Lily Lake
Washington County, Minnesota44 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Lily Lake. Here is what has been measured.
- Mesotrophic
- Impaired · Mercury
- 51 ft max depth
- Public access
- Limited data
Lily Lake in Washington County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 10.5 ft visibility. Phosphorus: 17 µg/L. Chlorophyll-a (algae): 5.1 µg/L. Maximum depth: 51 ft. Surface area: 43.79 acres.
Minnesota DNR's Standard Survey on June 7, 2021 caught 2.00 northern pike per gill net at Lily Lake. DNR survey details →
Lily Lake is a 44-acre mesotrophic lake in Washington County, Minnesota with a maximum depth of 51 feet (18-foot average). The lake supports 10 documented fish species including black crappie, bluegill, and green sunfish. Public access is available with 1 public boat landing. Compared to the 74 other monitored lakes in Washington County, Lily Lake ranks #8 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-23. Methodology: how these readings are compared.
Lily Lake covers about 44 acres in Washington County. It has one public boat landing. Vrbo is where to look for cabins and lake homes around Lily Lake, and Booking.com and Expedia search hotels near the lake for your dates.
What Lily Lake is good for
From access and monitoring records, not editorial picks.
- Clear water10.5 ft of visibility
- Boat launch1 documented ramp
- Fishing10 species recorded
- Deep water51 ft surveyed max depth
Swimming conditions
Readings onlyLimited data
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Lily Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Whether Lily Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Lily Lake
These are the measurements Minnesota PCA publishes for Lily Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 10.5 ft. Phosphorus 17 µg/L. Chlorophyll-a 5.1 µg/L. TSI 45.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 10.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 17µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 5.1µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 45 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Lily Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Lily Lake typically sits around 49°F at the surface in October. Summer average is about 53°F. Usually warmest in Sep (about 56°F) and coldest in Feb (about 37°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (37°F) to its warmest (56°F).
Typical surface water temperature by month, from 425 field readings (2010–2025) via the EPA Water Quality Portal. See the full Lily Lake water temperature breakdown →
Minnesota DNR's Standard Survey on June 7, 2021 caught 2.00 northern pike per gill net at Lily Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Lily Lake’s water-quality measurements separately, and the water-quality trend over 4 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
10 surveys on file from MN DNR Fisheries. Most recent: 2021-06-07 (Standard Survey).
10 surveys on file · most recent 2021-06-07 (Standard Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluegill | 44.93 | 3–8 in 2021-06-07 | 0.11 lb |
| Largemouth Bass | 12.09 | 6–15 in 2021-06-07 | 0.9 lb |
| Hybrid Sunfish | 6.53 | 6–8 in 2021-06-07 | 0.17 lb |
| Black Bullhead | 5.66 | 7–18 in 2011-06-27 | 0.56 lb |
| Pumpkinseed | 4.24 | 4–6 in 2021-06-07 | 0.12 lb |
| Yellow Perch | 3.83 | 5 in 2021-06-07 | 0.12 lb |
CPUE = catch per unit effort, fish caught per net per set in a standardised survey. It measures abundance, not size, and is not a weekly bite report.
Length Distributions
Number of fish caught at each inch class in the most recent survey that recorded lengths. Red dashed line marks an approximate trophy threshold for that species.
Bluegill
Largemouth Bass
Hybrid Sunfish
Black Bullhead
From the 2021-06-07 survey
Lily Lake is a 36 acre lake located in the City of Stillwater, Washington County. It has a littoral area of 19.7 acres, is in lake class 30, and has approximately one mile of shoreline with nearly 25% owned by the City of Stillwater and managed for recreational use. Lily Lake Park has a fishing pier, boat access…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Lily Lake. 2 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — LilyFisheries Lake Survey · MN DNR LakeFinder
- —Public Water Access Sites — LilyPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
51 ft
Average depth
17.7 ft
Surface area
44 acres
Shoreline
1.1 mi
Littoral zone
45%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
1 sq mi
HydroLAKES / HydroSHEDS
Elevation
840 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Lily LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Lily Lake
Compare lakeside cabins, hotels, and vacation rentals near Lily Lake in Washington County, Minnesota — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
Top-rated places to stay near Lily Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Minnesota’s top lakes →
Follow Lily Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Lily Lake
Water Quality Trend: Stable
Based on 4 years of monitoring (2021–2025).
Water clarity
Stable4 years
EPA Impairment Status
Lily Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Fish consumption.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN82-0023-00 · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Lily Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger.
- Met Council - St Croix Valley WwtpOak Park Heights · 1.7 mi away · NPDES MN0029998Major
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
Nearby Lakes in Washington County
Frequently asked questions about Lily Lake
Where is Lily Lake?
- Lily Lake is a lake in Washington County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Lily Lake?
- Lily Lake in Washington County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 10.5 ft visibility. Phosphorus: 17 µg/L. Chlorophyll-a (algae): 5.1 µg/L. Maximum depth: 51 ft. Surface area: 43.79 acres.
Is Lily Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Lily Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
What is the water temperature of Lily Lake?
- Lily Lake typically sits around 49°F at the surface in October, from 425 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Lily Lake?
- Lily Lake has a maximum depth of 51 feet and an average depth of 17.7 feet. The lake covers 43.79 acres.
What fish are in Lily Lake?
- Fish species found in Lily Lake include black crappie, bluegill, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, walleye, white sucker, yellow perch. Lily Lake is located in Washington County, Minnesota.
What did the DNR fisheries survey find at Lily Lake?
- Minnesota DNR's Standard Survey on June 7, 2021 caught 2.00 northern pike per gill net at Lily Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Lily Lake’s water-quality measurements separately, and the water-quality trend over 4 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Lily Lake?
- Lily Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Lily Lake. Public access is listed as yes.
Can I fish at Lily Lake?
- Lily Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Minnesota's fish and wildlife agency, so check its current regulations before you go.
Explore Lily Lake across LakeQuality
Fish species and the cleanest lakes across Minnesota
Fish species and best lakes in Washington County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the St. Croix Watershed, ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
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State Parks Near Lily Lake
Other Lakes in Minnesota
Mesotrophic Lakes in Minnesota
Where this data comes from
65 measurements from 1 monitoring station, 2021–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA65 samples · 2021–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- Analysis of Chlorophyll in Periphyton and Plankton
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory