Terrapin Lake
Washington County, MinnesotaView mapDirections
Minnesota PCA publishes the water-quality measurements for Terrapin Lake. Here is what has been measured.
- 41 ft max depth
- Limited data
Terrapin Lake in Washington County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 9.7 ft visibility.
Terrapin Lake is a lake in Washington County, Minnesota with an estimated average depth of about 41 feet. Limited fish-species data available. No public access — the lake is private or restricted.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-08-27. Methodology: how these readings are compared.
What Terrapin Lake is good for
From access and monitoring records, not editorial picks.
- Ice seasonIce-out around Mar 20
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Terrapin 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 Terrapin Lake
These are the measurements Minnesota PCA publishes for Terrapin Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Moderate clarity, visible to about 9.7 ft. TSI 44.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 9.7ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. | |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 44 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Terrapin Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Terrapin Lake typically sits around 52°F at the surface in October. Summer average is about 72°F. Usually warmest in Aug (about 74°F) and coldest in Apr (about 49°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (49°F) to its warmest (74°F).
Typical surface water temperature by month, from 90 field readings (2011–2019) via the EPA Water Quality Portal. See the full Terrapin Lake water temperature breakdown →
Lake Details
Max depth
~41 ft est.
Public access
No
Listed by Minnesota PCA
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Minnesota has not published bathymetry for Terrapin Lake.
Lake Size & Watershed
Watershed (drainage) area
1 sq mi
HydroLAKES / HydroSHEDS
Surface area
116 acres
HydroLAKES / HydroSHEDS
Shoreline
3 mi
HydroLAKES / HydroSHEDS
Elevation
909 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Stays via Stay22
Stays near Terrapin Lake
Compare lakeside cabins, hotels, and vacation rentals near Terrapin 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 Terrapin 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 Terrapin Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fishing Terrapin Lake
Ice season
Typical ice-out
Mar 20
Earliest Mar 19, 2012 · Latest Apr 3, 2009
Most recent ice-out
Mar 19
2012
4 observations · Minnesota PCA ice records
Nearby Lakes in Washington County
Frequently asked questions about Terrapin Lake
Where is Terrapin Lake?
- Terrapin 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 Terrapin Lake?
- Terrapin Lake in Washington County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 9.7 ft visibility.
Is Terrapin Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Terrapin Lake?
- Terrapin Lake typically sits around 52°F at the surface in October, from 90 EPA Water Quality Portal field readings (2011–2019). That is a typical value for the month, not a live reading.
How deep is Terrapin Lake?
- No published bathymetric survey covers Terrapin Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 41 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
When does Terrapin Lake thaw?
- Terrapin Lake typically has ice-out around Mar 20.
Can I fish at Terrapin Lake?
- Public access to Terrapin Lake is listed as no on the lake record, so confirm before you make the trip. 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 Terrapin 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
More lakes in Minnesota
State Parks Near Terrapin Lake
Other Lakes in Minnesota
Mesotrophic Lakes in Minnesota
Where this data comes from
3 measurements from 1 monitoring station, 2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA3 samples · 2024
Analytical methods
- Field measurement/observation, generic method
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Ice data from Minnesota DNR Climate