HomeMy WebLinkAbout2026 June Indianhead Lake POI Survey Report2026 Indianhead Lake (DOW: 2700400, Hennepin County)
Aquatic Vegetation Point Intercept Survey Report
6/26/2026
An aquatic vegetation point intercept survey was completed in Indianhead Lake on 6/14/2026 for
the City of Edina. The point intercept survey consisted of 100 points. The purpose of the survey was
to inventory aquatic vegetation species during the summer growing season in June. A second
survey will be completed in August. At each site depth was recorded and vegetation was sampled
with a double-sided rake. For every species sampled, an abundance rating was assigned based on
how much was sampled on the rake. The ratings are as follows:
0. Plant species absent
1. Plant species covers <25% of the rake
2. Plant species covers 25-75% of the rake
3. Plant species covers >75% of the rake
This rating scale was taken out of the Minnesota Department of Natural Resources Guidance for
Delineating Aquatic Plants for Management.
Eight species of vegetation were sampled during the survey in 2026 with the most abundance
species being Chara spp (98%), followed by small pondweed (64%). Curlyleaf pondweed was
sampled at 11% of the sites, however, it was sampled at low abundance. Perhaps this could be
used for next year’s curlyleaf pondweed treatment. Leafy pondweed was misidentifled during the
spring curlyleaf pondweed survey, due to the lack of growth. Long fiowering stem and glands were
present during this survey to help ID it as small pondweed. See table 1 for full species list.
Table 1. 2026 June Indianhead Lake aquatic vegetation species list, frequency of occurrence, and average rake
abundance
Species # of
Sites
Frequency of Occurrence
(%)
Average Rake
Abundance Figure #
American Lotus 1 1 1.00 Figure 7
Arrowhead 1 1 1.00 Not Mapped
Chara 98 98 2.82 Figure 4
Coontail 1 1 1.00 Figure 6
Curlyleaf Pondweed 11 11 1.00 Figure 3
Small Duckweed 2 2 1.00 Not Mapped
Small Pondweed 64 64 1.73 Figure 5
Watermeal 1 1 2.00 Not Mapped
Survey metrics were used to calculate Index of Biological Integrity scores for vegetation richness
and fioristic quality index. Both metrics were below the state standards for shallow lakes (Table 2).
Table 2. June 2026 survey IBI metric results compared to the state standard
Metric 2026 Edina Score Shallow Lake Standard
Richness 8 11
Floristic Quality Index 13.08 17.8
Below is a series of maps of Indianhead Lake site richness (Figure 1), overall site abundance (Figure
2), and individual plant species distribution and abundance. Submerged and large fioating species
are mapped. Small fioating and emergent species were not mapped.
Figure 1. June 2026 Indianhead Lake Site Richness. Minimum richness was 0 at only 2 sites and maximum richness was 5.
Figure 2. June 2026 Indianhead Lake Overall Site Abundance. 92% of sites had a rating of 3.
Figure 3: June 2026 Indianhead Lake curlyleaf pondweed distribution and abundance
Figure 4: June 2026 Indianhead Lake Chara distribution and abundance
Figure 5: June 2026 Indianhead Lake small pondweed distribution and abundance
Figure 6: June 2026 Indianhead Lake coontail distribution and abundance. Coontail was only found near the northwest
inlet.
Figure 7: June 2026 Indianhead Lake American Lotus distribution and abundance.