Timm Lake
Timm Lake in Yellow Medicine County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 2 ft visibility. Surface area: 260 acres.
- Clarity
- 2 ft
- Mean depth
- ~8 ft est.
- Area
- 260 acres
- Public access
- Yes
Next lake in Yellow Medicine County
Why Timm Lake has no grade
We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Timm Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). Sampling here has recorded water clarity, but not phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by MPCA and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Timm Lake is a 260-acre lake in Yellow Medicine County, Minnesota with an estimated average depth of about 8 feet. Limited fish-species data available. Public access is available.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2022-06-25. Grade methodology: LakeGrade methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Timm Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Very murky, less than 2 ft of visibility. Trophic State Index: 67.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 67 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Timm Lake
Compare lakeside cabins, hotels, and vacation rentals near Timm Lake in Yellow Medicine 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 Timm Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Average Depth | ~8 ft est. |
| Surface Area | 260 acres |
| Public Access | Yes |
Depth marked “est.” is a modeled estimate from HydroLAKES, not a measured survey. Minnesota has not published bathymetry for Timm Lake.
Lake Size & Watershed
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.
Fishing Timm Lake
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Timm Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Public Water Access Sites — TimmPublic Water Access Sites · MN DNR LakeFinder
Reservoir Info (USACE NID)
Timm Lake is a man-made reservoir impounded by the Timm Lake (completed 1924), built primarily for other on the Wood Lake Creek; gravity-type dam, 8 ft tall.
- Surface area
- 260 ac
- Normal storage
- 240 ac-ft
- Max storage
- 720 ac-ft
- Drainage area
- 2.99 sq mi
- Hazard class
- Low
- Owner
- County of Yellow Medicine
Source: USACE National Inventory of Dams, NID ID MN00153 · Operator website
Graded lakes near Timm Lake
Timm Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Yellow Medicine County
Frequently asked questions about Timm Lake
What is the water quality grade for Timm Lake?
- Timm Lake in Yellow Medicine County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 2 ft visibility. Surface area: 260 acres.
Is Timm Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Timm Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
How deep is Timm Lake?
- No published bathymetric survey covers Timm Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 8 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate. The lake covers 260 acres.
Explore Timm Lake across LakeGrade
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Where this data comes from
2 measurements from 1 monitoring station, 2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA2 samples · 2022
Analytical methods
- Field measurement/observation, generic method
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder