tools for flood resilience. • Emergency Services: We help people prepare for floods, remove people from harm during floods, and help people recover after floods. 4 We reviewed key drivers of increasing risk and areas of work to inform questions about the pace of implementation and possible next step actions; • Climate; Climate change is making storms more intense and increasing the chance of extended wet periods or drought. This is the overwhelming driver increasing future flood exposure. • Aging and obsolete infrastructure; Our pipes are old and not up to the current demands. This is a significant driver as infrastructure provides most stormwater service. • Demand for well drained landscapes; Development has connected the landscape to the water to make land well drained. While this a major historic driver, it is a minor driver increasing future flood exposure. Most of the drainage and land development decisions have been made, but there are some public and private system retrofits that continue to connect landscape and water bodies, marginally affecting flood exposure. • Imperviousness; Community demand for garages, parking areas, patios, decks, pools, and bigger homes has increased the hard cover of soils. This is a minor driver increasing future flood exposure. Most of the land development decision have been made, but small additions to impervious cover marginally affect flood exposure. Soils can’t soak up the amounts of water floods provide. We reviewed possible actions, evaluating effectiveness, value, and community support to map out future planning. A few quick-win items were started where existing resources allowed and are presented as appendix to this report. Other items were classified as planning or development items that imagine a future level of implementation with expanded skill and resources. These efforts to put flooding into focus have resulted in the creation this framework and draft strategy for Council and task force review, to connect on the promise to comprehensively reduce the risk of flooding throughout the community. 5 Problem statement Flooding can affect people, damage property, threaten health and safety, and disrupt transportation and business. Flooding is common in Edina and climate change is expected to make flooding worse. Flooding has historically been considered a technical problem, requiring a technical solution. Land ownership, space, legislation, and hydrology are interwoven with values about problem ownership, water stewardship, service tradeoffs, and transferring risk. What was once considered purely a technical problem may be more of a mix of a technical, scientific, political, and social one. This type of problem requires a different set of strategies, skill sets, and tools. Timothy M. Gieseke. Shared Governance for Sustainable Working Landscapes Project initiation In September 2018 City Council adopted the 2018 Comprehensive Water Resources Management Plan. The implementation section of the plan included development of a Flood Risk Reduction Strategy. A City Manager Task Force of Edina residents was formed to provide a community voice to the process. The City recognizes the contribution of these individuals and appreciates the value they’ve provided. Task Force members; Nora Davis (co-chair), Lake Cornelia Neighborhood Kathy Amlaw (co-chair), Lake Edina Neighborhood Greg Lincoln, Morningside Neighborhood Michael Platteter, Morningside Neighborhood Louise Segreto, Indian Hills Neighborhood Roxane Lehmann, Sunny Slope Neighborhood Richard Strong, Concord Neighborhood Richard Manser, Todd Park Neighborhood The Task Force was charged with supporting and providing recommendations to inform the development of this strategy, specifically to; • Incorporate local challenges, opportunities, knowledge, and community values • Incorporate voices from throughout the City of Edina. While the Morningside neighborhood has been identified as a focal geography for case study, strategies and outcomes ought to be scalable city-wide. 6 • Identify action steps for building community capacity to address flood risk and resiliency in Edina. In July 2019 staff began working with a resident Task Force to develop a Flood Risk Reduction Strategy. The group met over a dozen times, investing hundreds of hours collectively. The strategy doesn’t solve flooding. We’ve learned that it’s too big of a problem to solve outright; however, we’ve charted a path to reduce the risk of flooding. Through this effort, we; • Explored technical questions like, “How much does impervious cover matter?”, “What kind of flood risk does the future hold in the wake of a changing climate?”, “How much benefit can private storage provide?”, and “How much benefit can bigger infrastructure provide?” • Interviewed the operators and maintainers of the system to better understand the level of service the system currently provides and its vulnerabilities. • Gained a better understanding of the factors and drivers that influence flood risk. • Described the various ways in which structural flooding occurs; over the land surface, through groundwater seepage, and sanitary sewer backflow. • Defined the areas within which we already work and identified other actions the City could undertake, connecting these areas of work to Council work plan goals. • Widened our approaches for reducing flood risk. • Heard people share their experience and knowledge about flooding. The Task Force shared their community values around flood risk and informed the framework and strategy. Based on Council and community feedback, the Morningside neighborhood was selected as the focal geography for the Flood Risk Reduction Strategy. Further description about how the neighborhood was used to test ideas is provided in the Strategy Development section of this report. Throughout this report, we briefly highlight relevant in-progress items and summaries of the technical analyses – more detailed memorandums describing the technical analyses are provided in the Appendix. How flooding occurs Too much water from rain or melting snow can overwhelm the system. Pipes run full, intersections flood, lakes and creeks overtop their banks, water flows over the land surface, sidewalks and paths become impassible, yards are inundated, groundwater builds up, water seeps through basement walls and floors, and water can back up into homes through sanitary sewers. 7 8 Groundwater levels are increasing: summary of monitoring data Groundwater levels are increasing: summary of monitoring data In the winter of 2020 Nine Mile Creek Watershed District and Minnehaha Creek Watershed District separately convened local water resources and emergency managers to share their groundwater level monitoring data. After a string of exceptionally wet years and a record-breaking precipitation year in 2019, lakes and creeks are high, the ground is saturated and, in many places, groundwater level monitoring records show water table elevations are on the rise. One groundwater monitoring well in Edina near Bredesen Park shows an increase of about 15 feet since 2010. In areas where the depth to the regional groundwater table is shallow, structures with basements are at an increased risk for flooding from groundwater seepage. Groundwater is difficult to map. It’s dynamic, inconsistent, and the distribution can vary drastically from what we see on the land surface. More information about local groundwater level monitoring data is available in the appendix. What is flood risk? Flood Risk: Flood risk is determined by climate, exposure, and vulnerability. Flood Exposure: The degree to which property, homes, buildings, infrastructure, and other assets come into contact with flood water. Flood Vulnerability: The degree to which exposed assets are unable to resist flooding and are damaged by floods. For example, two homes side-by-side might have the same flood exposure, but one home might be less vulnerable to the exposure. Vulnerability can be decreased with the installation of downspouts, proper grading, a basement sump pump, waterproof or reinforced foundations, mature trees with strong root systems, and excellent drainage through well-designed rain gardens, among other things. 9 Flood risk factors and definitions adapted from IPCC, 2012: Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation. A Special Report of Working Groups I and II of the Intergovernmental Panel on Climate Change. Drivers of increasing flood risk Flooding issues within the City of Edina continue to increase in frequency and severity. The following have been identified as primary drivers leading to increased flood risk. Climate change and changing weather patterns: • Climate change is the lead driver of increasing flood risk in Edina. Climatologists indicate that large, intense rainfall events are occurring more frequently, and models predict that large rainfall events will become more intense in the future. Minnesota is already experiencing prolonged wet periods; in fact, the years between 2015 and 2019 were the wettest in Minnesota history and we can expect more wet years in the future. This increase is also impacting neighboring communities, is occurring at the international, national, state, and watershed levels, and is expected to get much worse. • With the update to the Comprehensive Water Resources Management Plan, the most recent precipitation frequency estimates were incorporated into the City’s flood model which showed increased flood risk throughout the City. It should be noted that this data only brings us to current climate conditions and does not provide protection for additional future risk caused by climate change. • Modeling of storms and flood risk, and visualization of that risk has improved dramatically in recent decades, leading to better community perception of risk. • See ‘Getting to scale: a challenging problem made even more challenging, climate change impact analysis’ and ‘Climate Action Plan: in progress item’ sections of this report. Aging and obsolete infrastructure: • Infrastructure is aging, and much is in poor repair, stretching maintenance and operations staff thin. Current resources dictate a reactive approach instead of a proactive approach. • The current stormwater system was built for a different time and standard. Climate change has already increased the risk and made most of the system obsolete. 10 • Needs far exceed available resources. Flooding issues are extensive and improvements that address the 1%-annual-chance storm are often out of reach at current levels of funding. Demand for well-drained landscapes: • Development has connected the landscape to the water to make land well drained. Demand for well-drained landscapes has led to private and public drain line and gutter expansion. This expansion directly connects the landscape and the water generated there to downstream properties and waterbodies. • While this a major historic driver, it is a minor driver increasing future flood exposure. Most of the drainage and land development decisions have been made, but there are some public and private system retrofits that continue to connect landscape and water bodies, marginally affecting flood exposure. Imperviousness: • Community demand for garages, parking areas, patios, decks, pools, and bigger homes has increased the hard cover of soils. • There is an increasing trend of imperviousness in the City of Edina. Specifically, within the focal area of Morningside, nearly one million square feet of impervious surfaces (homes, structures, driveways, patios, swimming pools, etc.) have been added since 1950. This equates to about 14% of the total size of occupied parcels in the Morningside neighborhood (2019, City of Edina staff). • This is a minor driver increasing future flood exposure. Most of the land development decision have been made, but small additions to impervious cover marginally affect flood exposure. Soils can’t soak up the amounts of water floods provide. • See ‘Keep your water to yourself: private infrastructure analysis’, ‘From ‘ill-drained’ to impervious: impervious surface analysis’, and ‘Impervious limit: in progress item’ sections of this report. 11 Getting to scale: a challenging problem made even more challenging, climate change impact analysis Getting to scale: a challenging problem made even more challenging, climate change impact analysis Through the Task Force process, staff heard the sentiment, “stop studying the problem, you have the answer, it’s time to act.” While action is needed now, this report rebuts the sentiment that we have the answers. Our new understanding of risk in the 2018 Comprehensive Water Resources Management Plan show the system is overloaded. We now can more easily see how ‘solving’ a problem in one area can make a downstream problem worse. ‘Solutions’ need to review downstream risk and be packaged together comprehensively, acknowledging or mitigating the risk transfer. Packaging problems requires a scale of effort that has not been attempted in Edina, and the scales contemplated still do not totally ‘solve’ the problem, instead they may not even be keeping up with climate change. Climate change is changing the target. Solutions of today have to accommodate more water than in the past, and solutions have to withstand the effects of climate change in the future. We need a new approach to planning. It is necessary to shift the approach from trying to reduce flood exposure for some, to reducing the vulnerability to flooding for all. A memorandum describing the analysis in more detail is available in the appendix. Climate Action Plan: in progress item Climate Action Plan: in progress item Development of a Climate Action Plan would further outline and prioritize actions for climate change mitigation and adaptation. City staff is working to scope a process for creating a Climate Action Plan for Edina. The Energy and Environment Commission recently completed a study and report on a timeline and parameters for such a plan, including the City’s leadership role. Undoubtedly, carbon reduction in both the private and public sectors will be an area of opportunity. In order to meet community-wide emission reduction goals, it will take a process that includes the community to understand what actions are important and how to prioritize them. There is a clear overlap between addressing flood risk and mitigating climate change. To that end, it is prudent that the Flood Risk Reduction Strategy inform the larger Climate Action Plan work of the City’s Sustainability Manager and Energy and Environment Commission. 12 Formulating a Strategy Comprehensively Reduce Flood Risk throughout the Community Flooding in Edina is not only common, it’s increasing. The City of Edina’s strategy is to comprehensively reduce risk throughout the community. This means we address flooding through a broad range of actions and that decisions consider the assets and people that characterize the City. Approaches for managing risk include reducing exposure, reducing vulnerability, transferring and sharing risks, increasing resilience to changing risks, and preparing, responding and recovering from floods. Adapted from IPCC, 2012: Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation. A Special Report of Working Groups I and II of the Intergovernmental Panel on Climate Change Strategy helps answer the question, “What are we trying to accomplish?” Every community has limited resources and deals with its own unique challenges – strategy acts as a guide to a set of actions and filters out those that do not fit. Tactics help answer the question, “How are we going to accomplish our goal?” Tactics are the actions within the following City sectors of work; infrastructure, regulation, outreach and engagement, and emergency services. Each sector of work supports a City Council work plan goal. Flood Risk Reduction Approaches Reduce Exposure Reduce Vulnerability Transfer and Share Risks Increase Resilience to Changing Risks Prepare, Respond, and Recover 13 These areas of work and the current state of practice are spelled out in greater detail in the water resources chapter of the Comprehensive Plan and the Comprehensive Water Resources Management Plan. The gap between the current Comprehensive Water Resources Management Plan and the Strategy Past iterations and the current Comprehensive Water Resources Management Plan have focused primarily on reducing exposure to flooding or transferring risk, although sometimes in unknown or unexpected ways. This often means capital infrastructure projects to modify the flood or regulatory standards applied when properties develop or redevelop. The current Comprehensive Water Resources Management Plan outlines projects that add or upsize pipes or surface flood storage. This narrow approach has some pitfalls. • First, it limits the approaches, and thereby the actions that could be implemented to reduce flood risk. The actions focus on reducing exposure only. Many opportunities exist using 14 approaches to reduce vulnerability, transfer and share risks, increase resiliency to changing risks, and preparing, or responding, and recovering from flooding. • Second, it ignores the risk transferred to downstream people and assets. Many of the capital infrastructure projects don’t consider impacts outside the immediate project area. In a fully developed landscape, many of the downstream storage areas in Edina and in our neighboring communities are already full. • Third, it implies that the public realm is the only opportunity space to reduce risk – some of the simplest and most cost-effective ways to reduce risk are for people to reduce the vulnerability of their structures and property. Some resources to this end have been developed as part of this process (see Outreach Products in the Outreach and Education section of this report). • Fourth, it doesn’t recognize the lead driver; climate change, and sets us on a path in which we cannot catch up to the increasing risk. The strategy and associated actions must be able to scale to the problem. City Sectors of Work and Service The City of Edina works in the following four sectors to reduce community flood risk. Detailed in each sector overview is; a statement of the intended outcome of the work, a list of the City departments and partners who lead the work, a list of City departments and partners who help, are involved, or are part of the process, a description of when and how flood risk is considered, and a summary of gaps identified during detailed discussions with the Task Force. Infrastructure What is the outcome; Building stormwater infrastructure that manages areas of flood flow and storage that with the landscape, define areas of vulnerability. Reducing the vulnerability of infrastructure so they are durable to extreme events or fail safe. Reducing exposure and vulnerability of related sanitary sewer infrastructure that can serve as a conduit for flood waters between structures. The service provided by water resource and other infrastructure is defined in the 2018 City of Edina Comprehensive Plan and Comprehensive Water Resources Management Plan. Who does the work; Public Works Department, Engineering Department, property owners, private redevelopment, and contractors. Who is involved; Planning Department, Building Department, and future property owners. When flooding risk is considered; At decision points, in projects, design, failure analysis, during infrastructure planning. Gaps; Actual service level falls short of expected service, aging infrastructure, reactive maintenance, reactive emergency response, capital improvements do not have scale to ‘fix it’ or even keep up with climate change trend. Pace of redevelopment: Currently driven by owners of at-risk properties. The City could establish a program including eligibility and standards for purchasing, redeveloping to a flood-resilient standard, and selling properties. 15 Enhancing public infrastructure by building new, retrofitting old, and keeping what we have in working condition is a key action to reducing flood exposure. Stormwater systems route water to low areas where it is temporarily stored, and then they work to convey water downstream. The stormwater system is made up of 127 miles of gravity main ranging from 12-84” in diameter, 6800 manholes, 900 outlets, 38 miles of small diameter sump drain, 11 stormwater lift stations, one half mile of stormwater force main, and 150 ponds and wetlands (2018 Draft Comprehensive Plan Chapter 7). The City’s stormwater system was designed to convey a certain amount of water and protect against impacts at a certain level. This “level of protection” is based on the capacity of public infrastructure to handle stormwater and on the likelihood, or probability, that a storm will occur. When storms are bigger or more intense than the infrastructure is designed to handle, or when it clogs, there are consequences such as disruptions to services, facilities, or damage to property. The city stormwater system is exposed to flooding and also determines the flood exposure of people and assets. Risk is changing primarily because climate is changing and the level of protection for design is a moving target. Designs from the past are undersized for today and there is a growing realization in technical circles that even if designs were revised to reflect today’s climate they would quickly be obsolete due to the changing risk brought by climate change. Go Big, Go Bigger: infrastructure analysis Go Big, Go Bigger: infrastructure analysis To test the possible scale of implementation in the face of projected climate change impacts, a preliminary evaluation and conceptual design of potential flood risk reduction options for the Morningside neighborhood was completed. A cursory evaluation was conducted to assess which option reduced flood exposure for the most homes. This was completed for a range of storm events from the 20%-annual-chance storm event (5- year storm which is 3.6 inches in 24 hours) to the 1%-annual-chance storm event (100-year storm which is 7.5 inches in 24 hours). Infrastructure options that were evaluated included increasing storm sewer pipe sizes, constructing flood walls, creating additional flood storage by excavating (lowering) the ballfield area of Weber Park and then reconstructing the fields, creating additional flood storage by excavating the wooded area north of Weber Pond and excavating and re-grading existing low areas (e.g. low area at Lynn Avenue and Kipling Avenue north of West 42nd Street), excavating backyards in key locations, installing predictive pumping systems for a few key areas (including Weber Pond), and installing underground flood storage. Seven infrastructure options were developed using combinations of some of the mitigation options identified above with planning-level costs estimated between $3.4M and $31.6M. The option with the largest benefit in terms of homes that would no longer be exposed to flooding up to the 1%-annual- chance storm event (Option 7b, the ‘Go Bigger’ option) has an estimated cost of $8.5M and 16 completely removes approximately 24% of the homes potentially impacted under existing conditions. The next best infrastructure option (Option 2b, the ‘Go Big’ option) removes approximately 16% of the homes currently impacted and would cost approximately $4.5M. Baseline; the current replacement value of stormwater infrastructure in the City is about $70M. Over 16 square miles this is approximately; • $6,800/acre • Baseline replacement value of stormwater infrastructure The ‘Go Big’ option contemplated a $4.5M project serving about 630 properties and 185 acres. • $24,300/acre • Cost 3.6 times larger than the baseline The ‘Go Bigger’ option contemplated an $8.5M project serving about 630 properties and 185 acres. • $45,900/acre • Cost 6.7 times larger than the baseline In addition to costs, the projects come with tradeoffs, contemplating major changes in parks, open spaces, existing water bodies, and piping and utility operations changes. The projects also present opportunity for co-planning around park and sustainability improvements as sections of aging infrastructure are renewed. A memorandum describing the analysis in more detail is available in the appendix. Morningside Roadway Reconstruction Engineering Study: in progress item Morningside Roadway Reconstruction Engineering Study: in progress item Infrastructure options remain the foundation of reducing flood exposure, but the scale of climate change will make transformation change a challenge. In April 2020 staff will ask Council to consider a scope of service for preliminary engineering for the street reconstruction project in the Morningside D/E and Morningside C neighborhoods in 2022 and 2023, respectively. Staff will also ask Council to consider the engagement plan to go along with the project design. This would be the first major street reconstruction project to be designed under the proposed flood risk reduction strategy. The operations and maintenance of public infrastructure is a key component of reducing flood risk. Operations includes inspection and condition assessment, street cleaning, catch basin clog clearing, pipe and outlet clog clearing, sediment control, pump and power system monitoring, and emergency 17 operations. Maintenance includes catch basin repair, pipe repair, outlet repair, sediment removal, weed and woody debris removal, and other actions. Stormwater models that predict flood problems assume that all pipes, catch basins, inlets, and outlets are in good working order and free from obstructions. The reality is that material and debris often enter the system before or during storms and can cause service disruptions. Aging infrastructure also lends to more failures. Staff prioritizes their stormwater operation and maintenance work based on opportunity and requests for service within the constraints of their resources. Opportunities include repairing and renewing stormwater infrastructure in areas where other work is already planned. For example, crews inspect and repair stormwater catch basins in neighborhoods where street improvements are planned, thereby extending the life of the street improvement and providing real value to the public. Requests for service also get prioritized. As storm events occur, staff evaluate the risk and respond as resources allow. Operations and maintenance staff were invited to talk about their work with the Task Force. Some themes related to the challenges and opportunities emerged. Challenges related to operation and maintenance: • Much of the system aside from pump and power systems are managed with reactive, run-to-failure approach and there is significant deferred maintenance in the system leading to small items remaining unaddressed, leading to larger issues. • The program for evaluating maintenance needs meets the minimum regulatory standard. It is not comprehensive. • The system is aging, much of it originating in the 1950s and 1960s. • During events, stormwater systems and sanitary sewer systems are stressed at the same time. When flood events coincide with snow and ice events, staff are further stretched to provide services and must make decisions about priorities, constrained by their resources. • Some stormwater features in the city have been installed to intentionally capture pollutants and debris in order to protect clean water. When not properly maintained, they can interfere with overlapping drainage and flood protection services. • Service levels are not clearly defined. During the peak of events, staff are receiving, prioritizing, responding to, and communicating on requests for service. Residents often don’t know where their issue ranks or what service level they can expect. Opportunities for operation and maintenance: • Proactive maintenance, the benefits of which go beyond flood protection. Proactively cleaning and maintaining stormwater infrastructure can support clean water goals by properly managing accumulated pollutants. • Increased street sweeping to keep stormwater conveyances clear. This also has a clean water benefit. 18 • Promotion of the new metro-wide adopt-a-drain program to augment city street sweeping. Residents are asked to adopt a storm drain in their neighborhood and keep it clear of leaves, trash, and other debris to reduce water pollution. The program also works to provide flood protection. Often, once a system is flooded, the primary objective for maintenance staff is to clear the obstruction. At this point, the opportunity to clear and dispose of clogging debris before its transported to downstream waterbodies is largely lost. • High value infrastructure retrofits. In some cases, maintaining and optimizing existing can be more cost effective than new infrastructure. • Better definition of service levels residents can expect for given issues. • More general communication about the City’s flood response during and after events. • Continued investment in the sanitary sewer system and its resiliency during floods. An increase in resources dedicated to public works staff would be required in order to address issues and capitalize on opportunities in operations and maintenance. Regulation What is the outcome; Homes and buildings have reduced exposure to floods. Those that are exposed to floods take actions to reduce vulnerability. Private improvements such as structures, landscaping, grading and other private systems manage their own risk, and take actions that do not increase exposure of neighboring properties, reducing it if possible. Who does the work; Engineering Department, Building Department, private permit applicants. Who is involved; Public Works Department, Planning Department, future property owners. When flooding risk is considered; At application and permit, during construction, at final inspection and permit close. Gaps; Added impervious marginally increases community risk, long term maintenance of private drainage systems is uncertain, “retail” nature of permitting a variety of single family improvements is time intensive, regulation in limited areas due to limited resources, the first point of contact that interfaces with builders, homeowners, and describes issues in homes with existing exposure is time intensive. Redevelopment provides a once in a generation opportunity to build-in resilience. City staff are actively engaged with the development community through regulatory programs and provide technical support to permitted and affected private parties. In response, new structures or additions can be required to meet minimum elevations for low floors (such as basements) or low openings (such as windows wells). Another response to redevelopment includes requiring durable flow paths to route water away from structures. The City could consider enhancing standards for resilience in redevelopment plans or encourage a deeper risk conversation with the development community to promote resilient decision- making within the permit process. Increased regulation of redevelopment in Edina would reduce risk. A 19 tradeoff would be that a change in regulation could impose additional costs to developers and impact overall market conditions. Future flooding is projected to get worse. The models that predict flood risk use data from the past to estimate precipitation. The City could consider a flood risk standard that incorporates future risk due to climate change to match the lifecycle of the private improvements that rely on them. By planning street flood storage, lowering roads, managing overflow paths, and taking other actions based on a future flood risk level due to climate change, capacity could be built into the system to make them future ready for their expected design lives. Land use is often cited as a key sector for managing flood risk, though fully developed communities such as Edina may not be able to realize the same returns in this sector as a less developed community. Many of the decisions about land use in Edina have already been made – that is to say that neighborhoods emerged in places and at times that might not have otherwise happened if those land use decisions were made today. The regulatory program remains an effective way to reduce the consequences of flooding for the developing property. The City could consider further enhancing the outreach to property owners, builders and developers to promote resilient design. Where they work: As private improvements are made, or properties redevelop, the City provides flood risk information and holds standards that control or mitigate the exposure to flooding through its regulatory program. Existing controls through the regulatory program are working to raise the low elevations or low opening of structures. This raising of structures reduces the exposure to flooding. Where they don’t work: While the regulatory program is good to reduce exposure and vulnerability to the property or improvement that is changing and its immediately adjacent neighbors, it is a poor tool to reduce the flood exposure downstream. 20 Keep your water to yourself: private infrastructure analysis Keep your water to yourself: private infrastructure analysis The impact of comprehensive stormwater storage including underground storage within private property, the right of way, or under streets in the Morningside neighborhood was evaluated. This analysis was conducted as a result of Task Force discussions about the potential impacts of requiring private homeowners to store stormwater running off from their impervious areas on-site similar to requirements for commercial development. The benefits achieved by storing the first 1-inch, 2-inches, and 3-inches of precipitation from storm events of varying size, from the 20%-annual-chance storm event (5-year storm) to the 1%-annual- chance storm event (100-year storm) are summarized in the table below. For the private storage evaluation underground storage vaults were assumed under a portion of each of the 570 residential parcels within the Morningside neighborhood. The analysis showed that storing the first 1-inch of storms of this magnitude had a negligible impact on flood levels. Storing the first 2-inches and 3-inches showed a more significant benefit with regards to reduction in peak flood levels. Depending on the storm event, and depending on the location within in the neighborhood, the results varied anywhere from flood level decreases of a few inches to decreasing nearly a foot and a half. However, this apparent benefit comes at an initial cost of approximately $15,000 per inch of stormwater stored per residential parcel. To store 2-inches of runoff in the entire neighborhood would cost approximately $17 million. In addition, while the flood levels may be lowered, the number of homes that are removed from potential impacts from flood inundation is small. For example, one home may potentially be removed from flood inundation at Weber Pond depending on the storm event. Finally, the management and maintenance of these underground stormwater storage vaults distributed throughout an entire neighborhood is expected to be complicated and unprecedented. This solution would provide a moderate benefit for a very high cost. Additionally, a preliminary look at the compounding effect of climate change suggests that any improvement realized by implementing additional storage would be taken back by climate change (i.e., increased precipitation amounts). Inches of Runoff Stored on Private Property Approximate Cost for All Parcels in Morningside to Store Runoff Flood Level Reduction Benefit (in feet) for Weber Pond Subwatershed (MS_40) 5-yr Storm (3.6" of precipitation) 10-yr Storm (4.3" of precipitation) 50-yr Storm (6.4" of precipitation) 100-yr Storm (7.5" of precipitation) 1 inch $ 8,550,000 0.1 <0.1 <0.1 0 2 inches $ 17,100,000 0.6 0.3 0.5 0.3 3 inches $ 25,650,000 0.7 0.9 0.6 0.5 A memorandum describing the analysis in more detail is available in the appendix. 21 From ‘ill-drained’ to impervious: impervious surface analysis From ‘ill-drained’ to impervious: impervious surface analysis The Task Force wanted to explore the impact of limiting impervious cover through regulating development and redevelopment. The impact of decreased imperviousness across the Morningside neighborhood was evaluated. The analysis showed an impervious limit would have little impact on flood risk. Although an impervious limit or reduction supports other values such as open space, room for trees, neighborhood character, and limiting heat island effect, the case for flood risk reduction was weak. Additionally, setting impervious limits would require a large financial investment. The impervious area that is directly connected to the storm sewer system in the Morningside neighborhood is estimated to be about 25% of the total land area, in aggregate. The analysis tested the sensitivity to changes in impervious by modifying the stormwater model so that the imperviousness of the entire contributing drainage area was increased, decreased, and even lowered all the way to 0%, which reflects a pre-development condition. This sensitivity test was also completed for a range of storm events, from the 20%-annual-chance storm event (5-year storm) to the 1%-annual-chance storm event (100-year storm). As expected, the imperviousness sensitivity test showed that less impervious area generates less stormwater runoff and more impervious area generates more stormwater runoff. However, the magnitude of the runoff changes generated by adjusting imperviousness were not as impactful as may have been expected. Additionally, the little flood reduction benefit shown in the analysis does not consider future climate change. A memorandum describing the analysis in more detail is available in the appendix. 22 Impervious limit: in progress item Impervious limit: in progress item At their February 12th, 2020 Planning Commission meeting heard an introduction to a zoning ordinance amendment which would limit impervious cover. Current code includes only a building coverage limit. Outreach and Engagement What is the outcome; People understand their vulnerability and exposure to flooding, know what action to take to reduce each in the immediate, short and long term. People have the knowledge and resources to take action. People are motivated to take action to protect themselves. Who does the work; Engineering Department, Communications Department, partner agencies, community groups. Who is involved; The public, and public and private organizations. When flooding risk is considered; In anticipation of spring melt, during flood events, post-hazard recovery, property transfers, upon FEMA flood hazard map update. Gaps; No coordinated plan and message, limited public and private resources. Knowledge alone doesn’t equal action. Although not at the same scale as a capital item, engaging the public still costs money. Equity should be considered in tactics. When people understand the risks of flooding, they can take actions to reduce the consequences of flooding. Actions could range from simple things, like moving valuables to higher floors, to more complex retrofit improvements like flood proofing and sanitary sewer backflow prevention. Risk awareness could be encouraged by improved distribution of information products like the existing flood risk map available on the City’s website. This local map is industry leading, with few small cities producing and publicly sharing detailed local flooding information. Although the information had been public for a long time, it had been in a format that required some technical knowledge to interpret. With new mapping tools, increasingly detailed digital stormwater system data, and more precise data about topography of the landscape, we’re better able to visualize risk. 23 Outreach products: in progress item Outreach products: in progress item Through the process, we uncovered some ‘quick-win’ actions that could be implemented immediately. • Actions for Flood Resilient Homes Fact Sheets. These two-page fact sheets describe common actions that people can take to reduce their own exposure and vulnerability to flooding. A copy of the draft fact sheets are provided in the Council work session meeting packet. The complete set of fact sheets is expected to be finalized within the month. • “What is my flood risk?” interactive map. This application allows users to visualize the flooding on the land surface for any property in the City of Edina. This information is already available on the interactive water resources map; however, this application is more focused on communicating flood risk specifically. Once finalized, the map will be available on the Maps page of the City website. The application can be previewed at a temporary weblink at; https://barrgisonline.maps.arcgis.com/apps/webappviewer/index.html?id=79c2a16b53af475dbc2 84cd2df9e4fee • Sandbagging how-to videos. The City provides sandbags, free of charge. This series of videos will be used to promote the service, inform people on how to request sandbags, demonstrate how to build a sandbag dike, and describe how to dispose of sandbags after a flood. Video production is anticipated to occur this spring. Emergency Services What is the outcome; Parties respond to remove people from harm, or prevent damage to property if possible, or provide aid after damage occurs. Limited disturbance/damage. Rapid return to normalcy. Who does the work; Police Department, Fire Department, Engineering Department, Public Works Department, County/State/Federal Emergency Responders, other infrastructure owners, and private contractors. Who is involved; Emergency operations command, emergency responders, the public, property owners, visitors, other infrastructure owners. When flooding risk is considered; In emergency operations plans, disaster planning, training and drills, post-hazard recovery. Gaps; Current response is triggered in major/severe events, the utility group’s first priority is to maintain or reestablish function of infrastructure systems, call centers can be overwhelmed and need clear triage procedure, there is nearly no service available for property owners during a flood, process of after-action inquiry, questions and blame that realize long-known service gaps is adversarial and leads 24 to rushed planning. A request or complaint-based response may not provide an equitable distribution of services. The City’s role in emergency situations include responding to life, health and safety calls and supporting or restoring the operation of the utilities. When floods occur the ability to respond effectively quickly degrades as phone lines and other communications channels fill with requests and reports. The ability to sort and serve these requests goes into triage with critical system function and support measures competing with urgent requests from the public. Empowering people to adapt to flood risk, prepare for flood events, and mitigate the impacts of climate change all contribute to a more resilient community. Adaptation and preparedness actions work to mitigate the consequences of flooding. Strategy Development Task Force role and process In order to incorporate community values into the process, a volunteer Task Force of eight Edina residents was formed. Members represent homeowners with a range knowledge and experience. Most have experienced flooding on their properties or have engaged with flood issues in the larger community. Members came from all across the City of Edina. Task Force members met 12 times and attended two City Council work sessions between July 2019 and March 2020. The Morningside neighborhood was selected as the focal area of study due to the presence of significant modeling and research in the area. The Morningside neighborhood faces a range of flooding challenges that past efforts have struggled to address. As part of this effort, a 2-dimensional model was developed and field calibrated to better refine the flood model and relate the models of St Louis Park and Minneapolis. The Morningside neighborhood was also used as the case study neighborhood for evaluating impervious limits, private storage, big infrastructure, and future climate change as noted in the various analysis sections of this report. The Task Force’s charge was to “Provide recommendations to inform a Flood Risk Reduction Strategy to be considered for adoption by the City Council and incorporation as a major amendment to the City’s Comprehensive Water Resources Management Plan.” The products of this process including meeting agendas, minutes, and analyses are available for review in the Water Resources Library on the City of Edina website. To better understand the nature of the issue, Task Force members requested and were presented with the following: • Overview of the focal area of Morningside neighborhood, its historical and current flood challenges, and previous efforts to evaluate flood risk reduction options. • A technical exploration of City-owned stormwater infrastructure, maintenance operations, levels of service, and the stormwater utility. 25 • Regulatory options that have been implemented in other comparable communities and associated challenges and trade-offs. • Modeled sensitivity analysis completed by Barr Engineering to explore the potential impact of comprehensive impervious limits, private stormwater storage, and enhanced infrastructure including larger pipes and stormwater storage. • Communications strategies that promote preparedness and connect residents with resources during flood events. • Overview of the City’s floodplain management ordinance and participation in the National Flood Insurance Program. • The City’s policy and standards for stormwater management through the permit process, related to development and redevelopment. • A conversation with maintenance staff to understand routine operation and maintenance as well as storm response. Interacting directly with the Task Force has provided staff members with insight into public perception of their role in flood risk reduction. During these conversations, staff began to see certain discrepancies between the following City assumptions; perception of risk, interpretation of the term ‘flooding’, and the role of City services. • How does the City define flood risk? Flood risk has been seen as a combination of the statistical probability of a flood event happening and the potential community-wide losses that occur as a consequence of that event. In the City of Edina, the increasing value of homes located within the floodplain is occurring in tandem with changing weather patterns that increase intensity of storm events, both of which increase the overall risk. The City’s idea of current flood risk is also being shaped by changing community expectations for service. • Defining “flooding” is similarly complicated by social perception. FEMA defines flooding as “A general and temporary condition of partial or complete inundation of 2 or more acres of normally dry land area or of 2 or more properties…” When intense or prolonged rain events occur, the system can become overwhelmed. A wet basement, flooded garage, or standing water may not fit FEMA’s definition, but each impacts the community and was considered “flooding” by Task Force members. • City services play a critical role in the following common flooding issues; creeks outside their banks, curb lines flowing full, storm drains clogging, pipes running full, low points in streets or yards filling up and threatening structures, flow paths eroding, sump pumps flowing, basement foundations leaking, and sanitary sewers backing up. Community service expectations are mismatched with available resources for preventative maintenance and timely emergency response to these issues. Staff heard the following sentiments from the Task Force; • Flooding affects quality of life by disrupting daily activities, risking safety, and damaging structures. 26 • A priority should be to reduce risk to residential structures. • Help property owners protect themselves and prevent damage to structures. • Be ready to help the community recover after floods. • Maintain the function of the existing system to maintain service. • Be a good neighbor. Brainstorming, prioritizing, and categorizing possible actions A series of actions were proposed for a possible menu or toolbox of actions as a result of discussions with the Task Force. Each action was accompanied by a detailed description, justification/motivating factors, tradeoffs and other considerations, cost score, staff-ranked effectiveness score, community enthusiasm ranking, and action category. The brainstorming exercise resulted in more than 40 potential actions. Reviewing and ranking these actions was no small task. Task Force members were asked to rank possible flood risk reduction actions based on community enthusiasm, informed by community held positions and interests related to flooding. Positions are surface statements of where a person or community stands. Interests are the underlying reasons, values or motivations that explain a certain position. Based on perceived community position and interests, the Task Force was asked to rank the action items in terms of community enthusiasm. Enthusiasm is the community’s interest or approval of the action. Considerations for community enthusiasm include tradeoffs, community impacts, land, sustainability, environmental outcomes, and social outcomes. Task Force members shared their hesitation in representing the community with their rankings because they felt that each flood experience was unique and they hadn’t had sufficient information or opportunity to gauge community enthusiasm at this detailed level. A summary of the aggregated Task Force rankings is included in the appendix with this caveat - in the end, the conversations around actions provided the most value for staff in forming the framework and strategy. The process helped to identify quick-win actions that could be implemented immediately, clarified areas of agreement and disagreement between the Task Force and staff, and will be used as a starting point for future Comprehensive Water Resources Management Plan program development work. We would expect rankings to be continually refined as more people participate and more information becomes available. The exercise itself outweighs the absolute ranking of the actions. The full set of possible actions as well the Task Force ranking summary is included in the appendix of this report. Conclusion The process has reiterated the need to address flooding with a range of strategies that span technical, scientific, political, and social approaches. Many communities are struggling with managing increasing flood risk. Key takeaways: 27 • The current stormwater model helps to better visualize where the issues are; they are extensive, interwoven, and difficult to solve. The existing stormwater system is overloaded and the strategy to put water somewhere else is limited. • Climate change impacts are significant. • Groundwater levels are increasing. The years between 2015 and 2019 were the wettest in Minnesota history. • The Flood Risk Reduction Strategy widens our approaches, and thereby actions, to reduce flood risk. The current Comprehensive Water Resources Management Plan is narrow and can’t keep up with the lead driver; climate change. • There are opportunities to empower people and institutions to adapt, prepare, and mitigate. The Strategy opens the approach of reducing vulnerability. Often, some of the simplest and most cost-effective ways to reduce risk are for people to reduce the vulnerability of their structures and property. • Impervious surfaces matter; however, the opportunity to reduce flood risk by limiting or reducing impervious cover in the City of Edina is limited. • Additional resources are needed to implement actions. • Residents have high expectations for service. • Other promising opportunities exist for operation and maintenance, public infrastructure (though climate change will make transformational change a challenge), and redevelopment standards anchored in resiliency. Lastly, there is an opportunity to knit together the emerging Flood Risk Reduction Strategy with the existing Living Streets Plan and forthcoming Climate Adaptation Plan. Bringing these efforts into focus and examining strategies through an equity lens are necessary to deliver high-value benefits to the community. Next steps Staff will finalize the Flood Risk Reduction Strategy based on Council and task force feedback from the work session and propose to bring the finalized report to the April 7th City Council meeting for final approval. Staff will prepare a scope of service for preliminary engineering for stormwater infrastructure related to the roadway reconstruction projects in the Morningside C, D and E maintenance groups scheduled for reconstruction in 2022 and 2023. Staff will also ask Council to consider the engagement plan to go along with the project design. This would be the first major roadway reconstruction project to be designed under the proposed Flood Risk Reduction Strategy. Staff will prepare a scope of service to complete a major amendment to the Comprehensive Water Resources Management Plan in order to incorporate the Flood Risk Reduction Strategy into the policies and implementation actions of that Plan. 28 Summary of proposed next steps; 1. Council considers approval of Flood Risk Reduction Strategy. 2. Council considers approval of preliminary engineering scope of service for the Morningside D/E and Morningside C neighborhood roadway reconstruction projects in 2022 and 2023, respectively. 3. Council considers approval of Morningside Neighborhood roadway reconstruction design engagement plan. 4. Council considers approval of scope of service for major amendment to Comprehensive Water Resources Management Plan. Acknowledgement Staff would like to thank the Task Force for their contributions. The experience, knowledge, and curiosity they brought to the process added value and influenced the Strategy. Nora Davis (co-chair), Lake Cornelia Neighborhood Kathy Amlaw (co-chair), Lake Edina Neighborhood Greg Lincoln, Morningside Neighborhood Michael Platteter, Morningside Neighborhood Louise Segreto, Indian Hills Neighborhood Roxane Lehmann, Sunny Slope Neighborhood Richard Strong, Concord Neighborhood Richard Manser, Todd Park Neighborhood 29 Appendix Appendix A: ‘Groundwater levels are increasing: summary of monitoring data’, technical memo In development, memo to be included in appendix for final report. Appendix B: ‘Getting to scale: a challenging problem made even more challenging, climate change impact analysis’, technical memo Draft graphics to visually show the impact of climate change (191015 Climate visualization_1of2.PDF and 191015 Climate visualization_2of2.PDF) are available for review in the Water Resources Library on the City of Edina website, to be finalized and included in appendix for final report. Appendix C: ‘Go Big, Go Bigger: infrastructure analysis’, technical memo Draft concept analysis report (191015 Infrastructure analysis_1of2.PDF and 191015 Infrastructure analysis_2of2.PDF) is available for review in the Water Resources Library on the City of Edina website, to be finalized and included in appendix for final report. Appendix D: ‘Keep your water to yourself: private infrastructure analysis’, technical memo Draft analysis report (191015 Private infrastructure analysis.PDF) is available for review in the Water Resources Library on the City of Edina website, to be finalized and included in appendix for final report. Appendix E: ‘From ‘ill-drained’ to impervious: impervious surface analysis’, technical memo Draft versions (191015 Map of Edina_1908.PDF and 191015 Impervious surface analysis.PDF) are available for review in the Water Resources Library on the City of Edina website, to be finalized and included in appendix for final report. Appendix F: Actions for Flood Resilient Homes, fact sheets Draft fact sheets provided, to be finalized and included for final report. Appendix G: Task Force charge Available for review in the Water Resources Library on the City of Edina website, to be included in appendix for final report. Appendix H: Potential action matrix key, ranked response, and potential action matrix Actions for Flood Resilient Homes: Actions and Programs Overview Surface water ooding Sanitary back ow Groundwater seepage Where does the water in my home come from? Flood waters come from di erent sources. No matter the source, all can cause extensive damage to your home. Depending on the situation, di erent strategies will work better than others to prevent damage to your property from the excess water. Gathering more information about how the water is entering your home, such as through a home drainage assessment, will help you choose the correct solution. Typical scenarios can include: Sanitary back ow ooding can be caused by a blockage in the city’s sewer system. This normally occurs when the sewer pipes are ooded with stormwater. When this happens, wastewater can ow backwards—into your home. Severe storms or prolonged periods of wet weather can cause water levels in creeks, ponds, lakes, and rivers to rise and over ow their banks. If your home is near these water bodies or in a low-lying area, it can be at risk of ooding. Surface water can also cause what’s known as “ ash ooding.” Because it occurs with little notice, ash ooding can catch people o guard. This normally occurs when existing drainage systems are overwhelmed by extremely heavy rain. Instead of soaking into the ground or draining through stormwater sewers, the water ows over the land surface, collecting in low-lying areas. Urban areas can be particularly vulnerable to ash ooding due to a greater amount of impervious surface. Groundwater can also be a source of ooding. This tends to occur after long periods of heavy rain or snowmelt, when more water in ltrates the ground and causes the groundwater to rise above the home’s foundation level. There’s no doubt about it. No matter where you live in the Twin Cities area, it’s been tough to stay dry. In fact, the years between 2015 and 2019 were the wettest in Minnesota history. And, with our changing climate, we can expect more wet years, more powerful storms—and more ooding. The City of Edina is committed to making this a ood-resilient community. That’s why we’ve adopted a ood-risk-reduction strategy that includes helping our residents make their homes and property ood resilient. To encourage you to do what you can to minimize your ood risk, we’ve developed factsheets on ood prevention and mitigation strategies. These factsheets, on topics ranging from sump pumps to sandbags, are now available on our website. They’re designed to get you thinking about ways to protect your home and provide you with information about available resources. For more information on ﬂ ood resilience, contact the Engineering Department at 952-826-0371. D R A F T D R A F T D R A F T Surface water ooding D R A F T Surface water ooding Where does the water in my home come from?D R A F T Where does the water in my home come from? Flood waters come from di erent sources. No matter the source, all can cause extensive damage to your home. Depending D R A F T Flood waters come from di erent sources. No matter the source, all can cause extensive damage to your home. Depending on the situation, di erent strategies will work better than others to prevent damage to your property from the excess water. D R A F T on the situation, di erent strategies will work better than others to prevent damage to your property from the excess water. Gathering more information about how the water is entering your home, such as through a home drainage assessment, will D R A F T Gathering more information about how the water is entering your home, such as through a home drainage assessment, will help you choose the correct solution. Typical scenarios can include: D R A F T help you choose the correct solution. Typical scenarios can include: Sanitary back ow ooding can be caused by a blockage in the city’s sewer system. D R A F T Sanitary back ow ooding can be caused by a blockage in the city’s sewer system. This normally occurs when the sewer pipes are ooded with stormwater. When D R A F T This normally occurs when the sewer pipes are ooded with stormwater. When Severe storms or prolonged periods of wet weather can cause water levels in creeks, D R A F T Severe storms or prolonged periods of wet weather can cause water levels in creeks, ponds, lakes, and rivers to rise and over ow their banks. If your home is near these water D R A F T ponds, lakes, and rivers to rise and over ow their banks. If your home is near these water bodies or in a low-lying area, it can be at risk of ooding. Surface water can also cause D R A F T bodies or in a low-lying area, it can be at risk of ooding. Surface water can also cause what’s known as “ ash ooding.” Because it occurs with little notice, ash ooding can catch D R A F T what’s known as “ ash ooding.” Because it occurs with little notice, ash ooding can catch people o guard. This normally occurs when existing drainage systems are overwhelmed by D R A F T people o guard. This normally occurs when existing drainage systems are overwhelmed by extremely heavy rain. Instead of soaking into the ground or draining through stormwater D R A F T extremely heavy rain. Instead of soaking into the ground or draining through stormwater sewers, the water ows over the land surface, collecting in low-lying areas. Urban areas can D R A F T sewers, the water ows over the land surface, collecting in low-lying areas. Urban areas can be particularly vulnerable to ash ooding due to a greater amount of impervious surface. D R A F T be particularly vulnerable to ash ooding due to a greater amount of impervious surface. strategy that includes helping our residents make their homes and property ood resilient. To encourage you to do what you D R A F T strategy that includes helping our residents make their homes and property ood resilient. To encourage you to do what you can to minimize your ood risk, we’ve developed factsheets on ood prevention and mitigation strategies. These factsheets, on D R A F T can to minimize your ood risk, we’ve developed factsheets on ood prevention and mitigation strategies. These factsheets, on topics ranging from sump pumps to sandbags, are now available on our website. They’re designed to get you thinking about D R A F T topics ranging from sump pumps to sandbags, are now available on our website. They’re designed to get you thinking about ways to protect your home and provide you with information about available resources.D R A F T ways to protect your home and provide you with information about available resources. For more information on ﬂ ood resilience, contact the Engineering Department at 952-826-0371. Actions can reduce exposure or vulnerabilityHome retro tting and ood prevention devices The table below provides a quick overview of some common actions you can take to create more ood resilient buildings and landscapes. The fact sheets that follow provide in-depth information on how, when, and where to use these actions and additional resources for residents. Building action Yard action Intervention action City permit requiredDNR permit requiredWatershed permit requiredGroundwater oodingSurface water oodingSanitary back owRelative Cost Before oodDuring oodAfter oodReduceexposureReduces vulnerabilitySump pump x x x Low x x Sanitary back ow prevention x x Medium x x Dry oodproo ng x x x Med-High x x Sandbags x Low x x Wet oodproo ng x x x High x x x Basement and low-level area pumping x x x Low x Rain gardens and landscape changes1,2 x*x*x Medium x x Shoreline restoration3 x*x x High x x Backyard element siting4 x*x x Low x x Actions for Flood Resilient Homes: Actions and Programs Overview Reduces vulnerabilityReduces exposure The extent to which property, homes, buildings, infrastructure, and other assets come into contact with ood water. The extent to which an exposed asset is able to resist ood-related damage. 1Rain gardens may require a City permit if grading over 10 cubic yards 2Rain gardens may require a permit from the watershed district. To learn more about your watershed visit: http://www.ninemilecreek.org or http://www.minnehahacreek.org 3DNR permit may be required, visit https://www.dnr.state.mn.us/rys/index.html for more info. 4Setbacks and structure count may apply, contact the City Planning Department for more info. Placeholder area for TBD image Placeholder area for TBD image D R A F T D R A F T D R A F T Actions can reduce exposure or vulnerability D R A F T Actions can reduce exposure or vulnerabilityHome retro tting and D R A F T Home retro tting and ood prevention devices D R A F T ood prevention devices The table below provides a quick overview of some D R A F T The table below provides a quick overview of some common actions you can take to create more ood D R A F T common actions you can take to create more ood resilient buildings and landscapes. The fact sheets D R A F T resilient buildings and landscapes. The fact sheets that follow provide in-depth information on how, D R A F T that follow provide in-depth information on how, when, and where to use these actions and additional D R A F T when, and where to use these actions and additional D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F TSurface water D R A F TSurface water oodingD R A F T oodingSanitary D R A F TSanitary back owD R A F Tback owRelative D R A F T Relative Cost D R A F T Cost Before oodD R A F TBefore oodDuring oodD R A F TDuring oodAfter oodD R A F TAfter oodReduceD R A F TReduceexposureD R A F TexposureReduces D R A F TReduces Low D R A F T Low x D R A F T x x D R A F T x D R A F T D R A F T D R A F T D R A F T Reduces exposure D R A F T Reduces exposure The extent to which property, D R A F T The extent to which property, homes, buildings, infrastructure, D R A F T homes, buildings, infrastructure, and other assets come into D R A F T and other assets come into contact with ood water. D R A F T contact with ood water. D R A F T Placeholder area for TBD image D R A F T Placeholder area for TBD image Take Action! The following factsheets describe actions that can protect your home from damage related to ooding. Not all actions will bene t your home; a proper home drainage assessment can help you understand which measures will be best for your situation. Many measures will require assistance from professional contractors and may require city permits. Please refer to each factsheet for additional information. Flood Insurance The City of Edina participates in the National Flood Insurance Program which enables anyone residing in Edina to purchase a National Flood Insurance Program ood insurance policy. Your homeowners or renters insurance agent may also be able to help you purchase ood insurance. A list of participating providers can be found here: https://www. oodsmart.gov/ nd Home Drainage Assessment Improper drainage can cause water damage during even minor rain or snow melt events. Whether you’re an owner or a renter, the “Home Drainage Basics” factsheet can help you assess problem areas where you live. Adopt-A-Drain By committing to keep drains clear of trash, leaves, grass, snow, and ice you can help prevent ooding—not to mention keeping Minnesota’s lakes, streams, and rivers free of pollutants. For greater impact, consider working with a friend or your neighbors to adopt multiple drains. More information on the Adopt-A-Drain program can be found by visiting: https://www.adopt-a-drain.org/ Actions for Flood Resilient Homes: Programs and Assessments Described below are a few ways to take action in the ght against ooding. Consider ood insurance and a home drainage assessment to protect your home; consider adopting a drain to protect the environment and your community. For more information on ﬂ ood resilience, contact the Engineering Department at 952-826-0371. D R A F T D R A F T Take Action! D R A F T Take Action! The following factsheets describe D R A F T The following factsheets describe actions that can protect your home D R A F T actions that can protect your home from damage related to ooding. Not D R A F T from damage related to ooding. Not all actions will bene t your home; a D R A F T all actions will bene t your home; a D R A F T The City of Edina participates in the National Flood D R A F T The City of Edina participates in the National Flood Insurance Program which enables anyone residing in D R A F T Insurance Program which enables anyone residing in Edina to purchase a National Flood Insurance Program D R A F T Edina to purchase a National Flood Insurance Program Adopt-A-Drain D R A F T Adopt-A-Drain By committing to keep drains clear of trash, leaves, grass, D R A F T By committing to keep drains clear of trash, leaves, grass, snow, and ice you can help prevent ooding—not to D R A F T snow, and ice you can help prevent ooding—not to mention keeping Minnesota’s lakes, streams, and rivers free D R A F T mention keeping Minnesota’s lakes, streams, and rivers free of pollutants. For greater impact, consider working with a D R A F T of pollutants. For greater impact, consider working with a friend or your neighbors to adopt multiple drains. D R A F T friend or your neighbors to adopt multiple drains. More information on the Adopt-A-Drain program can be found D R A F T More information on the Adopt-A-Drain program can be found by visiting: https://www.adopt-a-drain.org/ D R A F T by visiting: https://www.adopt-a-drain.org/ D R A F T D R A F T D R A F T D R A F T Actions for Flood Resilient Homes: Flood Insurance According to the Federal Emergency Management Agency (FEMA), ooding is the most common natural disaster in the United States and the consequences can be costly. Even 1 inch of water can cause $25,000 damage to your home. While homeowner’s insurance policies do not typically cover ood damage, the good news is that you can purchase separate protection. Because the City of Edina participates in the National Flood Insurance Program (NFIP), all of its residents are eligible to purchase ood insurance. Who needs ood insurance? Under federal law, if your home is within, or touches, a high-risk ood area and you have a mortgage on the property, you will be required to purchase ood insurance. Homes considered to be at high risk are those located within the 100-year oodplain—areas where there is a 1% annual risk of water rising above the base ood elevation. If you live near an area of past ooding you should consider purchasing ood insurance. Even if you don’t live in or near a high- risk area, ood insurance can be a wise investment. In fact, more than 20 percent of ood insurance claims come from properties outside of high-risk ood zones. And, compared to the cost of paying back a disaster loan, ood insurance is a bargain. The Minnesota Commerce Department calculates that the average payment on a $50,000 disaster loan is $240 per month ($2,880) for 30 years, while a $100,000 ood insurance premium is about $400 per year ($33 per month). Flood insurance is not limited to homeowners; it is also available to renters and owners of non-residential buildings. How do I nd out about my risk of ooding? To learn about your speci c risk of ooding, go to the City of Edina’s interactive ood risk map or visit FEMA’s Flood Map Service Area (https://msc.fema.gov/portal/home). is required to drain sump water to the storm sewer. How do I buy insurance? You can start by contacting the agent who provides your auto, homeowner’s, or renter’s insurance. He or she may be able to help you purchase ood insurance. If your insurance agent does not sell ood insurance, you can contact the NFIP Help Center at 800-427-4661. What does ood insurance cover? You can purchase separate coverage for your home and its contents; both are recommended for the best protection. Make sure your policy contains a comprehensive list of items covered. Almost all walled and roofed buildings above ground can be covered. Coverage available for basements typically includes foundation elements (including posts or other support systems), utility connections, and necessary mechanical equipment (e.g., furnace, hot water heater, clothes washer and dryer, food freezer, air conditioner, electrical junction). Items typically found in nished basements—paneling, carpeting, furniture—are not covered. You must normally wait 30 days after you’ve paid your premium before your policy will be e ective. Other considerations Losses from sewer backup are not covered by ood insurance unless the backup occurs as a result of surface water ooding. You may want to consider purchasing a rider on your homeowner’s policy to protect you from sewer backups not related to ooding. COST: $150-$12,0001 Costs are variable based on whether the location of the structure being insured above or below the base ood elevation, if the policy holder is a home-owner or renter, and many other factors. Due to the numerous variables, the best way to learn what your costs would be is to contact multiple providers and utilize the resources at the bottom of this page. For more information on ﬂ ood resilience, contact the Engineering Department at 952-826-0371. 1According to the Minnesota Department of Commerce, the average cost for a ood insurance policy is $500 per year. In low-to-moderate risk areas insurance can cost just over $100 per year. A Renters’ policy can range from $150-900 according to the Policygenius website: https://www.policygenius.com/renters-insurance/what-renters-need-to-know-about- ood-insurance/ Other Resources: FEMA National Flood Insurance Program: www. oodsmart.gov Minnesota Department of Commerce Flood Insurance Basics: https://mn.gov/commerce/consumers/your-home/protect/other/ oods/basics.jsp Minnesota Department of Natural Resources Flood Insurance FAQs: https:// les.dnr.state.mn.us/publications/waters/ oodplain_management_fact_sheet_8.pdf Before ood action During ood action After ood action D R A F T purchase ood insurance. D R A F T purchase ood insurance. Who needs ood insurance? D R A F T Who needs ood insurance? Under federal law, if your home is within, or touches, a high-risk ood area and you have a mortgage on the property, you will be D R A F T Under federal law, if your home is within, or touches, a high-risk ood area and you have a mortgage on the property, you will be required to purchase ood insurance. Homes considered to be at high risk are those located within the 100-year oodplain—areas D R A F T required to purchase ood insurance. Homes considered to be at high risk are those located within the 100-year oodplain—areas where there is a 1% annual risk of water rising above the base ood elevation.D R A F T where there is a 1% annual risk of water rising above the base ood elevation. If you live near an area of past ooding you should consider purchasing ood insurance. Even if you don’t live in or near a high-D R A F T If you live near an area of past ooding you should consider purchasing ood insurance. Even if you don’t live in or near a high- risk area, ood insurance can be a wise investment. In fact, more than 20 percent of ood insurance claims come from properties D R A F T risk area, ood insurance can be a wise investment. In fact, more than 20 percent of ood insurance claims come from properties outside of high-risk ood zones. And, compared to the cost of paying back a disaster loan, ood insurance is a bargain. The D R A F T outside of high-risk ood zones. And, compared to the cost of paying back a disaster loan, ood insurance is a bargain. The Minnesota Commerce Department calculates that the average payment on a $50,000 disaster loan is $240 per month ($2,880) for D R A F T Minnesota Commerce Department calculates that the average payment on a $50,000 disaster loan is $240 per month ($2,880) for 30 years, while a $100,000 ood insurance premium is about $400 per year ($33 per month). D R A F T 30 years, while a $100,000 ood insurance premium is about $400 per year ($33 per month). Flood insurance is not limited to homeowners; it is also available to renters and owners of non-residential buildings. D R A F T Flood insurance is not limited to homeowners; it is also available to renters and owners of non-residential buildings. D R A F T How do I nd out about my risk of ooding? D R A F T How do I nd out about my risk of ooding? To learn about your speci c risk of ooding, go to the City of D R A F T To learn about your speci c risk of ooding, go to the City of What does ood insurance cover? D R A F T What does ood insurance cover? You can purchase separate coverage for your home and its D R A F T You can purchase separate coverage for your home and its contents; both are recommended for the best protection. D R A F T contents; both are recommended for the best protection. Make sure your policy contains a comprehensive list of items D R A F T Make sure your policy contains a comprehensive list of items covered. D R A F T covered. Almost all walled and roofed buildings above ground can be D R A F T Almost all walled and roofed buildings above ground can be covered. Coverage available for basements typically includes D R A F T covered. Coverage available for basements typically includes D R A F T foundation elements (including posts or other support D R A F T foundation elements (including posts or other support systems), utility connections, and necessary mechanical D R A F T systems), utility connections, and necessary mechanical equipment (e.g., furnace, hot water heater, clothes washer D R A F T equipment (e.g., furnace, hot water heater, clothes washer and dryer, food freezer, air conditioner, electrical junction). D R A F T and dryer, food freezer, air conditioner, electrical junction). Items typically found in nished basements—paneling, D R A F T Items typically found in nished basements—paneling, D R A F T D R A F T D R A F T D R A F T During ood action D R A F T During ood action D R A F T D R A F T Actions for Flood Resilient Homes: Home Drainage Basics The graphic below shows common home drainage issues and solutions. Basic measures such as repositioning downspouts, grading away from your foundation, and seasonal home maintenance routines can help keep your home dry during heavy rainfall events. For more information on ﬂ ood resilience, contact the Engineering Department at 952-826-0371. http://www.ashireporter.org/HomeInspection/Articles/Keeping-Basements-Dry/1048 Turf to native planting conversion helps in ltrate stormwater and prevents ooding. The conversion can also be a money and water saver; native plants often require less water than turf lawns. Clearing stormsewer drains helps them perform e ectively. Drains frequently become clogged with stormwater debris, or blocked by snow and ice, which can cause water to accumulate and result in an over ow of water in the road and in lawns. Sump pump discharge pipe locations should follow the guidance provided on the Sump Pump Factsheet, following similar guidance for downspout to ensure water drains away from the home. Gutter installation is the key to directing water from your roof away from your home’s foundation. Too much water falling too close to your home can cause soil erosion, foundation problems, and water in the basement. Installing shields can prevent ooding through low-level windows. To protect window wells, create a gravel reservoir that allows water to slowly dissipate into the ground and install a cover. Rain gardens can provide areas for stormwater in ltration on your property. See Rain Garden Factsheet for details Proper downspout alignment helps to drain water away from the home. Make sure the downspout extension is at least 4–6 feet long and properly positioned to avoid water backup. Grading away from your home provides water with a path away from your home’s foundation, decreasing the likelihood of ooding. Inset images courtesy of: http://www.ashireporter.org/HomeInspection/Articles/Keeping-Basements-Dry/1048 D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T saver; native plants often D R A F T saver; native plants often require less water than D R A F T require less water than turf lawns. D R A F T turf lawns. helps them perform D R A F T helps them perform e ectively. Drains frequently D R A F T e ectively. Drains frequently stormwater debris, or blocked D R A F T stormwater debris, or blocked by snow and ice, which can D R A F T by snow and ice, which can cause water to accumulate and D R A F T cause water to accumulate and result in an over ow of water D R A F T result in an over ow of water in the road and in lawns.D R A F T in the road and in lawns. Rain gardens D R A F T Rain gardens can provide areas for D R A F T can provide areas for stormwater in ltration D R A F T stormwater in ltration on your property. D R A F T on your property. Rain Garden Factsheet D R A F T Rain Garden Factsheet for details D R A F T for details helps to drain water away from D R A F T helps to drain water away from the home. Make sure the downspout extension is at least 4–6 feet D R A F T the home. Make sure the downspout extension is at least 4–6 feet D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T Actions for Flood Resilient Homes: Sump Pumps What is a sump pump? A sump pump is a small pump installed in the lowest part of your basement. Its purpose is to collect subsurface water from the ground near your home’s foundation and pump it out to your yard to keep your basement dry. Who needs a sump pump? According to the American Society of Home Inspectors, 60% of homes in the United States have wet basements. If yours is one of them—or if one of the conditions below applies—you should consider installing a sump pump. • Your basement has ooded • You live in a low-lying area (see the interactive ood risk map ) • You have a nished basement where you store valuables (including appliances such as a washer/dryer) • You live in an area that receives signi cant amounts of rain or experiences rapid snow melt How does a sump pump work? The sump pump usually stands in a “sump pit,” which is a hole about 2 feet deep and 18 inches wide. Water from the soil around your home’s foundation ows into the sump pit through drains. Once that water reaches a certain level in the pit a pressure sensor or oat activator (similar to the one in your toilet), turns the pump on. The activated pump moves the water out of the pit through a pipe that should empty onto the ground at least 20 feet away from your home. In the City of Edina a utility connection permit is required to drain sump water to the storm sewer. Reduces vulnerability Reduces exposure COST: $400 (median MN)1 Sump tank Sump pump 3/4” Clear gravel Foundation drain tile pipe Interior drainage system 2” Discharge pipe Check valve FINISHED FLOOR ELEVATION BASEMENT FLOOR For more information on ﬂ ood resilience, contact the Engineering Department at 952-826-0371. 1According to improvenet.com (2020) for cost of replacement sump pump installation. May be substantially higher for new pumps, depending on type of pump/ ooring and location. Groundwater Before ood action During ood action After ood action D R A F T Who needs a sump pump? D R A F T Who needs a sump pump? According to the American Society of Home Inspectors, 60% of homes D R A F T According to the American Society of Home Inspectors, 60% of homes in the United States have wet basements. If yours is one of them—or D R A F T in the United States have wet basements. If yours is one of them—or if one of the conditions below applies—you should consider installing a D R A F T if one of the conditions below applies—you should consider installing a sump pump. D R A F T sump pump. Your basement has ooded D R A F T Your basement has ooded You live in a low-lying area (see the D R A F T You live in a low-lying area (see the interactive ood risk map D R A F T interactive ood risk map You have a nished basement where you store valuables D R A F T You have a nished basement where you store valuables (including appliances such as a washer/dryer) D R A F T (including appliances such as a washer/dryer) You live in an area that receives signi cant amounts of rain or D R A F T You live in an area that receives signi cant amounts of rain or experiences rapid snow melt D R A F T experiences rapid snow melt D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T 2” Discharge pipe D R A F T 2” Discharge pipe D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T During ood action D R A F T During ood action D R A F T For more information on ﬂ ood resilience, contact the Engineering Department at 952-826-0371. Sump pump standards can be found at: https://www.edinamn.gov/DocumentCenter/View/397/Sump-Pump-Discharge-Connection-Policy-PDF Information on utility connection permits can be found at: https://epermits2.logis.org/home.aspx?city=ed Sump Drain Detail: https://www.edinamn.gov/DocumentCenter/View/848/310---Sump-Drain-PDF Sump Drain Connection Detail: https://www.edinamn.gov/DocumentCenter/View/849/311---Sump-Drain-Service-Connection-PDFInstalling sump pump require a permit: https://www.edinamn.gov/209/Building-Permits-Resources Actions for Flood Resilient Homes: Sump Pumps Connecting your sump pump to City of Edina storm sewers: • The pipe exiting the house should have an air gap and drain to an area that slopes away from your home’s foundation. Direct the drainage away from your home toward green areas that in ltrate water or toward public drainage paths. • Sump drain lines can connect your sump pump directly to the storm sewer. This is best done by a licensed professional and requires a permit from the City of Edina. Other Considerations • Gutters can signi cantly a ect the water that gets into your basement. Make sure your gutters are well maintained and large enough to handle heavy rains. Downspouts should be directed away from the home. Similarly, make sure that the land next to your home is properly graded—directing water away from the foundation. • Sump pumps should be checked regularly, particularly in early spring and when heavy rains are forecast. To test your pump, pour a bucket of water into the pit to make sure it starts automatically and that the water pumps out quickly. • Pump maintenance should include removing the pump from the pit and cleaning the grate on the bottom. You should also make sure that if you are using a discharge pipe, the air gap is clear. The air gap is located outside your home, where the sump pump’s internal discharge line exits the basement and connects to the external discharge line. Its purpose is to provide an outlet for ows in the event there is a problem with the discharge line or the stormwater system. • A standard 15-amp, 110-volt, three-pronged grounded electrical outlet can handle a sump pump. The outlet should be an isolated line, with no other connections between the breaker and the outlet. Because the pump is located near water you may want to plug it into a working ground fault circuit interrupter (GFCI). However, keep in mind that lightening has been known to trigger GFCIs and could shut o power to your pump during a heavy rainstorm. Make certain to check on the pump during the storm so you can reset the GFCI if necessary. • Consider replacing your sump pump every 10 years. Make sure your sump pump is ready for whatever water comes its way … Sump pumps often come with water-level or ood alarms to alert you if the pump fails. Some can even call your cell phone or notify your alarm company. To minimize the risk of ooding, test your sump pump periodically to make sure it is in good operating condition. Your user’s manual should specify when and how to test your pump. You can also consider investing in a backup pump to operate if the primary pump fails or becomes overwhelmed with water from a large storm. Similarly, because sump pumps operate on electricity, they are vulnerable to power outages. Pumps with backup battery power are available, or a generator can be used. Placeholder area for TBD image D R A F T your home is properly graded—directing water away from the foundation. D R A F T your home is properly graded—directing water away from the foundation. Sump pumps should be checked regularly, particularly in early spring and when heavy rains are forecast. To test your pump, D R A F T Sump pumps should be checked regularly, particularly in early spring and when heavy rains are forecast. To test your pump, pour a bucket of water into the pit to make sure it starts automatically and that the water pumps out quickly.D R A F T pour a bucket of water into the pit to make sure it starts automatically and that the water pumps out quickly.D R A F T D R A F T D R A F T D R A F T Pump maintenance should include removing the pump from the pit and cleaning the grate on the bottom. You should also D R A F T Pump maintenance should include removing the pump from the pit and cleaning the grate on the bottom. You should also make sure that if you are using a discharge pipe, the air gap is clear. The air gap is located outside your home, where the sump D R A F T make sure that if you are using a discharge pipe, the air gap is clear. The air gap is located outside your home, where the sump pump’s internal discharge line exits the basement and connects to the external discharge line. Its purpose is to provide an D R A F T pump’s internal discharge line exits the basement and connects to the external discharge line. Its purpose is to provide an outlet for ows in the event there is a problem with the discharge line or the stormwater system. D R A F T outlet for ows in the event there is a problem with the discharge line or the stormwater system. A standard 15-amp, 110-volt, three-pronged grounded electrical outlet can handle a sump pump. The outlet should be an D R A F T A standard 15-amp, 110-volt, three-pronged grounded electrical outlet can handle a sump pump. The outlet should be an isolated line, with no other connections between the breaker and the outlet. Because the pump is located near water you may D R A F T isolated line, with no other connections between the breaker and the outlet. Because the pump is located near water you may want to plug it into a working ground fault circuit interrupter (GFCI). However, keep in mind that lightening has been known D R A F T want to plug it into a working ground fault circuit interrupter (GFCI). However, keep in mind that lightening has been known to trigger GFCIs and could shut o power to your pump during a heavy rainstorm. Make certain to check on the pump during D R A F T to trigger GFCIs and could shut o power to your pump during a heavy rainstorm. Make certain to check on the pump during the storm so you can reset the GFCI if necessary. D R A F T the storm so you can reset the GFCI if necessary. Consider replacing your sump pump every 10 years. D R A F T Consider replacing your sump pump every 10 years. Placeholder area for TBD image D R A F T Placeholder area for TBD image For more information on ﬂ ood resilience, contact the Engineering Department at 952-826-0371. 1According to HomeAdvisor (2020). Costs to install a back ow preventer (including device) depend on the size and type of system. Note that many insurance companies o er discounts to homeowners who install sanitary back ow prevention devices. What is a sanitary back ow prevention device/ back ow valve? A sanitary back ow prevention device is a valve attached to your plumbing system. It is designed to prevent over ow waste water from the city’s sewer system from backing up into your home. Who needs a sanitary back ow prevention device? Because sanitary back ow prevention devices can prevent the signi cant damage caused by sewer backup, the city of Edina recommends them for all homes. If you have a newer home a valve may have been installed during construction. Back ow valves are usually located in the oor; if you have a sump pump the valve is likely to be close by. Note that many insurance companies o er discounts to homeowners who install sanitary back ow prevention devices. The city recommends that back ow prevention devices be installed by a licensed plumber. A permit is required for this installation. How do sanitary back ow prevention devices work? A back ow valve has a ap with small oaters on both sides that allow the ap to open and close. Under normal conditions, the ap is open—allowing water from your home to ow into the main sewer system. However, if a large storm or snow melt overwhelms the sewer system, causing water or sewage to back ow toward the house, the oaters will close the ap, e ectively shutting your home o from the street sewer system (see detail above). Once the street sewer system has chance to drain and return to normal functioning, the ap opens again to discharge waste water. Due to the potential for clogging, occasional inspection of the device is needed. Reduces vulnerability Reduces exposure COST: $135-$10001 Backﬂ ow preventer location Sewer lateral Sewer main BASEMENT Water level House sanitary sewer line Sanitary back ow prevention device detail (Image Credit: Mainline Back ow Products) Sanitary back ow prevention devices overview Actions for Flood Resilient Homes: Sanitary Back ow Prevention Devices Before ood action During ood action After ood action D R A F T D R A F T D R A F T Who needs a sanitary back ow prevention device? D R A F T Who needs a sanitary back ow prevention device? Because sanitary back ow prevention devices can prevent the D R A F T Because sanitary back ow prevention devices can prevent the signi cant damage caused by sewer backup, the city of Edina D R A F T signi cant damage caused by sewer backup, the city of Edina recommends them for all homes. If you have a newer home a D R A F T recommends them for all homes. If you have a newer home a valve may have been installed during construction. Back ow valves D R A F T valve may have been installed during construction. Back ow valves are usually located in the oor; if you have a sump pump the valve D R A F T are usually located in the oor; if you have a sump pump the valve is likely to be close by. D R A F T is likely to be close by. Note that many insurance companies o er discounts to homeowners D R A F T Note that many insurance companies o er discounts to homeowners who install sanitary back ow prevention devices. The city recommends D R A F T who install sanitary back ow prevention devices. The city recommends that back ow prevention devices be installed by a licensed plumber. A D R A F T that back ow prevention devices be installed by a licensed plumber. A permit is required for this installation. D R A F T permit is required for this installation. D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T During ood action D R A F T During ood action D R A F T D R A F T For more information on ﬂ ood resilience, contact the Engineering Department at 952-826-0371. Actions for Flood Resilient Homes: Sanitary Back ow Prevention Devices Make sure you’re ready for sewer backups … Back ow prevention devices can function automatically or be operated manually. To protect your home, the valve must be closed during overload periods—which will vary with the size of the storm, but typically last from 2 to 6 hours. Be aware that during the time the valve is closed you will not be able to use your plumbing. Other Considerations • You should have your back ow prevention device cleaned and checked annually, preferably by the licensed plumber that installed it. • To avoid back ow in your home plumbing system, keep your plumbing free of materials such as diapers, sanitary napkins, and cigarette butts. • Backwater from a public sewer system is hazardous to your health. If sewer water enters your home you should hire a licensed and trained professional cleaning service (Top) Image of sewer backup in bathroom, courtesy of https:// blueskyplumbing .com/wp-content/uploads/2016/10/sewer- backup-in-bathroom.jpg (Right) Sanitary back ow prevention device install, image courtesy of https://www. ickr.com/photos/69302634@ N02/16327005228/in/photostream/ Sanitary back ow preventer installation D R A F T To avoid back ow in your home plumbing D R A F T To avoid back ow in your home plumbing system, keep your plumbing free of materials D R A F T system, keep your plumbing free of materials such as diapers, sanitary napkins, and cigarette D R A F T such as diapers, sanitary napkins, and cigarette Backwater from a public sewer system is D R A F T Backwater from a public sewer system is D R A F T D R A F T D R A F T hazardous to your health. If sewer water enters D R A F T hazardous to your health. If sewer water enters your home you should hire a licensed and D R A F T your home you should hire a licensed and trained professional cleaning service D R A F T trained professional cleaning service D R A F T D R A F T For more information on ﬂ ood resilience, contact the Engineering Department at 952-826-0371. 1The cost of dry oodproo ng varies depending on the building size, depth of required protection, types of material used, and number of openings. Examples of general cost estimates can be found in FEMA publications, Homeowner’s Guide to Retro tting: Six Ways to Protect Your House from Flooding and Engineering Principles and Practices of Retro tting Floodprone Residential Structures. What is dry oodproo ng? Dry oodproo ng describes a range of strategies to seal the exterior of a building from ood waters. Who should use dry oodproo ng? Dry oodproo ng is only viable for buildings that are structurally sound in areas with low-velocity, relatively shallow ooding (below 3 feet). It is most appropriate for slab-on-grade buildings with concrete or solid masonry walls. Due to risk of structural failure from excessive ood forces, dry oodproo ng is not advised for homes with basements or homes comprising weaker construction materials (e.g...., wood frame with siding). Note that dry oodproo ng residential structures will not reduce ood insurance premiums. What are dry oodproo ng methods? • Temporary installation of waterproof membranes: Heavy plastic sheeting or a waterproof membrane along a wall’s exterior can be e ective in preventing water from entering the home. • Use of sealants: Waterproof sealants can be applied to building walls, structural joints, and openings for utility lines. Cement and asphalt-based coatings are e ective, but can drastically change the appearance of the home and may be susceptible to puncturing. Clear coatings (e.g.., epoxies or polyurethanes) can be applied to exterior walls without changing appearance but tend to be less e ective. (continued on next page) Reduces exposure Reduces vulnerability COST: VARIES1 Actions for Flood Resilient Homes: Dry Floodproo ng (Above) “A way to seal an existing brick-faced wall is to add an additional layer of brick with a seal in between. Please note that weep holes (drainage) and wick drains are moved up to prevent moisture from getting inside the walls.” Images and descriptions provided by FEMA P-312, Homeowner’s Guide to Retro tting 3rd Edition (2014) (Left) Example of exterior application of asphalt membrane (courtesy of https://staydrywaterproo ng.com/) (Right) an interior application of a ber reinforced polymer wrap, image provided by FEMA P-312, Homeowner’s Guide to Retro tting 3rd Edition (2014) Before ood action During ood action After ood action D R A F T D R A F T Dry oodproo ng is only viable for buildings that are structurally D R A F T Dry oodproo ng is only viable for buildings that are structurally sound in areas with low-velocity, relatively shallow ooding (below D R A F T sound in areas with low-velocity, relatively shallow ooding (below 3 feet). It is most appropriate for slab-on-grade buildings with D R A F T 3 feet). It is most appropriate for slab-on-grade buildings with concrete or solid masonry walls. Due to risk of structural failure D R A F T concrete or solid masonry walls. Due to risk of structural failure from excessive ood forces, dry oodproo ng is not advised for D R A F T from excessive ood forces, dry oodproo ng is not advised for homes with basements or homes comprising weaker construction D R A F T homes with basements or homes comprising weaker construction materials (e.g...., wood frame with siding). D R A F T materials (e.g...., wood frame with siding). Note that dry oodproo ng residential structures will not reduce ood insurance premiums. D R A F T Note that dry oodproo ng residential structures will not reduce ood insurance premiums. What are dry oodproo ng D R A F T What are dry oodproo ng D R A F T D R A F T D R A F T D R A F T Before ood action D R A F T Before ood action D R A F T D R A F T During ood action D R A F T During ood action D R A F T For more information on ﬂ ood resilience, contact the Engineering Department at 952-826-0371. Other Considerations • The Federal Emergency Management Agency recommends that dry oodproo ng should be designed by licensed professionals. Failure to anticipate hydrostatic forces may result in extensive damage. • Placement of ood shields or waterproof membranes is not feasible during ash oods or when warning times are short. • Ongoing maintenance is required. • Flood shields and sealants may not be aesthetically pleasing. • Dry oodproo ng does not mitigate the potential impact of high-velocity ood ow, wave action, erosion, or debris. Actions for Flood Resilient Homes: Dry Floodproo ng • Addressing closures: Openings in the walls need to be either temporarily or permanently sealed shut. For example, low window openings at ground level can either have a pre-sized closure tted over their surface or a low wall constructed around the opening. Similarly, all or part of a low window could be replaced with brick or glass block. • Using ood shields: Temporary watertight shields can be placed over windows or doors in anticipation of ooding. Most residential shields can be stored in the home and installed when needed by bolting them into place or securing them in permanently installed brackets or tracks. • Addressing interior drainage: A good interior drainage system to collect leaking water (e.g., a sump pump with an emergency power source) is an important component of a dry oodproo ng system. Sanitary back ow prevention is also recommended. (Above) Metal shields installed with bolts or permanently installed tracks. image courtesy of:www.ps oodbarriers.com/wp-content/uploads/ sites/4/2016/09/Flood-Plank-21.jpg (Left) Low window raised and original opening lled with brick, image provided by FEMA P-312, Homeowner’s Guide to Retro tting 3rd Edition (2014) What are dry oodproo ng methods? (continued)D R A F T D R A F T D R A F T Ongoing maintenance is required. D R A F T Ongoing maintenance is required. Flood shields and sealants may not be aesthetically pleasing. D R A F T Flood shields and sealants may not be aesthetically pleasing. Dry oodproo ng does not mitigate the potential impact of high-velocity ood ow, wave action, erosion, or debris.D R A F T Dry oodproo ng does not mitigate the potential impact of high-velocity ood ow, wave action, erosion, or debris.D R A F T Addressing closures D R A F T Addressing closures: Openings in the walls need D R A F T : Openings in the walls need to be either temporarily or permanently sealed D R A F T to be either temporarily or permanently sealed shut. For example, low window openings at ground D R A F T shut. For example, low window openings at ground level can either have a pre-sized closure tted over D R A F T level can either have a pre-sized closure tted over their surface or a low wall constructed around the D R A F T their surface or a low wall constructed around the opening. Similarly, all or part of a low window could D R A F T opening. Similarly, all or part of a low window could be replaced with brick or glass block. D R A F T be replaced with brick or glass block. Temporary watertight D R A F T Temporary watertight D R A F T shields can be placed over windows or doors in D R A F T shields can be placed over windows or doors in anticipation of ooding. Most residential shields can D R A F T anticipation of ooding. Most residential shields can D R A F T What are dry oodproo ng methods? D R A F T What are dry oodproo ng methods? For more information on ﬂ ood resilience, contact the Engineering Department at 952-826-0371. 1Costs vary depending on the size of the area to be protected. Under severe ood conditions, it may be necessary to build a sandbag dike to protect your home from water damage. Sandbags that are properly lled and placed can successfully divert water—moving it around buildings rather than allowing it to ow through them. The information below outlines the materials and steps necessary to build a sandbag dike. Sandbag materials Sandbags themselves are generally made of treated burlap or woven polypropylene and measure approximately 24 inches by 14 inches. A sandy soil is best for lling sandbags, but other available materials (silt, clay, gravels, or a mixture) may be used. Sandbags can be found online and in hardware stores. Some local sources of sand or gravel include: • Bjorklund & Companies, 763-444-9301 • D-Rock Center, 651-639-0446 • Hage Concrete Works, 612-861-4243 • Hedberg Supply, Landscape & Masonry, 763-545-4400 • Marshall Concrete Products, 612-789-4303 • North Star Packaging, 952-249-0661 • Plaisted Companies, 763-441-1100 Filling a sandbag Filling and deploying sandbags is usually a three- person job: one person to hold the bag open, one person to shovel sand, and a third person to position the bag. The use of gloves is advised, as well as safety goggles. Bags should be lled about one-half to two-thirds full and will weigh approximately 35-40 pounds. Untied bags are recommended for most applications. Reduces exposure Reduces vulnerability COST: VARIES1 Actions for Flood Resilient Homes: Sandbags Placing sandbags Remove any debris from the area before placing sandbags. To avoid placing stress on walls, you should leave at least 8 feet between the dike and the building you want to protect. Place the rst layer of bags lengthwise, parallel to the direction of the water ow. The bags should be “lapped” so that the lled portion of one bag lies on the un lled portion of the next. The untied end should be facing downstream. Similar to brick laying, o set adjacent rows or layers by one- half bag length to eliminate continuous joints. To form a tight seal, walk on the bags as they are placed and continue walking on them as succeeding layers are added. Because bags may remain untied, make certain to fold under all loose ends. image: https://www.disaster.qld.gov.au/dmp/sandbagging/Pages/default.aspx Before ood action During ood action After ood action How to make a request • During regular business hours, requests can be made by calling in to the Public Works utility line, 952-826-0375. • On weekends, requests can be made by calling in to the non-emergency police to get routed to the on-call person. • Leave name, address, and the quantity of sandbags desired. If you’re unsure, describe the size of the area and Public Works can help to determine how many are needed. City provided sandbags: Public Works delivers sand bags to residents when requested, and will leave sand bag pallets at the end of the property driveway. Requests are typically ful lled within 24 hours. Residents must place the sand bags themselves – Public Works sta does not place sandbags. When sandbags are no longer needed, residents may keep the sandbags or place them back on the pallet and call Public Works for pick-up. D R A F T Public Works delivers sand bags to residents when requested, D R A F T Public Works delivers sand bags to residents when requested, and will leave sand bag pallets at the end of the property D R A F T and will leave sand bag pallets at the end of the property driveway. Requests are typically ful lled within 24 hours. D R A F T driveway. Requests are typically ful lled within 24 hours. Residents must place the sand bags themselves – Public Works D R A F T Residents must place the sand bags themselves – Public Works sta does not place sandbags.D R A F T sta does not place sandbags. When sandbags are no longer needed, residents may keep D R A F T When sandbags are no longer needed, residents may keep D R A F T D R A F T D R A F T Sandbags themselves are generally made of treated D R A F T Sandbags themselves are generally made of treated Placing sandbags D R A F T Placing sandbags Remove any debris from the area before placing sandbags. To D R A F T Remove any debris from the area before placing sandbags. To avoid placing stress on walls, you should leave at least 8 feet D R A F T avoid placing stress on walls, you should leave at least 8 feet between the dike and the building you want to protect. D R A F T between the dike and the building you want to protect. Place the rst layer of bags lengthwise, parallel to the D R A F T Place the rst layer of bags lengthwise, parallel to the direction of the water ow. The bags should be “lapped” so D R A F T direction of the water ow. The bags should be “lapped” so that the lled portion of one bag lies on the un lled portion D R A F T that the lled portion of one bag lies on the un lled portion of the next. The untied end should be facing downstream. D R A F T of the next. The untied end should be facing downstream. Similar to brick laying, o set adjacent rows or layers by one- D R A F T Similar to brick laying, o set adjacent rows or layers by one- half bag length to eliminate continuous joints. To form a tight D R A F T half bag length to eliminate continuous joints. To form a tight seal, walk on the bags as they are placed and continue walking D R A F T seal, walk on the bags as they are placed and continue walking on them as succeeding layers are added. Because bags may D R A F T on them as succeeding layers are added. Because bags may remain untied, make certain to fold under all loose ends. D R A F T remain untied, make certain to fold under all loose ends. D R A F T D R A F T D R A F T Before ood action D R A F T Before ood action D R A F T D R A F T During ood action D R A F T During ood action D R A F T the sandbags or place them back on the pallet and call Public D R A F T the sandbags or place them back on the pallet and call Public Works for pick-up. D R A F T Works for pick-up. For more information on ﬂ ood resilience, contact the Engineering Department at 952-826-0371. Other Considerations Sandbags can become contaminated with bacteria and other pathogens from polluted ood waters. The sand from these bags should never be used in children’s sandboxes. Full sandbags may be stored for short periods of time and reused for same-season ood ghting. However, prolonged storage can lead to mold. According to the Minnesota Pollution Control Agency, the safest place to dispose of full sandbags is a sanitary land ll. Sandbags may also be disposed in a demolition land ll. Be aware, however, that not all land lls will accept sandbags, so call rst. Actions for Flood Resilient Homes: Sandbags How high and how wide should my dike be? The U.S. Army Corps of Engineers recommends that your dike should have a base three times wider than its height, although a ratio of 2:1 is also commonly recommended. A triangular pyramid shape should be used for a dike that is higher than 1 foot. For heights less than a foot, support the wall of sandbags every 5 feet with clusters of bags; this will stabilize the structure. How many bags will I need? The North Dakota State Extension Service o ers the following estimates for the number of sandbags needed per 100 linear feet of dike. Dike Height 3:1 base to height 2:1 base to height 2 foot 2,100 bags 1,700 bags 3 foot 4,500 bags 3,000 bags 4 foot 7,800 bags 5,500 bags 5 foot 12,000 bags 9,000 bags Sealing the dike To improve water tightness, your nished dike should be sealed with a sheet of plastic at least 6 mils thick. First, spread a loose layer of soil or sand about 1 inch deep and 1 foot wide along the bottom of the dike on the water side. Then, lay the plastic sheeting so the upper edge extends over the top of the dike and the bottom extends 1 foot beyond the bottom of the dike (over the layer of soil and sand). Be careful not to stretch the plastic too tight; this could lead to puncturing. Finally, put a row of sandbags on the bottom and top edges of the plastic to form a watertight seal and hold it in place. Be careful to avoid puncturing the plastic by walking on it. Sandbag alternatives Alternatives to sandbags include “sandless” sandbags and Hydrabarriers, which can be purchased online or at some hardware stores. The sandless bags are made of an absorbent polymer that swells on contact with water—basically self-in ating the bags to form a water barrier. The Hydrabarrier is a tube (available in di erent sizes) that you ll with water to form a barrier. The advantage of these systems is that they are lighter weight, reusable, and do not pose a disposal problem. The disadvantage is that these systems can be expensive to purchase image: http://goldenlake.co/ Even when properly installed, water can leak and rain may fall inside the barrier. Be prepared with a pump to remove water from inside the barrier. D R A F T D R A F T D R A F T lead to mold. According to the Minnesota Pollution Control Agency, the safest place to dispose of full sandbags is a sanitary land ll. D R A F T lead to mold. According to the Minnesota Pollution Control Agency, the safest place to dispose of full sandbags is a sanitary land ll. Sandbags may also be disposed in a demolition land ll. Be aware, however, that not all land lls will accept sandbags, so call rst. D R A F T Sandbags may also be disposed in a demolition land ll. Be aware, however, that not all land lls will accept sandbags, so call rst. How high and how wide should my dike be?D R A F T How high and how wide should my dike be? The U.S. Army Corps of Engineers recommends that your dike should D R A F T The U.S. Army Corps of Engineers recommends that your dike should have a base three times wider than its height, although a ratio of 2:1 is D R A F T have a base three times wider than its height, although a ratio of 2:1 is also commonly recommended. A triangular pyramid shape should be D R A F T also commonly recommended. A triangular pyramid shape should be used for a dike that is higher than 1 foot. For heights less than a foot, D R A F T used for a dike that is higher than 1 foot. For heights less than a foot, support the wall of sandbags every 5 feet with clusters of bags; this will D R A F T support the wall of sandbags every 5 feet with clusters of bags; this will How many bags will I need? D R A F T How many bags will I need? The North Dakota State Extension Service o ers the following D R A F T The North Dakota State Extension Service o ers the following estimates for the number of sandbags needed per 100 linear feet of D R A F T estimates for the number of sandbags needed per 100 linear feet of D R A F T D R A F T D R A F T 2:1 base to height D R A F T 2:1 base to height D R A F T D R A F T For more information on ﬂ ood resilience, contact the Engineering Department at 952-826-0371. 1Costs of wet oodproo ng vary with the methods adopted. Major costs are associated with rearrangement of utility systems, installation of ood vents, and replacement of materials that are not resistant to oods. Note that wet oodproo ng residential structures will not reduce ood insurance premium rates on residential structures. What is wet oodproo ng? Wet oodproo ng refers to a range of strategies used to prevent or provide resistance to ood damage—while allowing water into the uninhabited portion of a building (e.g., un nished basement, crawlspace, garage). Allowing oodwater to enter the enclosed areas of a home equalizes pressure, which can prevent structural damage. Successful wetproo ng involves (1) ensuring that oodwaters inside the home rise and fall at the same rate as oodwaters outside the home, (2) reducing damage through the use of ood-resistant materials, (3) protecting service equipment inside and outside of the home, and (4) relocating any high-value items stored below the designed ood elevation (DFE). • Elevate appliances and utilities or install barriers: Items that should be elevated or protected with a barrier include your furnace and air-conditioning unit, outside air-conditioner compressor, washer and dryer, water heater, freezer, and electrical outlets and switches. You can also relocate these to a place in your home that is higher than the DFE (e.g., an attic), or build a small addition that would serve as a utility room and as storage for valuable furnishings during a ood. • Use ood-resistant materials: The Federal Emergency Management Agency (FEMA) publishes ood-resistant classi cations for ooring, wall, and ceiling materials, as well as the adhesives used to install them (Technical Bulletin 2-08). Carpeting, paneling, and gypsum wallboard can all be replaced with materials that would require cleaning rather than replacement.A table on the following page lists materials that are acceptable in wet oodproo ng home projects. (continued on next page) Actions for Flood Resilient Homes: Wet Floodproo ng Reduces exposure Reduces vulnerability COST: VARIES1 Before ood action During ood action After ood action Wet oodproo ng techniques for a house. Image from FEMA P-259 (Figure -10) https://www.restoration1greaterminneapolis.com/how-to-deal-with-a- ooded-basement What are wet oodproo ng methods? An advantage of wet oodproo ng is that it is exible; it can be done in stages—many of them relatively inexpensively. A good time to employ wet oodproo ng strategies is when you remodel your home. The following are some wet oodproo ng methods: Base fl ood elevation Who should use wet oodproo ng? If you are at risk of ooding and cannot elevate your home or build reliable ood barriers, wet oodproo ng of non-living spaces is an option. It is most suitable for shallow ooding that inundates uninhabited space. It is not practical for most slab-on-grade structures that have the living space at or near ground level. Also, it is not a reasonable approach if the duration of a ood is expected to be more than one day. D R A F T D R A F T a building (e.g., un nished basement, D R A F T a building (e.g., un nished basement, crawlspace, garage). Allowing oodwater D R A F T crawlspace, garage). Allowing oodwater to enter the enclosed areas of a home D R A F T to enter the enclosed areas of a home equalizes pressure, which can prevent D R A F T equalizes pressure, which can prevent structural damage. Successful wetproo ng D R A F T structural damage. Successful wetproo ng involves (1) ensuring that oodwaters inside D R A F T involves (1) ensuring that oodwaters inside the home rise and fall at the same rate as D R A F T the home rise and fall at the same rate as oodwaters outside the home, (2) reducing D R A F T oodwaters outside the home, (2) reducing damage through the use of ood-resistant D R A F T damage through the use of ood-resistant materials, (3) protecting service equipment D R A F T materials, (3) protecting service equipment inside and outside of the home, and (4) D R A F T inside and outside of the home, and (4) relocating any high-value items stored below D R A F T relocating any high-value items stored below D R A F T D R A F T D R A F T D R A F T During ood action D R A F T During ood action D R A F T D R A F T https://www.restoration1greaterminneapolis.com/how-to-deal-with-a- ooded-basement D R A F T https://www.restoration1greaterminneapolis.com/how-to-deal-with-a- ooded-basement An advantage of wet oodproo ng is that it is exible; it can be done in stages—many of them relatively inexpensively. D R A F T An advantage of wet oodproo ng is that it is exible; it can be done in stages—many of them relatively inexpensively. A good time to employ wet oodproo ng strategies is when you remodel your home. The following are some wet D R A F T A good time to employ wet oodproo ng strategies is when you remodel your home. The following are some wet D R A F T D R A F T For more information on ﬂ ood resilience, contact the Engineering Department at 952-826-0371. Other Considerations • Ongoing maintenance is required to minimize ood risks. • Pumping water from a basement too soon after a ood may lead to structural damage. • Work on electrical systems, gas systems, or air- conditioning compressors requires a licensed contractor, and permits may be required. Actions for Flood Resilient Homes: Wet Floodproo ng What are wet oodproo ng methods? (continued) Materials that are acceptable in wet oodproo ng home project: Material Type Acceptable Unacceptable Structural Flooring Materials • Concrete • Naturally decay-resistant lumber • Pressure-treated plywood • Oriented-strand board (OSB) Finish Flooring Materials • Clay tile • Ceramic or porcelain tile • Terrazzo tile • Vinyl tile or sheets • Engineered wood or laminate ooring • Carpeting • Wood ooring Structural Wall and Ceiling Materials • Brick face, concrete, or concrete block • Cement board / ber-cement board • Pressure-treated plywood • Solid, standard structural lumber (2x4) • Non-paper-faced gypsum board • Fiberglass insulation • Paper-faced gypsum board • OSB Finish Wall and Ceiling Materials • Glass blocks • Metal cabinets or doors • Latex paint • Wood cabinets and doors • Non-latex paint • Particleboard cabinets and doors • Wallpaper FEMA P-312, Homeowner’s Guide to Retro tting 3rd Edition (2014) • Sewage back ow prevention is important; a back ow valve should be installed. • Because wet oodproo ng allows your home to ood, extensive cleanup may be necessary to remove potential chemical and biological contamination and prevent mold growth and decay. • Install ood vents: Flood vents (permanent openings) allow water into the structure, equalizing interior and exterior pressures to avoid structural damage. (Above) “Wall openings must allow oodwaters not only to enter the home, but also to rise and fall at the same rate as oodwaters outside the home.” Images provided by FEMA P-312, Homeowner’s Guide to Retro tting 3rd Edition (2014) (Left) Base ood elevation and location of ood vents. Images provided by FEMA Technical Bulletin 2, 2008, Openings in Foundation Walls and Walls of Enclosures. Base fl ood elevation D R A F T D R A F T D R A F T ood may lead to structural damage. D R A F T ood may lead to structural damage. Work on electrical systems, gas systems, or air- D R A F T Work on electrical systems, gas systems, or air- conditioning compressors requires a licensed D R A F T conditioning compressors requires a licensed contractor, and permits may be required.D R A F T contractor, and permits may be required. What are wet oodproo ng methods? (continued)D R A F T What are wet oodproo ng methods? (continued) Materials that are acceptable in wet oodproo ng home project: D R A F T Materials that are acceptable in wet oodproo ng home project: D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T D R A F T Material Type D R A F T Material Type Acceptable D R A F T Acceptable Structural Flooring Materials D R A F T Structural Flooring Materials • D R A F T • Concrete D R A F T Concrete • D R A F T • Naturally decay-resistant lumber D R A F T Naturally decay-resistant lumber • D R A F T • Pressure-treated plywood D R A F T Pressure-treated plywood • D R A F T • Clay tile D R A F T Clay tile Ceramic or porcelain tile D R A F T Ceramic or porcelain tile Terrazzo tile D R A F T Terrazzo tile Vinyl tile or sheets D R A F T Vinyl tile or sheets • D R A F T • Brick face, concrete, or concrete block D R A F T Brick face, concrete, or concrete block Cement board / ber-cement board D R A F T Cement board / ber-cement board Pressure-treated plywood D R A F T Pressure-treated plywood Solid, standard structural lumber (2x4) D R A F T Solid, standard structural lumber (2x4) Non-paper-faced gypsum board D R A F T Non-paper-faced gypsum board • D R A F T • Fiberglass insulation D R A F T Fiberglass insulation • D R A F T • Paper-faced gypsum board D R A F T Paper-faced gypsum board • D R A F T • OSB D R A F T OSB • D R A F T • Wood cabinets and doors D R A F T Wood cabinets and doors • D R A F T • Non-latex paint D R A F T Non-latex paint • D R A F T • Particleboard cabinets and doors D R A F T Particleboard cabinets and doors • D R A F T • Wallpaper D R A F T Wallpaper D R A F T FEMA P-312, Homeowner’s Guide to Retro tting 3rd Edition (2014) D R A F T FEMA P-312, Homeowner’s Guide to Retro tting 3rd Edition (2014) D R A F T Actions for Flood Resilient Homes: Pumping Guidance If dry oodproo ng methods fail during a large storm or you’ve chosen wet oodproo ng, you may end up with a signi cant amount of water in your basement. Though your impulse may be to remove the water as soon as possible, it’s important to remember that moving too quickly may cause structural damage to your home. Even though ood waters may have receded, there is still water in the ground that may be exerting force against your basement walls. If that force is greater than the force of water inside your basement, the foundation, basement walls, or oors may rupture or crack. Pumping Procedure—when and how much to pump? If you need to pump water out of your basement or house, the Federal Emergency Management Agency (FEMA) recommends taking the following steps to avoid serious damage to your home. 1. Begin pumping only when oodwaters are no longer covering the ground outside. 2. Pump out 1 foot of water, mark the water level, and wait overnight. 3. Check the water level the next day. If the level rose to the previous mark, it is still too early to drain the basement. 4. Wait 24 hours, pump the water down 1 foot, and mark the water level. Check the level the next day. 5. When the water level stops returning to your mark, pump out 2 to 3 feet and wait overnight. Repeat this process. daily until all of the water is out of the basement. Safety First! Remember that water conducts electricity. Before walking into a ooded basement make certain the power is turned o and wear heavy rubber boots and rubber gloves that do not leak. Reduces vulnerability Reduces exposure COST: VARIES1 For more information on ﬂ ood resilience, contact the Engineering Department at 952-826-0371. 1Costs rely on a number of factors—including the amount of water and whether you choose to do the pumping yourself. You can contract with a water-removal service, but you may have to wait several days for assistance. After ood action During ood action Before ood action D R A F T D R A F T D R A F T D R A F T D R A F T Pumping Procedure—when and how much to pump? D R A F T Pumping Procedure—when and how much to pump? If you need to pump water out of your basement or house, the Federal Emergency Management Agency (FEMA) D R A F T If you need to pump water out of your basement or house, the Federal Emergency Management Agency (FEMA) recommends taking the following steps to avoid serious damage to your home. D R A F T recommends taking the following steps to avoid serious damage to your home. 1. Begin pumping only when oodwaters are no longer covering the ground outside. D R A F T 1. Begin pumping only when oodwaters are no longer covering the ground outside. 3. Check the water level the next day. If the level rose to the previous mark, it is still too early to drain the basement. D R A F T 3. Check the water level the next day. If the level rose to the previous mark, it is still too early to drain the basement. 4. Wait 24 hours, pump the water down 1 foot, and mark the water level. Check the level the next day. D R A F T 4. Wait 24 hours, pump the water down 1 foot, and mark the water level. Check the level the next day. 5. When the water level stops returning to your mark, pump out 2 to 3 feet and wait overnight. Repeat this process. D R A F T 5. When the water level stops returning to your mark, pump out 2 to 3 feet and wait overnight. Repeat this process. D R A F T D R A F T During ood action D R A F T During ood action D R A F T Actions for Flood Resilient Homes: Pumping Guidance For more information on ﬂ ood resilience, contact the Engineering Department at 952-826-0371. Pumping Procedure—Equipment A submersible pump is needed to remove water from a ooded basement. You can rent this type of equipment from a construction rental store or a hardware store; this will be less expensive than purchasing professional pumping equipment. The pump is encased in a waterproof shell with a sealed electrical cord; it connects to a regular garden hose or a sump hose. The power source for the pump will depend on whether or not you have electricity. If you don’t have electricity you will need to connect to a generator. Be careful! Do not use gasoline-powered pumps or generators indoors; these can produce deadly carbon monoxide exhaust fumes. Note: opening doors and windows does not provide su cient ventilation. Another option is a pump that runs on a 12-volt marine or car battery or a petrol/diesel driven pump. If you do have power, you can use a heavy-duty extension cord to run the pump on standard electricity—provided you have a place to plug it in. If your fuse box isolates your basement and you are absolutely sure you can disable the power in the basement, you can use electricity on the ground oor or higher. No matter what energy source you use, you will need to be careful to keep the connection between the extension cord and the pump cord away from water. You can do this by looping the cords around a ceiling joist or another heavy object. Other Considerations • A second pump should be considered to provide increased capacity and act as a backup. • Strainers should be used to protect pumps from large debris. • Use clean, fresh fuel in your pump or generator and make sure you have enough available to act in a ood. • Be careful around oodwater that may have been contaminated by sewage. Tetanus shots are recommended when cleaning ooded areas. Pumping Procedure—Pumping out the water To pump water, a garden or sump hose should be attached to the tting on the top of the pump. The end of the hose is then pointed away from the house to drain away to the street or storm sewer If the water is low enough, you can place the pump in the lowest part of the basement, making sure to wear rubber boots. In the event of very high water, you can lower the pump into the basement using rope. Once the pump is in place, start the generator, plug the extension cord in, and turn the pump on. If you’re using electricity, plug the extension cord into an upstairs wall socket. If your water is less than an inch deep, a wet-dry vacuum can be used. These work well, but can be very labor intensive; the tank on a wet-dry vacuum generally holds only 4 to 5 gallons of water and will need to be emptied frequently. 1 inch of water in a 1500-2000 square foot home would be 1000-1200 gallons and would require approximately 250 empties! Placeholder area for TBD image Placeholder area for TBD image D R A F T D R A F T D R A F T Pumping Procedure—EquipmentD R A F T Pumping Procedure—Equipment A submersible pump is needed to remove water from a D R A F T A submersible pump is needed to remove water from a ooded basement. You can rent this type of equipment D R A F T ooded basement. You can rent this type of equipment from a construction rental store or a hardware store; this D R A F T from a construction rental store or a hardware store; this D R A F T will be less expensive than purchasing professional pumping D R A F T will be less expensive than purchasing professional pumping equipment. The pump is encased in a waterproof shell with a D R A F T equipment. The pump is encased in a waterproof shell with a sealed electrical cord; it connects to a regular garden hose or D R A F T sealed electrical cord; it connects to a regular garden hose or a sump hose. The power source for the pump will depend D R A F T a sump hose. The power source for the pump will depend on whether or not you have electricity. D R A F T on whether or not you have electricity. you will need to connect to a D R A F T you will need to connect to a generator. Be careful! Do not use gasoline-powered pumps D R A F T generator. Be careful! Do not use gasoline-powered pumps or generators indoors; these can produce deadly carbon D R A F T or generators indoors; these can produce deadly carbon D R A F T monoxide exhaust fumes. Note: opening doors and windows D R A F T monoxide exhaust fumes. Note: opening doors and windows Be careful around oodwater that may have been contaminated by sewage. Tetanus shots are recommended when cleaning D R A F T Be careful around oodwater that may have been contaminated by sewage. Tetanus shots are recommended when cleaning D R A F T D R A F T Placeholder area for TBD image D R A F T Placeholder area for TBD image For more information on ﬂ ood resilience, contact the Engineering Department at 952-826-0371. 1According to the Rain Garden Alliance: do-it-yourself rain garden will cost about $3–$5 a square foot. If you use a landscaper to plan and install the garden, the cost will be $10–$15 a square foot or more. Plants are the most costly consideration in a rain garden. Parts of the city of Edina are within the Nine Mile Creek Watershed District, which o ers cost-share grants for rain gardens. The minimum grant is $500 and requires a 25% match. To see if your home is located within the district and to learn more about the grant program, go to https://www.ninemilecreek.org/ What is a rain garden? A rain garden is a tool used to decrease runo and lter pollutants from stormwater. These gardens, built in shallow depressions, are lled with long-rooted grasses and plants that soak up rainwater from impervious surfaces—before the polluted ow enters lakes, rivers, and wetlands. Because they decrease runo , rain gardens are also useful in ood prevention. Once established, they require little watering and minimal maintenance. In addition to decreasing runo and ltering pollutants, rain gardens also create habitat for birds and butter ies, recharge groundwater, reduce mosquito breeding, and enhance property value. Actions for Flood Resilient Homes: Rain Gardens How do I plant a rain garden? There are many online resources that provide guidance on the construction and maintenance of rain gardens. Please see the reference section at the bottom of this factsheet for resources. Other Considerations: • Rain gardens require partial to full sun. They should be built at least 10 feet away from your home to prevent water damage to foundations and basements. • Rain gardens are typically 100 to 300 square feet, depending on the slope of the surrounding landscape and the size of the area draining into it; gardens will typically handle runo from an impervious area three times its size. More than one garden may be needed to handle runo from large surfaces (e.g., large rooftops). • To prevent plants from drowning and mosquitoes from breeding, a rain garden requires soil that is porous enough to soak up water within 48 hours of a rainstorm. You can test your soil by digging a wide 10-inch-deep hole, lling it with water, and observing it to see whether the water disappears within 48 hours. • Before you dig, contact Gopher State One Call (811) or visit http:// www.gopherstateonecall.org/to locate electrical, gas, or telephone lines. Who should use a rain garden? Rain gardens are particularly bene cial for those who have a large amount of nearby impervious surface (rooftops, walkways, driveways), have downspouts running into the lawn, or areas downhill from a downspout. They may also be helpful if you have soil erosion. (With deep-rooted plants, rain gardens hold soil in place and prevent erosion). image courtesy Minnehahacreek.org image courtesy Natural Shore: http://www.naturalshore.com/rain-garden-project-album/ Reduces vulnerability COST: VARIES1 Reduces exposure Before ood action During ood action After ood action D R A F T D R A F T D R A F T that soak up rainwater from impervious surfaces—before D R A F T that soak up rainwater from impervious surfaces—before the polluted ow enters lakes, rivers, and wetlands. Because D R A F T the polluted ow enters lakes, rivers, and wetlands. Because they decrease runo , rain gardens are also useful in ood D R A F T they decrease runo , rain gardens are also useful in ood prevention. Once established, they require little watering and D R A F T prevention. Once established, they require little watering and minimal maintenance. D R A F T minimal maintenance. In addition to decreasing runo and ltering pollutants, rain D R A F T In addition to decreasing runo and ltering pollutants, rain gardens also create habitat for birds and butter ies, recharge D R A F T gardens also create habitat for birds and butter ies, recharge groundwater, reduce mosquito breeding, and enhance D R A F T groundwater, reduce mosquito breeding, and enhance D R A F T construction and maintenance of rain gardens. Please see the reference D R A F T construction and maintenance of rain gardens. Please see the reference Who should use a rain garden? D R A F T Who should use a rain garden? Rain gardens are particularly bene cial for those who have a large amount of nearby impervious surface (rooftops, walkways, D R A F T Rain gardens are particularly bene cial for those who have a large amount of nearby impervious surface (rooftops, walkways, driveways), have downspouts running into the lawn, or areas downhill from a downspout. They may also be helpful if you have D R A F T driveways), have downspouts running into the lawn, or areas downhill from a downspout. They may also be helpful if you have soil erosion. (With deep-rooted plants, rain gardens hold soil in place and prevent erosion). D R A F T soil erosion. (With deep-rooted plants, rain gardens hold soil in place and prevent erosion). D R A F T D R A F T D R A F T D R A F T During ood action D R A F T During ood action D R A F T For more information on ﬂ ood resilience, contact the Engineering Department at 952-826-0371. What is shoreline restoration? Shoreline restoration involves the use of native vegetation to provide a bu er between your yard and the water’s edge. This bu er (10–50 feet) replaces turf grass. Although shoreline restoration does not reduce your exposure to ooding, it can reduce your vulnerability. Unlike turf grass, native trees, shrubs, forbs, and grasses have long roots that better withstand the e ects of ooding. Under lengthy, high-water conditions, this may prevent the need to replace ooded turf. Actions for Flood Resilient Homes: Shoreline Restoration How do I restore my lakeshore? “Restore Your Shores,” o ered by the Minnesota Department of Natural Resources (DNR) (https://www.dnr.state.mn.us/rys/index. html) provides online guidance for implementing shoreland restoration projects, including steps and techniques, a plant guide, and references and resources. Comprehensive guidance, pertinent to Minnesota landscapes, is also available in the book, “Lakescaping for Wildlife and Water Quality,” published by the Minnesota DNR. Or, consult a local landscaper who specializes in shoreline restoration. Reduces exposure COST: VARIES1 Reduces vulnerability Before ood action During ood action After ood action In addition to reducing ood vulnerability, shoreland restoration has a number of ecological bene ts: • Deep-rooted native plants are more resistant to wave and ice erosion and reduce the likelihood of slope failure. • Native plantings improve water quality by slowing and ltering runo before it enters the lake. • A mixture of native vegetation provides diverse habitat for sh and wildlife. • A bu er prevents wave action from stirring up sediment that can cause the lake to become murky. • A bu er area provides privacy and aesthetic views while discouraging nuisance geese. Other Considerations: • Some shoreline restoration projects will require a local or Minnesota Department of Natural Resources permit. Helpful websites: https://www.dnr.state.mn.us/lakescaping/index.html https://www.dnr.state.mn.us/publications/waters/shoreline_alteration.html D R A F T D R A F T D R A F T Although shoreline restoration does not reduce your exposure D R A F T Although shoreline restoration does not reduce your exposure to ooding, it can reduce your vulnerability. Unlike turf grass, D R A F T to ooding, it can reduce your vulnerability. Unlike turf grass, native trees, shrubs, forbs, and grasses have long roots that better D R A F T native trees, shrubs, forbs, and grasses have long roots that better withstand the e ects of ooding. Under lengthy, high-water D R A F T withstand the e ects of ooding. Under lengthy, high-water conditions, this may prevent the need to replace ooded turf.D R A F T conditions, this may prevent the need to replace ooded turf.D R A F T D R A F T D R A F T Before ood action D R A F T Before ood action D R A F T D R A F T During ood action D R A F T During ood action D R A F T D R A F T D R A F T Reduces vulnerability D R A F T Reduces vulnerability In addition to reducing ood vulnerability, shoreland D R A F T In addition to reducing ood vulnerability, shoreland restoration has a number of ecological bene ts: D R A F T restoration has a number of ecological bene ts: • D R A F T • Deep-rooted native plants are more resistant to wave D R A F T Deep-rooted native plants are more resistant to wave and ice erosion and reduce the likelihood of slope D R A F T and ice erosion and reduce the likelihood of slope failure. D R A F T failure. • D R A F T • Native plantings improve water quality by slowing and D R A F T Native plantings improve water quality by slowing and ltering runo before it enters the lake. D R A F T ltering runo before it enters the lake. • D R A F T • A mixture of native vegetation provides diverse habitat D R A F T A mixture of native vegetation provides diverse habitat for sh and wildlife. D R A F T for sh and wildlife. A bu er prevents wave action from stirring up sediment D R A F T A bu er prevents wave action from stirring up sediment that can cause the lake to become murky. D R A F T that can cause the lake to become murky. A bu er area provides privacy and aesthetic views while D R A F T A bu er area provides privacy and aesthetic views while discouraging nuisance geese. D R A F T discouraging nuisance geese. For more information on ﬂ ood resilience, contact the Engineering Department at 952-826-0371. Helpful websites https://www.epa.gov/green-infrastructure/manage- ood-risk https://www.homeadvisor.com/r/ ood-proof-landscaping/ https://www.owntheyard.com/how-to- x-backyard- ooding/ https://aibd.org/6-backyard- ooding-solutions-landscaping-storm-proof-yard/ The damage that can be caused by ood water doesn’t stop at your front door. The way you care for your yard and how you site and construct accessory structures can reduce both ood exposure and vulnerability. Actions for Flood Resilient Homes: Floodproo ng Accessory Structures And Yards Floodproo ng yards There are many options you can consider to reduce ooding in your yard. • Make sure your yard is properly graded: Patios, driveways, walkways, owerbeds—if possible, they should all be graded so that the water ows away from the house. • Install a rain garden: Rain gardens protect your yard from ooding by allowing runo water to pool and slowly percolate into the ground. See the City’s factsheet for more information on rain gardens. • Install dry wells: Dry wells are underground structures that help rainwater dissipate into the ground. They can be used for wet spots or small, ood-prone areas on your property. • Create or take advantage of natural swales: Swales are depressions in the landscape that redirect water ow, normally to a dry well or a garden bed with good drainage. You can slow the ow by lining the lowest point with rocks or adding deep-rooted plants on the slope. • Use heavier mulch: Light-weight mulch can spread under ooding conditions, clogging drains. If using mulch near your home’s exterior, make sure the mulch is at least six inches from your siding to prevent moisture wicking and rotting. • Replace impervious surfaces: Impervious (non-porous) surfaces increase runo . Replace them with pervious materials or landscaping. • Drain your driveway: Driveways are a big contributor to stormwater runo . You can mitigate the impact of that stormwater by adding drainage on the sides of the pavement—or by replacing the pavement with a pervious surface. • Plant a tree: Trees create a leafy canopy that intercepts rainfall and reduces runo . According to the Chesapeake Bay Foundation, a typical street tree can intercept from 500 to 760 gallons of water per year, depending on the species. Before ood action During ood action After ood action Floodproo ng accessory structures Your yard is an extension of your living space, which needs to be protected. The rst step in oodproo ng is to site the accessory structures on your property—your patio, re table/pit, garden shed, gazebo—on high ground. You can also reduce your vulnerability by building these structures with ood-resistant materials. See the City’s factsheet on Wet Floodproo ng for a list of ood-resistant materials. You should also secure yard items to prevent them from being damaged or swept away. Anchor them or attach them to more stable structures. Other considerations: Parts of the city of Edina are within the Nine Mile Creek Watershed District, which o ers cost-share grants for rain gardens. The minimum grant is $500 and requires a 25% match. To see if your home is located within the district and to learn more about the grant program, go to https://www.ninemilecreek.org/ D R A F T D R A F T D R A F T Floodproo ng accessory structuresD R A F T Floodproo ng accessory structures Your yard is an extension of your living space, which needs D R A F T Your yard is an extension of your living space, which needs to be protected. The rst step in oodproo ng is to site D R A F T to be protected. The rst step in oodproo ng is to site the accessory structures on your property—your patio, re D R A F T the accessory structures on your property—your patio, re D R A F T D R A F T There are many options you can consider to reduce ooding in your yard. D R A F T There are many options you can consider to reduce ooding in your yard. Patios, driveways, walkways, owerbeds—if possible, they should all be graded D R A F T Patios, driveways, walkways, owerbeds—if possible, they should all be graded : Rain gardens protect your yard from ooding by allowing runo water to pool and slowly D R A F T : Rain gardens protect your yard from ooding by allowing runo water to pool and slowly percolate into the ground. See the City’s factsheet for more information on rain gardens. D R A F T percolate into the ground. See the City’s factsheet for more information on rain gardens. Dry wells are underground structures that help rainwater dissipate into the ground. They can be used D R A F T Dry wells are underground structures that help rainwater dissipate into the ground. They can be used Swales are depressions in the landscape that redirect water ow, normally D R A F T Swales are depressions in the landscape that redirect water ow, normally to a dry well or a garden bed with good drainage. You can slow the ow by lining the lowest point with rocks or adding D R A F T to a dry well or a garden bed with good drainage. You can slow the ow by lining the lowest point with rocks or adding Light-weight mulch can spread under ooding conditions, clogging drains. If using mulch near your D R A F T Light-weight mulch can spread under ooding conditions, clogging drains. If using mulch near your home’s exterior, make sure the mulch is at least six inches from your siding to prevent moisture wicking and rotting. D R A F T home’s exterior, make sure the mulch is at least six inches from your siding to prevent moisture wicking and rotting. table/pit, garden shed, gazebo—on high ground. You can D R A F T table/pit, garden shed, gazebo—on high ground. You can also reduce your vulnerability by building these structures D R A F T also reduce your vulnerability by building these structures with ood-resistant materials. See the City’s factsheet on D R A F T with ood-resistant materials. See the City’s factsheet on Wet Floodproo ng for a list of ood-resistant materials. D R A F T Wet Floodproo ng for a list of ood-resistant materials. You should also secure yard items to prevent them from D R A F T You should also secure yard items to prevent them from being damaged or swept away. Anchor them or attach D R A F T being damaged or swept away. Anchor them or attach For more information on ﬂ ood resilience, contact the Engineering Department at 952-826-0371. Even if you don’t own a home, your property may be at risk during a ood. Below are some simple steps you can take to reduce that risk. In addition to decreasing runo and ltering pollutants, rain gardens also create habitat for birds and butter ies, recharge groundwater, reduce mosquito breeding, and enhance property value. Actions for Flood Resilient Homes: Reducing Risk as a Renter or Condo-Owner Consider buying ood insurance: It’s important to know that your regular renter’s insurance policy does not cover ooding. But, ood insurance is available for renters and condo owners through the National Flood Insurance Program (NFIP). The policy covers your personal property and contents during a ood. It does not include “loss-of-use” coverage or any additional expenses caused by a ood. Flood insurance premiums are based on a number of factors including ood risk, year of building construction, building occupancy, the number of oors, the location of your contents, and the deductible and amount of coverage you choose. Even if you live in a low-to-moderate risk area, it’s worth considering ood insurance. According to the NFIP, nearly 26 percent of all ood claims occur in these areas. Also, you may be eligible for a “preferred risk policy,” which carries the lowest premiums. The cost for renters’ ood insurance generally ranges from $150 to $900 per year. Though ood insurance is provided by the NFIP and prices are set by the NFIP, it is sold by private insurance companies. Contact your insurance agent to nd out whether he/she can provide coverage. If not, call the NFIP at 800-427-4661 to request an agent referral. If you decide to buy insurance, don’t wait for the next storm. There’s typically a 30-day waiting period between when the policy is purchased and when coverage applies. Consider the low spaces—including underground garages If you have personal items in the basement or garage, put them in covered, plastic containers and store them on shelving—o the oor. Similarly, don’t leave valuables in your car if ood waters are predicted. Get the facts First, nd out if the building where you live is in a high-risk ood area. You can check by going to the Federal Emergency Management Agency (FEMA) website https://msc.fema.gov/portal/search and entering your address. It’s also helpful to know what steps your landlord/association has taken to decrease the building’s exposure and vulnerability. Here are some questions you might ask: • Does the building structure have ood insurance? This may be important because it could in uence your landlord’s ability to recover following a ood—and your ability to continue living in the property. • Has the landlord/association taken ood resilience measures (wet oodproo ng, dry oodproo ng)? • Is there a sump pump in the building? Is there a sewer back ow prevention device? This is particularly important if you store personal items in the basement of the building. • Is there available above-ground storage in the event ood waters are predicted? • In the event of an impending ood will the landlord/association be responsible for sandbagging? If not, will you be allowed to sandbag? (See City factsheet on sandbagging for more information.) Helpful websites https://www.fema.gov/national- ood-insurance-program/How-Buy-Flood-Insurance https://www.policygenius.com/renters-insurance/what-renters-need-to-know- about- ood-insurance/ Floodwater level D R A F T It’s important to know that your regular renter’s insurance D R A F T It’s important to know that your regular renter’s insurance Consider the low spaces—including D R A F T Consider the low spaces—including underground garages D R A F T underground garages If you have personal items in the basement or garage, put D R A F T If you have personal items in the basement or garage, put them in covered, plastic containers and store them on D R A F T them in covered, plastic containers and store them on shelving—o the oor. Similarly, don’t leave valuables in D R A F T shelving—o the oor. Similarly, don’t leave valuables in your car if ood waters are predicted. D R A F T your car if ood waters are predicted. First, nd out if the building where you live is in a high-risk ood area. You can check by going to the Federal Emergency D R A F T First, nd out if the building where you live is in a high-risk ood area. You can check by going to the Federal Emergency Management Agency (FEMA) website https://msc.fema.gov/portal/search and entering your address. It’s also helpful to know D R A F T Management Agency (FEMA) website https://msc.fema.gov/portal/search and entering your address. It’s also helpful to know what steps your landlord/association has taken to decrease the building’s exposure and vulnerability. Here are some questions D R A F T what steps your landlord/association has taken to decrease the building’s exposure and vulnerability. Here are some questions you might ask:D R A F T you might ask: Does the building structure have ood insurance? This may be important because it could in uence your landlord’s ability D R A F T Does the building structure have ood insurance? This may be important because it could in uence your landlord’s ability to recover following a ood—and your ability to continue living in the property. D R A F T to recover following a ood—and your ability to continue living in the property. Has the landlord/association taken ood resilience measures (wet oodproo ng, dry oodproo ng)? D R A F T Has the landlord/association taken ood resilience measures (wet oodproo ng, dry oodproo ng)? Is there a sump pump in the building? Is there a sewer back ow prevention device? This is particularly important if you D R A F T Is there a sump pump in the building? Is there a sewer back ow prevention device? This is particularly important if you store personal items in the basement of the building. D R A F T store personal items in the basement of the building. Is there available above-ground storage in the event ood waters are predicted? D R A F T Is there available above-ground storage in the event ood waters are predicted? In the event of an impending ood will the landlord/association be responsible for sandbagging? If not, will you be allowed D R A F T In the event of an impending ood will the landlord/association be responsible for sandbagging? If not, will you be allowed to sandbag? (See City factsheet on sandbagging for more information.) D R A F T to sandbag? (See City factsheet on sandbagging for more information.) D R A F T Floodwater D R A F T Floodwater level D R A F T level D R A F T D R A F T Actions Sheets Key Sector: The sector of work under which the action would fall. Infrastructure (I), Regulatory Program (R), Outreach and Engagement (O), and Emergency Services (E). Task Force Rank: Based on aggregate of individual Task Force member rankings. Task Force members were asked to rank their top 10 with the action believed to have the most community enthusiasm ranked number 1 and the action believed to have the least community enthusiasm ranked number 10. Actions beyond 10 were effectively not ranked. Cost Score: Staff scored. $ Minor; Savings or efficiency, takes minor amount of staff time, or can roll into existing duties with existing staff time and resources, <0 to 20hrs, <0 to $2K $$ Modest; Modest additional costs, modest amount of staff time. 20 to 100hrs, $2-10K $$$ Moderate; Moderate additional costs, takes moderate amount of additional staff time, or can be contracted out in future budgets. 100-500hrs, $10-50K $$$$ High; Additional costs, takes additional staff time, can be contracted out with additional resources. 500-2000hrs, $50-200K $$$$$ Major; Significant costs, takes significant amount of staff time, or can be included in future capital improvement plans. 2000+hrs, $200K+ Staff Rated Effectiveness Score: Staff scored. Based on effectiveness and confidence at reducing community vulnerability to flooding, at reducing community exposure to flooding, and at reducing the community share of climate change drivers. Action Category: Quick Win = do now or contract under flood risk reduction effort. Planning = develop a plan as part of flood risk reduction effort, or include in Comprehensive Water Resources Management Plan amendment, future budget, or Capital Improvement Plan (CIP). Development = may be worth doing with additional resources, a special circumstance, a partnership, or as technology improvements change cost structure. None = benefit is not worth the cost or effort. Task ForceAverage RankCostEffectivenessCategoryI.07 Infrastructure Better Maintain Existing System 5.0 $$$$$ high Planning I.08 Infrastructure Control Sources of Clogs 7.3 $$$$$ high Planning E.01 Emergency Services Develop Local Flooding Emergency Response Plan 7.4 $$$ medium Planning I.15 Infrastructure New Storage in Parks 7.6 $$$$$ high Development I.19 Infrastructure Buy Low Homes 8.4 $$$$$ low None I.16 Infrastructure New Storage in Roads 8.4 $$$$$ high Development I.13 Infrastructure Search for System Constraints and Quick Wins 9.0 $$$ high Planning I.10 Infrastructure Reduce Sanitary System Inflow 9.1 $$$$$ medium Ongoing I.24 Infrastructure Flood Storage with Predictive Pumping 9.1 $$$$$ high Development R.08 Regulatory Program Update Plans with Flood Risk 9.3 $$$ low Planning R.03 Regulatory Program Regulate Impervious 9.3 $$$$ low Development I.25 Infrastructure Capital Project Prioritization Framework 9.5 $$ medium Development I.01 Infrastructure Citywide Risk Modeling 9.6 $$$ high Planning R.04 Regulatory Program Require Private Flood Storage 9.8 $$$$ low None E.02 Emergency Services Define and Communicate the Available Services 9.9 $$ medium Quick Win I.09 Infrastructure Reduce Vulnerability of Sanitary Lift Stations 10.0 $$$$$ medium Development I.14 Infrastructure Bigger Pipes 10.0 $$$$$ high Development I.03 Infrastructure Peak Flood Visualization 10.1 $$$ high Planning I.04 Infrastructure Flow Path Visualization 10.3 $$$ high Planning O.08 Outreach and Engagement Develop Flood Intervention Fact Sheets 10.3 $$$ medium Quick Win O.07 Outreach and Engagement Develop Frequently Asked Questions (FAQs)10.5 $$ high Quick Win I.17 Infrastructure Design to a Future Risk Level 10.6 $$$$$ medium Planning I.18 Infrastructure Plan Emergency Overflow Paths 10.6 $$$ high Planning O.01 Outreach and Engagement Build Awareness of Stormwater System 10.6 $$ low Planning I.02 Infrastructure Standardize Failure Analysis 10.6 $$$$ medium Development O.06 Outreach and Engagement Promote Sandbag Service 10.8 $$ high Quick Win O.10 Outreach and Engagement Host Flood Summit 10.8 $$$ medium Development R.02 Regulatory Program Flow Path Review 10.9 $$$ high Planning O.05 Outreach and Engagement Develop a 'What is My Flood Risk?" Map 10.9 $$$ high Quick Win I.05 Infrastructure Predictive Snowmelt Modeling 11.0 $$$ low Development I.06 Infrastructure Active Lake Level Monitoring, Smart Infrastructure Pilot 11.0 $$$$ high Development I.11 Infrastructure Assess Water Supply System Risk 11.0 $$$$ medium Planning I.12 Infrastructure Communicate Risk to Power and Utility Industry 11.0 $$ medium Development I.20 Infrastructure Incentivize Redevelopment of Exposed Structures 11.0 $$$$$ low None R.01 Regulatory Program More Permit Review and Regulation 11.0 $$$ medium Development R.05 Regulatory Program Regulate Development to a Higher Flood Standard 11.0 $$ low Development R.06 Regulatory Program Tiered Stormwater Utility Fee Based on Impervious Cover 11.0 $$$ low Development R.07 Regulatory Program Participate in the Community Rating System 11.0 $$ low Planning O.02 Outreach and Engagement Develop and Communicate Dynamic Flood Threat Indicator 11.0 $$$ low Development O.03 Outreach and Engagement Groundwater Level Viewer 11.0 $$ low Planning O.04 Outreach and Engagement Promote WaterAlert (USGS) Subscriptions 11.0 $ low Quick Win O.09 Outreach and Engagement Provide Stormwater Technical Assistance Grant Program 11.0 $$$ medium Quick Win O.11 Outreach and Engagement Engage With Stakeholders at Time of Capital Investment 11.0 $$ medium Development O.12 Outreach and Engagement Engage Realtors, Developers, Insurers on Local Flood Risk 11.0 $ medium Development ID Sector Activity Name Description Justification/Motivating factors Tradeoffs and Other Considerations Task Force RankCost ScoreStaff Rated Effectiveness ScoreAction CategoryI.01InfrastructureCitywide Risk ModelingCreate a standard method across the city (and potentially across other nearby cities) to analyze the risk and consequence of potential for failure of the entire storm sewer system, pipe by pipe, structure by structure. Additionally, this would include creating a standard method to determine impacts due to failure of a part of the system. Finally, reporting methods (maps, prioritized infrastructure components, etc.) would be standardized so that infrastructure risk in different parts of the city and even nearby cities can be easily compared by staff, residents, and decision-makers.A general understanding of the risk of each part of the storm sewer infrastructure system will be able to help prioritize maintenance and inspection activities. Additionally, failure analysis which is often risk based, is not currently standard and is generally quantified on a case by case basis and by the people involved. Therefore, comparing infrastructure risk in different parts of a city or between cities is quite difficult. The only way to know which parts of the infrastructure system should be prioritized in maintenance, with a finite maintenance crew, is to assess the risk of entire storm sewer system in a standard and comprehensive way. The process of evaluating risk of infrastructure may not lend itself to a process that is general. It may be a process that is so "case by case" that the standardized method may become overly complicated and onerous. TBD $$$ high PlanningI.02InfrastructureStandardize Failure AnalysisCreate a standard process for investigating reported or actual failures after significant events. Post event investigation would survey debris lines for peak flow elevations, review damage, investigate system function using hydrologic models, investigate past maintenance records and report expected and actual system performance.This is an alternative or lead-in to smart infrastructure that allows the organization to build knowledge of system function, and periodically review and plan interventions in operations and maintenance that may lead to better system function.Additional data could sit on the shelf if there is not organizational capacity to review, utilize or react to it.TBD $$$$ medium DevelopmentI.03InfrastructurePeak Flood VisualizationCreate products that visualize and explain the extent of expected flooding during storm events. The various types of products could be paper and/or digital maps, the online water resources web map, Google Earth xml files, or other innovative methods. Creating maps or other visualizations of the potential extent of flooding helps identify the locations throughout the city that are most likely to flood. Additionally, similar to the activity of education and outreach, identifying areas of potential flooding and areas that do not show flooding help the public become aware of instances when the system is not functioning as expected. As the public becomes more aware of flooding throughout the city through these products, the new knowledge can likely motivate more citizens to take part in flood risk reduction efforts when they are aware of the extent of flooding throughout the city. With new flood mapping that is far more extensive than traditional FEMA maps, flood insurance prices and home prices may be affected. Maps alone do not tell the entire story; they cannot explain other flood characteristics such as duration. The public may react to the maps by implementing a fix that doesn't appropriately address the issue, i.e., a resident might plan to place a sandbag wall when the duration of flooding is so long that they might still be exposed to basement flooding from groundwater seepage. Some interpretations of the flood maps from the public may not be accurate. Notes concerning the reliability of the tools must be included (based on a calibrated or uncalibrated model, validated with observed data, etc.). TBD $$$ high Planning ID Sector Activity Name Description Justification/Motivating factors Tradeoffs and Other Considerations Task Force RankCost ScoreStaff Rated Effectiveness ScoreAction CategoryI.04InfrastructureFlow Path VisualizationCreate visual products that explain the routes that water would flow during storm events. The various types of products could be paper and/or digital maps with flow direction arrows, the online water resources web map, Google Earth xml files, animations or videos, or other innovative methods. Creating maps or other visualizations of flood water flow paths helps identify the locations throughout the city that should remain open (no obstructions, no development, no pedestrians, cars, etc.) during a flood. Additionally, similar to the activity of education and outreach, identifying areas where water should be flowing during flooding events helps the public be aware of times when the system is not functioning as expected. Areas that would be emergency overflow areas (EOFs) during a flood can also be improved prior to flooding so that when activated, they do not erode. With new flood mapping that is far more extensive than traditional FEMA maps, flood insurance prices and home prices may be affected. Maps alone do not tell the entire story; they cannot explain other flood characteristics such as duration. Some reactions to the flood maps from the public may not be entirely appropriate. Notes concerning the reliability of the tools must be included (based on a calibrated or uncalibrated model, validated with observed data, etc.). Homeowners who live adjacent to flow paths and/or emergency over flows (EOFs) may take it into their own hands, on their own property, to alter the terrain so that water does not flow adjacent to their home. This may have other adverse consequences on their own or on other people's homes. TBD $$$ high PlanningI.05InfrastructurePredictive Snowmelt ModelingForecasted/predicted snowmelt modeling to help the city better understand spring flood risk.Predictive snowmelt modeling may help city staff and the community better understand spring flood risk. Forecasted high springtime water levels associated increased flood risk may inform flood risk reduction measures by the city (e.g. preparation for emergency pumping, sandbags, etc.), especially for landlocked basins and basins with restricted outlets.While melt can be estimated, it is uncertain due to duration of melt and any intervening rainfalls. This can lead undue alarm or a 'cry-wolf' affect. This effort may be better at a watershed or metro area level. Alternatives include amplifying general messages from the NWS. Existing water levels and snowpack measurements are required to forecast spring water levels. Collecting this information may take considerable staff time; but without this information, the snowmelt modeling may only provide a limited benefit for restricted outlet and landlocked basins.TBD $$$ low DevelopmentI.06InfrastructureActive Lake Level Monitoring, Smart Infrastructure PilotConstruct water level and discharge measurement sensors at key stormwater management system points (i.e. critical lakes, ponds, streams, and pipes).Current water level measurements can be used to monitor flood exposure, and therefore inform flood management activities (i.e. emergency pumping, sandbagging) as well as optimize operation of dynamic stormwater management systems equipped with adjustable weirs and outlets. Inconsistencies between measured data and flood models has led to identification of stormwater infrastructure no longer functioning as intended (i.e. sediment filled pipes, pipes with frost heaves, sediment filled channels, clogged outlets, etc.). Increasing the number of sensors throughout the city would allow for a more widespread system performance evaluation. Sensors can be difficult to maintain and are frequently damaged by adverse weather conditions and vandalism. Discharge monitoring may lead to identification of Inflow and Infiltration (I&I) issues. Data connections could be considered to creek flow gages maintained by watershed districts.The ability to construct and utilize adjustable weirs based on forecasted data may be limited by the DNR. For these additional measurements to be useful, the existing flood models may need to be refined to provide real-time forecasting abilities.TBD $$$$ high Development ID Sector Activity Name Description Justification/Motivating factors Tradeoffs and Other Considerations Task Force RankCost ScoreStaff Rated Effectiveness ScoreAction CategoryI.07InfrastructureBetter Maintain Existing SystemUse a proactive asset management strategy to proactively inspect system to 1) identify infrastructure with relatively minor issues that can be readily repaired, and 2) add operations to remove collected debris and sediment from system trash racks, storm sewer pipes, catch basins, and inlets.Repair and replace stormwater infrastructure before minor issues escalate to costly replacements (inspect concrete pipe cracks, CCTV, stormwater pump head tests, ditch/stream thalweg surveys).Additionally, trash racks, culvert inlets, and storm sewer pipes can be blocked by sediment and debris. Poorly performing infrastructure reduces the overall stormwater infrastructure system efficiency and results in additional flooding/drainage issues. Addressing minor issues may provide water quality benefits. Less complaints from residents and more confidence in the stormwater management system.TBD $$$$$ high PlanningI.08InfrastructureControl Sources of ClogsStreet and flow path debris can clogs and plug stormwater infrastructure. Proactive street sweeping and maintenance of inlets and flow paths can reduce debris sources. Trash racks, culvert inlets, and storm sewer pipes can be blocked by sediment and debris, resulting in additional flooding/drainage issues. Even if partially plugged, additional flooding can occur. To address these sources of clogs and debris, the city could evaluate the benefits of implementing/constructing more stormwater Best Management Practices (BMPs) (i.e. vegetative cover, construction stormwater management, etc.). Addressing the sources of clogs and debris may provide water quality benefits and documentation of these measures may be useful for the Municipal Separate Storm Sewer System (MS4) permit and Stormwater Pollution Prevention Program.Addressing the sources of clogs and debris may also require enforcement, which could adversely impact relationships with private property owners in the city. TBD $$$$$ high PlanningI.09InfrastructureReduce Vulnerability of Sanitary Lift Stations Assess risk, floodproof, raise or relocate sanitary lift stations out of floodplain. For those sanitary lift stations that are low in elevation and within the floodplain, it may be important to elevate the lift station, or move it entirely so that it is no longer in the floodplain.When sanitary lift stations are in the floodplain, they can become unreachable during a significant flood. Additionally, they may become inundated with stormwater. This could cause a problem by allowing stormwater into the sanitary system, overwhelming it with too much flow. Improvements could include raising the electrical and controls systems, floodproofing the hatch, planning for emergency sandbagging and pumping to access, raising a section of the structure, or relocating entirely. Often these features are placed where they are for multiple very good reasons. Moving a lift station is a significant task, especially when space in a well-developed city is hard to come by. And finding another place out of the floodplain that is still as good as the original place (with regard to the other deciding factors) is a difficult task.TBD $$$$$ medium DevelopmentI.10InfrastructureReduce Sanitary System InflowFailures in the sanitary sewer system can cause backup into structures. The long term reduction of sources of infiltration and inflow of surface and groundwaters can incrementally reduce risk.This program is ongoing and associated with the sanitary sewer utility. It is ongoing in standalone projects and the neighborhood and Municipal State Aid (MSA) street reconstruction programs.TBD $$$$$ medium OngoingI.11InfrastructureEvaluate Water Supply System RiskFor those water supply systems (for example, wells) that are low in elevation and within the floodplain, it may be important to elevate the system, or move it entirely so that it is no longer in the floodplain.When water supply systems are in the floodplain, they can become unreachable during a significant flood. Additionally, they may become inundated with stormwater. This could cause a problem by contaminating the water supply system and creating an expensive condition that requires remediation.Often these features are placed where they are for multiple very good reasons. Moving water supply systems is a significant task, especially when space in a well-developed city is hard to come by. And finding another place out of the floodplain that is still as good as the original place (with regard to the other deciding factors) is a difficult task. Often distribution pipes are buried under roads and this would require tearing up roads. TBD $$$$ medium Planning ID Sector Activity Name Description Justification/Motivating factors Tradeoffs and Other Considerations Task Force RankCost ScoreStaff Rated Effectiveness ScoreAction CategoryI.12InfrastructureCommunicate Risk to Power and Utility IndustryMuch like an emergency action plan, or education and outreach, this activity would be providing the proper information to private utility companies (electric, internet, fiber optic, etc.) of the locations and facilities that are most flood prone. Ideally, the activity that publishes flood extent visualizations could feed into this one. Access to buried utilities could be very limited around flood prone facilities. During flood events, driven often by large storm events, electricity could be down in parts of the city. The private utility companies should be aware of the areas and facilities prone to flooding so that they can plan to reduce the vulnerability of exposed systems, or be better prepared to fix elements of their system during and after a storm. This could become a daunting task every time the modeling is updated and the maps are recreated. Additionally, if there are flooding issues and private utilities are down, the city could be blamed or even sued if the private utilities company feels that the provided information was not accurate enough to help them be successful. TBD $$ medium DevelopmentI.13InfrastructureSearch for System Constraints and Quick Wins The stormwater network involves a complex system of overland flow, stormwater pipes, ditches, ponds, basins, and streams to convey stormwater off of the landscape. Using existing models and infrastructure data, identify the isolated and "easy to solve" choke points that may be limiting the overall capacity of the stormwater management system. Significant reductions in flood risk may be achievable in areas with "easy to solve" stand-alone constraints. These "easy to solve" fixes are likely to be significantly less expensive than other comprehensive system changes.Some of these retrofits are likely to be located within stormwater easements on private property (i.e. backyard flooding problems). Replacement/retrofit of the storm sewer in these areas may be disruptive.(Assume this is a desktop review to find these "easy to solve" retrofits and other activities are the construction/implementation for those locations). The effort can be used to inform future project scope and selection to better target resources to flood risk reduction.TBD $$$ high PlanningI.14InfrastructureBigger Pipes Replace undersized storm sewer in specific flood areas in some areas where there are no/limited downstream impacts associated with larger discharge from bigger pipes. Replace undersized storm sewer in specific flood areas to improve discharge away from the site and reduce flooding for areas without concerns of downstream impacts.In many instances, retrofitting bigger pipes is likely to lead to downstream impacts. Furthermore, other governing agencies, such as watershed management organizations or downstream cities, may limit or refuse additional discharge associated with larger pipes because of downstream impacts. There are limited opportunities for this type of risk transfer after the affects of climate change are factored in to an already constrained system.TBD $$$$$ high DevelopmentI.15InfrastructureNew Storage in ParksRetrofit new storage into or under park spaces.There is limited available, open space for construction of stormwater storage. Utilizing the space in or under park spaces is one of the few remaining places for stormwater storage. Increased stormwater storage will reduce downstream discharge and reduce flood risk (impacts) to downstream properties.There will likely resistance from the community to flooded parks and additional resources may be required to convert the park to a multipurpose land use. The addition of new storage may not be applicable everywhere, including sites with limited infiltration capacity, polluted ground, adjacent to wellheads, or with high bedrock. To use park spaces as flood storage, the city will likely need to educate residents about the multipurpose land use and that the park space will be flooded from time to time. The Park and Recreation Department, Park and Recreation Commission, and park users would be stakeholders.Stormwater reuse for irrigation may be an option is some parks.TBD $$$$$ high Development ID Sector Activity Name Description Justification/Motivating factors Tradeoffs and Other Considerations Task Force RankCost ScoreStaff Rated Effectiveness ScoreAction CategoryI.16InfrastructureNew Storage in RoadsRetrofit new stormwater storage into or under roads.There is limited available, open green space for construction of stormwater storage (i.e., a stormwater pond). As roads and parking lots are reconstructed, utilize this space in or under parking lots/roads as one of the few remaining places for stormwater storage. Increased stormwater storage can help reduce downstream discharge and reduce flood risk (impacts) to downstream properties.Flooded roads and parking lots may receive pushback from the community and additional resources may be required to educate residents about where to drive/park during wet periods. The addition of new storage may not be applicable everywhere, including sites with limited infiltration capacity, polluted ground, adjacent to wellheads, or with high bedrock. Furthermore, stormwater storage on roadways is limited by requirements for emergency vehicle access. Storage under roadways is also limited by other buried utilities.TBD $$$$$ high DevelopmentI.17InfrastructureDesign to a Future Risk LevelWhen designing a part of the stormwater infrastructure system, we can no longer rely on using design storm events that are based solely on past observed data. We should be considering what climate forecasting models are telling us, and we should be considering the expected life of the infrastructure.A part of the stormwater infrastructure system that is mean to last 5 years and then no longer function does not necessarily need to be overly concerned with what the climate may be 30 years from now. Additionally, the probability of a 1% annual chance event occurring in the next 5 years is only about 5 percent. On the contrary, a part of the system meanT to be functional for the next 50 years should most certainly be considering the changing climate and the predictions of future large storm events. The probability of a 1% annual chance event occurring in the next 50 years is 40 percent. Given that, the chance of a piece of infrastructure being tested by its design storm during its life depends on the expected life of the infrastructure. And the magnitude of the change in the characteristics of the design storm event also depends on the expected life of the infrastructure. This approach will create even more uncertainty in the design process. In all likelihood, ponds, pipes, structures, weirs, pumps, and all other infrastructure will be designed bigger, potentially uncomfortably big and uncomfortably expensive, if the future climate risk is seriously considered in design. TBD $$$$$ medium PlanningI.18InfrastructurePlan Emergency Overflow PathsPlanning emergency flow paths is the approach of understanding the natural emergency overflows, and then planning to create, maintain, and protect those that exist, that safely pass stormwater flow, and therefore protect people and structures from flooding and harm. Having a prepared understanding of the emergency flow paths, rather than surprise of where stormwater ends up flowing, is beneficial for the protection of infrastructure within the city. Additionally, similar to the activity of publishing visualizations of flow paths, this planning can help understand the function of the system and whether or not it is operating appropriately during large flood events. Some residents may not like where emergency overflows are planned, prepared, maintained and protected. This would impact park uses. There are certainly instances of unplanned overflow locations that will surprise the public, and require study and private or public action to limit exposure. There may be pushback from the public in creating or maintaining these features. Outreach and would be necessary to communicate where these areas are and how park uses may be impacted.TBD $$$ high Planning ID Sector Activity Name Description Justification/Motivating factors Tradeoffs and Other Considerations Task Force RankCost ScoreStaff Rated Effectiveness ScoreAction CategoryI.19InfrastructureBuy Low HomesOffer to purchase homes that are so flood exposed that the cost to protect them from flooding (or significantly reduce their flood exposure) is so high that it is beyond the value of the home. This is much like totaling a car after an accident significant enough that it doesn't even make sense to try and fix the car.The cost of capital projects to protect some homes can be very high, particularly for some homes that are built very low and near bodies of water. The vulnerability can be due to a number of factors and decisions when the home was built. Regardless of the reason for the high vulnerability, the cost to protect homes in this condition is beyond the value of the home itself. Additionally, there may be a cost in emergency rescues for people who live in those homes during flood events. Therefore, buying the home is the most cost-effective solution. Buyouts have been shown to be a cost-saving measure for taxpayers because the damages avoided result in cost savings on both flood insurance and disaster relief.Strategies to reduce vulnerability of these homes to flood can be much more fruitful. Buying out a resident is an emotional process; it may or may not be easy for a person to move, even if it is for their protection and benefit. Often, the cost/benefit for acquisitions makes the most sense on the lowest value homes - it is important to consider offsetting acquisitions with affordable housing options. Removing the vulnerable home will also remove a property/home from the tax base of the city. The loss in tax base may make sense if a 'fix' is considerably more expensive. The city then would have to decide if it is possible to redevelop the site, raise the future structure to limit exposure, or leave it vacant. A vacant site may provide minimal temporary storage. Leaving properties vacant could also increase green space. If state or federal funding is used, it might be deed restricted as open space in perpetuity.TBD $$$$$ low NoneI.20InfrastructureIncentivize Redevelopment of Exposed StructuresThe city can create a program that is available to residents where they can redevelop or reduce the flood risk of their home and be helped financially by the city. A redevelopment project of a home is expensive financially, takes time and effort, can be stressful if the home is inhabitable for a time, and has other factors that make it difficult. Incentives offered by the city can be motivating to a homeowner to help them decide to take action and protect themselves. The incentives can also turn the necessary project from impossible to possible financially. If the voluntary acquisitions are not an option, this approach may be able to reduce flood risk while maintaining, or even improving, the tax base. This process of redevelopment is happening without incentives. Incentives complicate the financial proposition, and involve the city in a process that is atypical and may cause more uncertainty and conflict. Incentives may need to be large to convince a homeowner to take on such a big task. The overall cost of the city depends on the number of homes that they intend to provide aid to, and the number of people willing to join the incentive program. TBD $$$$$ low None ID Sector Activity Name Description Justification/Motivating factors Tradeoffs and Other Considerations Task Force RankCost ScoreStaff Rated Effectiveness ScoreAction CategoryI.24InfrastructureFlood Storage with Predictive PumpingAdd the innovative technology that monitors current conditions, tracks forecasts, models predicted flooding, and operates pumps to respond, to pump stations on water bodies that could benefit from predictive pumping flood risk reduction strategies.Water bodies with passive outlets can only be drawn down to the outlet's invert, or sometimes below with long periods of evaporation and minimal rain. All of the water in the water body is taking up storage that cannot be filled with incoming stormwater. A water body with a pumped outlet could potentially be drawn down further than normal to create the opportunity for added stormwater storage during a flood event. This is a way to create or provide storage without actually creating additional ponds, underground storage, or other types of storage on the landscape. It's simply a way to better utilize the current volume available for storage within the city. This method (predictive pumping) requires good weather forecasts, calibrated models with proven prediction capabilities. This method will likely be a long process of working with the DNR to develop a plan that improves storage capacity for the protection of the people, but also promotes protection of the other living things in and around the water body. Retrofitting predictive pumping will require more than electronics, wiring, and programming logic. It will likely require modifications to pipes on the suction side of the pump to be able to draw the water body down further. Some lift stations are quite small (fitting in the space of a manhole perhaps) and retrofitting this type of capability may require a small box or building on the surface to house the equipment. TBD $$$$$ high DevelopmentI.25InfrastructureDevelop Capital Project Prioritization FrameworkMaximize the effectiveness of limited funds by being deliberate in examining the vulnerability to floods and the greatest sources of possible disruption. Develop a scoring system using cost benefit analysis to identify and prioritize capital projects. The method used should be objective, transparent, and easy for the public to access and understand.Capital projects don't go through a vetting process. Requests are considered without determining how a specific issue ranks in comparison to others with regard to flood exposure, effectiveness, etc.There is a feeling among the Task Force that 'the squeaky wheel gets the grease'.Some project petitioners may find their project doesn't even register when compared to others. Even among Task Force members this would likely be the case.Judging criteria would have to be determined.TBD $$ medium DevelopmentR.01Regulatory ProgramMore Permit Review and RegulationEngineering review for small additions, accessory structures (sheds), impervious expansions not related to a building (deck/patio/etc.). Permits for grading, new homes, and major remodels with footprint changes all include engineering review for flow paths, grading and drainage. Retaining wall, minor remodels, interior remodels, mechanical, and other permit types are not reviewed.Reviewing more permit types may catch additional issues relating to site-to-site, drainage.This program is staff intensive, and would require additional resources for a fairly limited benefit.TBD $$$ medium DevelopmentR.02Regulatory ProgramRegulate Flow PathsInventory overland flow paths. Consider flow paths in permit review process. Make room for and plan for flow where it occurs by grading or armoring flow paths. Divert or limit unplanned flow paths by requiring engineered grading plans during permit review, when serious issue areas are encountered. Some improvements may not be presently triggering a permit review by the Engineering Department. Staff could investigate and identify issue areas, create a comprehensive list, and require private properties to address the risk in design if at the time a permit is applied for on an issue area.Minor addition to staff review process for permits that are already reviewed by Engineering.Minor addition in permits that would trigger a review by Engineering.May limit property owners ability to implement improvements on their property or increase their costs.Policy or code revision may be necessary.TBD $$$ high Planning ID Sector Activity Name Description Justification/Motivating factors Tradeoffs and Other Considerations Task Force RankCost ScoreStaff Rated Effectiveness ScoreAction CategoryR.03Regulatory ProgramRegulate ImperviousImpervious surfaces generate more runoff. Limiting impervious surfaces by changing ordinance can reduce runoff generation.Analysis in task force effort showed this approach is very limited in terms of effectiveness.Major additional cost to some private parties. Moderate addition to staff review process for permits that are already reviewed by Engineering.Moderate addition in permits that would trigger a review by Engineering.May limit property owners ability to implement improvements on their property or increase their costs.Policy or code revision would be necessary.Would increase green space and may promote more trees. Both cost and benefit is highly variable depending on the level of regulation, and if mitigation is allowed. The costs are born by both the public, and private parties, depending on the level of regulation.TBD $$$$ low DevelopmentR.04Regulatory ProgramRequire Private Flood StorageProjects that trigger the regulatory check would be required to store volume on their site.There is a perception that redevelopment is adding volume and contributing to flood impacts. Analysis in task force effort showed this approach is very limited in terms of effectiveness. Current regulatory program manages risk on a permit-by-permit basis for residential, commercial, and industrial sites. Sites larger than one acre in size are required to control stormwater volume under the Construction Stormwater Permit.Major addition to staff review process for permits that are already reviewed by Engineering. Additional design, coaching, and inspection necessary.Post-construction program with inspections necessary.Maintenance agreements or other legal instrument necessary.Enforcement necessary.Will limit property owners ability to implement improvements on their property and will increase their costs.Policy or code revision would be necessary. There are additional costs that would be born by private parties that is not included in the costs score.TBD $$$$ low NoneR.05Regulatory ProgramRegulate Development to a Higher Flood StandardLevel of protection is currently the 1% annual chance (100-year) storm. This would be more restrictive, applying standards for a larger storm event such as the 0.2% annual chance (500-year) storm. (i.e. higher lowest floors and potentially further setback from water).Climate change is a main driver of increased flooding. Future predictions are that flood events will be larger and more frequent. Minor addition to staff review process for permits that are already reviewed by Engineering.Minor addition in permits that would trigger a review by Engineering.May limit property owners ability to implement improvements on their property or increase their costs.Policy or code revision will be necessary.TBD $$ low Development ID Sector Activity Name Description Justification/Motivating factors Tradeoffs and Other Considerations Task Force RankCost ScoreStaff Rated Effectiveness ScoreAction CategoryR.06Regulatory ProgramTier Stormwater Utility Fee Based on Impervious CoverHigh impervious sites pay more. Model site runoff generation and rework the land use x acreage calculations to consider specific impervious of the individual site.Make the polluter pay' concept. Applying penalties for adding impervious may deter those from implementing projects. Staff intensive. Potential for a lot of negotiating back and forth about impervious cover. Would need to consider how residential stormwater BMPs like raingardens, landscaping, permeable pavements, and rain barrels fit it. May require staff intensive site inspections/verifications and annual or biannual updates. Some owners may be willing to 'pay their way out' to still be able to complete their project.TBD $$$ low DevelopmentR.07Regulatory ProgramParticipate in the Community Rating SystemThe City of Edina participates in the National Flood Insurance Program.The National Flood Insurance Program's (NFIP) Community Rating System (CRS) is a voluntary incentive program that recognizes and encourages community floodplain management activities that exceed the minimum NFIP requirements.As a result, flood insurance premium rates are discounted to reflect the reduced flood risk resulting from the community actions.Potential cost savings for those holding policies. Number of policies and staff time required will determine if participation is cost-effective.TBD $$ low PlanningR.08Regulatory ProgramUpdate Plans with Flood RiskRoll the Flood Risk Reduction Strategy and Comprehensive Water Resources Management Plan amendment into the Comprehensive Plan with a major amendment.Promote a citywide vision for flood risk reduction. Need to collaborate with other comp plans and groups such as the Southdale work group and other small area plans.TBD $$$ low PlanningO.01Outreach and EngagementPromote Awareness of Stormwater SystemEducation and outreach to community on the function and importance of the stormwater management system.An education and outreach program will help the community understand the function and importance of the stormwater management system and its role to minimize flooding and manage water quality. Education may improve flooding issues (e.g. improved participation in Adopt-a-Drain), identify stormwater infrastructure that is no longer functioning as designed, and help residents understand multipurpose land use (e.g. flooded parks and soccer fields).Additional understanding of flood risk has the potential to impact property values may reduce some property values. Synergy with MS4 required community education/outreach may limit additional city resources required. Education of the community may also improve water quality (reducing illicit dumping, salt usage, etc.). Staff would utilize customer service standards of integrity, quality, and service to assist residents in accessing available resources.TBD $$ low Planning ID Sector Activity Name Description Justification/Motivating factors Tradeoffs and Other Considerations Task Force RankCost ScoreStaff Rated Effectiveness ScoreAction CategoryO.02Outreach and EngagementDevelop and Communicate Dynamic Flood Threat IndicatorForecast flood threat for design storms and also scenarios such as ice jams, saturated conditions, and snow melt. Host the dynamic indicator online.Perception of flood threat determines action. Would require moderate maintenance effort.Groundwater level and extent is highly uncertain and non-continuous. May provide false sense of security. TBD $$$ low DevelopmentO.03Outreach and EngagementDevelop Groundwater Level ViewerUsers can view relative groundwater level with year over year changes.Flooding risk may increase if shallow groundwater is high and stormwater infiltration is limited.May provide false sense of comfort. Groundwater elevations and extent is extremely variable spatially and temporally. Might be difficult to relate relative groundwater level to an individual basement elevation. Money may be better spent encouraging those at greatest risk to invest in draintile and sump pump systems instead.TBD $$ low PlanningO.04Outreach and EngagementPromote WaterAlert (USGS) SubscriptionsAnyone can sign up for text alerts for available United States Geological Survey (USGS) stream gauge sites.Program already operating. Would be low cost/energy to implement. Changes can be viewed in nearly real-time. Experience may help customers to benchmark their own risk on the hydrograph (water elevation graph).May provide false sense of comfort. Urban streams tend to be flashy (i.e., flow and elevation can increase rapidly).Can add to website Frequently Asked Questions.TBD $ low Quick WinO.05Outreach and EngagementDevelop a 'What is My Flood Risk?" MapComplementary to existing water resources map with the goal of communicating flood risk clearly.Better communication of flood risk. Understanding circumstance is first step in addressing vulnerability and exposure.Concern over impact on property values as community becomes more flood aware.It may be difficult to show the depth of flooding on the map - some may be an inch whereas others may be more than a foot.Some assumptions are made about topography - more detailed surveys on a site by site basis could show structures higher or lower than the model and aerial photo suggest.Concern about accuracy and completeness. Feedback from those that use the map is critical.TBD $$$ high Quick WinO.06Outreach and EngagementPromote Sandbag ServiceCreate series of videos to communicate how to make a request for sandbags and how to build a sandbag wall. Train staff how to receive requests and provide assistance over the phone.Most are unaware of the service. Those that are aware highly value the service.Some property owners and renters may have limited ability to place their own sandbags. Unclear what service provider might do this type of work if it were hired out.Disposal of sandbags post-event.Staff would need to be trained on how to receive requests and provide assistance over the phone.TBD $$ high Quick Win ID Sector Activity Name Description Justification/Motivating factors Tradeoffs and Other Considerations Task Force RankCost ScoreStaff Rated Effectiveness ScoreAction CategoryO.07Outreach and EngagementDevelop Frequently Asked Questions (FAQs)Available on the City website. A resource for reception staff to direct customers to.Would help to debunk myths. Help people self-serve the information. More immediate access to information versus calling a staff person, although always an option.Occasional review and minor edits would be needed. Need to inform staff that the resource is available to share with customers. Standard customer service standards of integrity, quality, and service apply.TBD $$ high Quick WinO.08Outreach and EngagementDevelop Flood Intervention Fact SheetsDevelop Fact Sheets for common interventions that property owners and renters could implement to reduce their exposure and vulnerability to flooding. Interventions may be pre, mid, or post storm. Fact sheets would provide a description, general cost information, and appropriate applications. Examples include floodproofing, elevating utilities, flood insurance, sanitary backflow prevention, sandbagging, among others. Some feedback suggests that the interactive water resources map in its current form requires technical expertise to interpret. Changes to the interactive map would make the flood risk information more accessible.A potential barrier to reducing one’s own exposure to flooding may be their perceived ability (knowledge, skills, and resources) to take action. Other barriers, such as cost may limit a property owner or renter's ability to implement.Renters may have limited ability to implement strategies.Considerations ought to be made for all residential structures, not just single dwelling units.Fact sheets may be used by sellers to show how structures are less exposed/vulnerable.TBD $$$ medium Quick WinO.09Outreach and EngagementProvide Stormwater Technical Assistance Grant ProgramPilot year completed in 2019. Competitive grants help pay for technical evaluation of an issue affecting a resident’s property. A report documents understanding of the problem and lays out a potential plan that could then be implemented by the property owner, at their cost. Some technical assistance can increase the perceived ability (expertise, knowledge, resources) for an individual to help themselves. Case studies may be useful to others in similar situations.Grant covers design, up to a cap. Grant does not cover implementation.Reformat to cover more, from 1:1 to presentation and future design consultations.This could be like a mini flood summit.$20,000/yr existing funding.Would need to ensure the program is attractive to applicants.TBD $$$ medium Quick WinO.10Outreach and EngagementHost Flood SummitDirect mail invitations to at-risk properties. Get all stakeholders together including representatives from neighborhoods, insurance, emergency service professionals, county, police and fire, landscapers, home service providers, MN DNR, engagement professionals, decision-makers, Watershed Districts, infrastructure experts, neighboring cities. All share and discuss roles and approaches for a changing climate with increasing flood risk.Incorporates various approaches involved in reducing exposure, increasing resilience to changing risks, transformation, reducing vulnerability, transferring and sharing risks, and preparing, responding, and recovering.Would require major staff effort and coordination of other parties. Would be a pilot. Unaware of a local model to follow or existing process/program to leverage.Consider equity when selecting a pilot community.TBD $$$ medium Development ID Sector Activity Name Description Justification/Motivating factors Tradeoffs and Other Considerations Task Force RankCost ScoreStaff Rated Effectiveness ScoreAction CategoryO.11Outreach and EngagementEngage with Stakeholders at Time of Capital InvestmentIncorporate into public improvements such as street reconstruction and park improvement projects. Develop custom engagement plans as appropriate.Incorporate into public improvements such as street reconstruction and park improvement projects. Develop custom engagement plans as appropriate.Opportunities to address problem areas may lie outside of the public improvement project boundaries.Some solutions may require private property cooperation in the form of easements, agreements, and assessments.This is a long term strategy driven by private and public investment.TBD $$ medium DevelopmentO.12Outreach and EngagementEngage with Realtors, Developers, and Insurance Agents on Local Flood RiskHost a class to inform realtors, developers, and insurance agents on local flood risk. Presentation materials could be hosted online or made into a brief video.As more stakeholders understand flood risk, there will likely be a market effect.As more stakeholders understand flood risk, there may be a market effect.Desire for residents and property owners to be engaged first.Information must be accurate, current, and easy to understand.TBD $ medium DevelopmentE.01Emergency ServicesDevelop Local Flooding Emergency Response PlanSource flood threat information and predict flood threat.Define affected areas/parties and frontline communities.Develop warning system.Develop emergency response plan.Establish public information program.Develop maintenance and improvement program.Coordinate with other departments/agencies.A hazard response plan exists for major disasters only.Customers expect a higher level of service and response than the current major disaster response plan provides.The perceived flood threat likely influences property owner/renter behavior.The plan should consider frontline communities and vulnerability. Developing a plan based on historical service requests alone is not an equitable approach.This strategy doesn't effect the flood, but instead effects the preparation for and recovery after a disaster. Damages may be reduced and a return to normalcy may happen more rapidly.Would require setting a trigger condition.Opportunity to consider better protections for frontline communities.TBD $$$ medium PlanningE.02Emergency ServicesDefine and Communicate the Available ServicesInfo about what the City can and can’t do about active flooding; explanation of how the City prioritizes flood-related requests for service posted to City website. Call center training and emergency response plan inclusion. There is a gap between the status quo service level and customer expectations. Better defining available services may motivate property owners and renters to take actions to reduce their own exposure.Potential equity disparity if service delivery is driven by requests for service only. Have a plan for engaging with frontline communities, reaching out rather than only waiting for a request for service.TBD $$ medium Quick Win Flood Risk Reduction –Draft Strategy Review City Council and task force work session March 4, 2020 Task Force Framework Strategy Examples at 4 scales of action PAST to FUTURE Next steps EdinaMN.gov 2 Outline Members / Introductions •12 Meetings, 9 months Value to Staff •Gaps; Service expectations vs. reality •Value and values •Shared language •Common problem, leading the conversation EdinaMN.gov 3 Task Force Technical analysis What is valuable, when? What matters, where, to whom? What is flooding? How we view risk Drivers of increasing flood risk Areas of work EdinaMN.gov 4 Framework Surface water Groundwater Sanitary backflow Pathways to structural flood risk EdinaMN.gov 5 EdinaMN.gov 6 Climate / Natural Environment Varies in time •Short term weather •mid-term season •long term climate Varies in place •Uphill / slopes / low area •Near creek, wetland, lake How we view risk 7 Flood Exposure •Degree to which property, homes, buildings, infrastructure and other asset come into contact with flood water •Depends on runoff, flow, storage, drainage, groundwater, and soils. Varies spatially, some area near low areas and flow paths are exposed How we view risk EdinaMN.gov 8 Flood Vulnerability •The degree to which exposed assets are unable to resist flooding and are damaged by floods •Depends on the extent of assets on the land, both public and private, and how well it can resist flooding, or limit damage when flooded How we view risk EdinaMN.gov 9 How we view risk Key equation Flood risk = climate x exposure x vulnerability Applied at varying scales; system, class, component City Example: Sanitary system, sanitary sewer lift station, electrical components Personal Example: Dwelling, foundation/basement, individual window well EdinaMN.gov 10 Areas of Work Technical analysis / quick wins •Infrastructure •Regulation •Emergency Services •Outreach and Engagement Task Force Discussions •What we expect vs. what we get and future vision •Shared view of risk, what we value and personal values •Potential actions / prioritization EdinaMN.gov 11 Drivers of increasing risk Leading drivers TOP –Climate change has already, and will expose more assets to flooding in the future. This driver is predicted to overwhelm the other drivers in terms of scale. SECOND –Private and public asset and infrastructure are both exposed and vulnerable. Public infrastructure can define flood exposure for different points in the landscape, and serve as a pathway for private risk EdinaMN.gov 12 Drivers of increasing risk Other drivers THIRD –Most of the land use decisions have already been made, and cannot be unmade, we choose to drain the landscape, connect it to the waters, and develop over waters. There is additional demand for drainage that can reduce vulnerability, but marginally affects flood exposure downstream. FOURTH –There is increasing demand for use of land, imperviousness drives runoff in small storms and marginally affects flood exposure in large storms How we view risk Areas of work Drivers of increasing flood risk EdinaMN.gov 13 Framework Comprehensively reduce the risk of flooding throughout the community In our work with the community we will; •make flood information available to all and promote flood awareness •work to help people stay safe in floods •help people protect their properties from flooding and the affects of floods •plan public streets and parks to accept and transmit flood waters to reduce the risk and disruption of related city services EdinaMN.gov 14 Strategy Comprehensively reduce the risk of flooding throughout the community In our areas of work; •Infrastructure: We will renew our infrastructure and operate it to reduce risk •Regulation: We acknowledge competing demands of land use and addressing drainage, groundwater and surface water issues. We help people solve issues without harming another •Outreach and engagement: We make flood information available and give people tools for flood resilience •Emergency Services: We help people prepare for floods, remove people from harm during floods, and recover after floods. EdinaMN.gov 15 Strategy 16 FUTURE How we view risk •Systems, awareness, dynamic •Climate x exposure x vulnerability Areas of work •Infrastructure, regulation, outreach & engagement, emergency services •Risk management Key Trends •Climate change, aging infrastructure PAST How we view risk •Reactive, static •probability x consequence Areas of work •Infrastructure and emergency response •Bigger pipes, risk transfers, rescue Key Trends •Drainage, land development EdinaMN.gov 17 Framework FUTURE •Freeways shut down, sewers back up, flooded basements, less? •Staff reallocated to call center, provide safety advice only •Emergency response plan brings resources to problems faster •Predictive pumping make a little extra room based on forecasts •Capital plan is proactive and prioritized, no need for reactive change PAST •Freeways shut down, sewer backups, flooded basements •Call center overwhelmed •After action, look to blame, solve ‘problem areas’ that flooded by transferring risk downstream EdinaMN.gov 18 ’87 style flood response FUTURE •Add storage in streets and right of way (lower streets, tree trenches, etc) •Add new curb and gutter, plan emergency flow paths •Rebuild catch basins, add needed inlets •Review pipe sizes, repair and upsize only where we make room with storage downstream PAST •Add new sump drainage pipe •Add new curb and gutter •Rebuild catch basins Neighborhood and parks reconstruction EdinaMN.gov 19 FUTURE •Erosion and stormwater standards •Regional and local flood elevation standards, grading and drainage review •Impervious limit •Technical assistance available •People are flood aware, help others •People with exposure have taken actions to reduce vulnerability •Most critical at-risk structures removed or redeveloped PAST •Erosion control standards •Regional flood elevation standards •No impervious limit •No technical assistance Residential redevelopment, individual home drainage issue EdinaMN.gov 20 FUTURE •once per five year proactive inspection and preventative maintenance •Preventative debris removal •Adopt-a-drain, community cleanups •Enhanced street sweeping •Trouble spot retrofits •Smart infrastructure, remote level awareness, predictive pumping control PAST •Reactive maintenance, run-to-failure •Clear clogs •2 per year street sweeping Stormwater infrastructure, operations and maintenance EdinaMN.gov 21 FUTURE •Risk Management •Comprehensive areas, service based •Policy and program •Adaptation, design for future based on increasing risk of climate change •Community focus, build capacity for resilience •$xx.xx? PAST •Problem solving •Focus area, complaint based •Reactive •Design for past, assume future looks the same •Expert focused, technical •Storm Utility fee $37.59/quarter EdinaMN.gov 22 Water resources paradigm Indirect •Impervious Surface Planning Commission Proposal •Climate Action Plan •2020-21 Budget workplan •2021-26 Capital Improvement Plan (CIP) •2022-23 Budget Direct •Finalize framework and strategy for Council consideration •Order major amendment to Comprehensive Water Resources Management Plan, align policy with strategy and do tactical planning for water resource program expansion •Create first comprehensive flood risk reduction plan with public engagement ahead of Morningside 2022-23 reconstruction projects and Weber park development EdinaMN.gov 23 Next Steps