HomeMy WebLinkAbout191217 TF Staff Report
December 17, 2019
Flood Risk Reduction Strategy Task Force
Ross Bintner, P.E., Engineering Services Manager
Flood Risk Reduction Strategy - Meeting 11
Introduction
This draft is meant to further define the framework, and to inform a prioritization exercise of a variety of
possible actions that fall under four main sectors of work that can be used in developing the flood risk
reduction strategy. This outline will be further refined, and combined with analysis and background created
as part of the October 15, 2019 Staff Report for the City Council check-in, to create the final staff report
for the flood risk reduction strategy effort.
Framework
Climate change is the lead driver of increasing flood risk in Edina. Flooding caused by extreme rainfall is the
primary hazard related to climate change that we are studying. Risk is defined by the extreme precipitation
events, public and private assets, or systems that are exposed and vulnerable to it. Flood risk reduction
actions will increase resilience by reducing exposure and vulnerability and may use resilience and adaptation
strategies. Climate mitigation actions will reduce the rate of change of future hazards.
The following definitions have been created specifically for this effort, but were influenced by several IPCC
reports for understanding the components of risk and actions to reduce risk, and a modified definition for
flooding was based on the FEMA definition.
Definitions
Flood: A general and temporary condition of partial or complete inundation of normally dry land areas
from: The overflow of ponds, lakes, wetlands or creeks; The overflow, rapid accumulation or runoff of
surface waters from any source; The overflow of surface waters along planned or unplanned paths; Floods
that inundate flood areas or floodplains and flow along emergency overflow paths.
Floodplain or flood area: Areas of land, classified as local or regional that are inundated in a certain
reference storm condition; Emergency overflow paths, planned or unplanned, that may experience surface
flow in reference storm conditions, based on topography.
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Flood Risk: Flood risk is a function of flood probability, flood exposure, and flood vulnerability.
Flood Probability (annual): The annual chance that a flood of any given magnitude will occur. Flood
probability is influenced by hydrologic and hydraulic conditions upstream of any point of interest, and
precipitation probability.
Flood Exposure: The property, structures, infrastructure, and other assets that are exposed to floods.
Flood Vulnerability: The degree to which exposed assets are unable to resist floods and are damaged by
floods.
Flood risk reduction: Actions that reduce or transfer and mitigate risk by: Reducing exposure to floods,
reducing the vulnerability of any asset, or system to the effects of a flood, or reducing flood probability in
one area and transferring it to another area while mitigating the transferred risk.
Resilience: The ability of a social or ecological system to absorb disturbances while retaining the same basic
structure and ways of functioning, the capacity of self-organization, and the capacity to adapt to stress and
change.
Adaptation: The process of adjustment to actual or expected climate and its effects. In human
systems, adaptation seeks to moderate or avoid harm, or exploit beneficial opportunities.
Customer Focus / Expected Service Statements
Staff heard the following sentiments from the Task Force;
Flooding affects quality of life by disrupting daily activities, risking safety, and damaging structures.
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.
Sectors 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.
1. Infrastructure (meeting 2 topic)
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
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the 2018 City of Edina Comprehensive Plan and Comprehensive Water Resources Management
Plan.
Who does the work; Public Works Department, Engineering Department, private redevelopment,
contractors, property owners.
Who is involved; Planning Department, Building Department, 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.
2. Regulatory program (meeting 5 topic)
What is the outcome; New 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.
3. Engagement and outreach (meeting 6 topic)
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, 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.
4. Emergency services (meeting 6 topic)
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.
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Who does the work; Police Department, Fire Department, Engineering Department, Public
Works Department, County/State/Federal Emergency Responders, other infrastructure owners,
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 to rushed planning. A request or complaint-based response may not provide an
equitable distribution of services.
Possible Actions for Each Sector
A series of actions were proposed for a possible menu or toolbox of actions as a result of discussions with
the Task Force. These were formatted into individual Action Sheets that provide detailed descriptions,
justification/motivating factors, tradeoffs and other considerations, cost score, staff ranked effectiveness
score, and action category. These Action Sheets will be used to prioritize and categorize possible elements
of the flood risk reduction strategy. An objective of the December 17th 2019 Task Force meeting will be to
have the Task Force prioritize actions that they perceive to have community support. These rankings as well
as the discussion during the process will inform the next Staff Report to Council.
Prioritization Criteria and Categorization
Each of the possible actions will be evaluated then ranked and scored by the Task Force and staff based on
community enthusiasm, cost, and effectiveness.
Staff have provided a cost score and effectiveness score. The Task Force will perform ranking of actions
based on community enthusiasm, informed by community held positions and interests.
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 is asked to rank each action item in terms of community enthusiasm. Enthusiasm is
the community’s interest or approval of the action and will be ranked on a scale as follows; not at all
enthusiastic, slightly enthusiastic, fairly enthusiastic, and very enthusiastic.
A. Community enthusiasm (positions and interests), Task Force ranked.
Considers
o Tradeoffs
o Community impacts
o Land, other services
o Sustainability goals
o Environmental outcomes
o Social outcomes
Rank from 1-4
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o not at all enthusiastic (1)
o slightly enthusiastic (2)
o fairly enthusiastic (3)
o very enthusiastic (4)
B. Cost, 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+
C. Effectiveness (and confidence), staff scored.
At reducing community vulnerability to flood
At reducing community exposure to flood
At reducing community share of climate change drivers
Categorize based on composite scores
Staff will categorize possible actions based on their composite scores.
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.
Forming a Flood Risk Reduction Strategy
The strategy should include these elements;
1. A clear description of the intended service and how it is valued by the public.
2. A framework for how to understand flood risk, and actions that reduce that risk.
3. A clear description of the major challenges and trends that counter the intended service.
4. The areas of work in which we provide the intended service.
5. A description of the resources we use to do the work.
The follow on, CWRMP major amendment will include tactical choices, and redefine how we deliver related
water resource management services.
The staff report will describe a framework for the strategy, and provide;
An analysis on the service and expected service gaps.
Examples of how to reformulate and redirect existing resources.
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Prioritized areas of work for possible funding.
Examples of the resources use to provide the current service including budget and capital
improvements.
How the next steps relate to programmatic and capital improvement areas, and the choice to be
made.
Possible Next Steps / Schedule;
12/17/19 - prioritization exercise
First quarter 2020 - Finalize staff and Task Force reports
First quarter 2020 – Draft scope for the Comprehensive Water Resources Management Plan major
amendment, Morningside roadway reconstruction preliminary design, and Community Engagement
Plans for both
Late first quarter 2020 – Final Council Work session with the Task Force (tentative March 3rd)
Early second quarter 2020 – Council Meeting
Consider authorizing CWRMP amendment scope
Consider authorizing Morningside roadway reconstruction concept and preliminary engineering
for 2022-23 capital improvements, as well as community engagement plan