Rush Lake
Rush Lake in Otter Tail County, Minnesota has a water quality grade of C (Fair). Water clarity: 7.5 ft visibility. Phosphorus: 27 µg/L. Chlorophyll-a (algae): 9.8 µg/L. Maximum depth: 68 ft. Surface area: 5275.68 acres.
- Clarity
- 7.5 ft
- Typical in August
- 74°F
- Max depth
- 68 ft
- Area
- 5,276 acres
- Type
- Eutrophic
- Trend
- ↑ Improving
- Public access
- Yes
- Ice-out
- Apr 14
Next lake in Otter Tail County
Free interactive depth-contour map of Rush Lake, reaching a maximum surveyed depth of 65 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.
Rush Lake is a 5,276-acre productive, nutrient-rich eutrophic lake in Otter Tail County, Minnesota with a maximum depth of 68 feet. Water quality is graded C based on 2 sampling years through 2025. Overall water quality is improving over recent sampling years. The lake supports 19 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing. Compared to the 65 other monitored lakes in Otter Tail County, Rush Lake ranks #58 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-24. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyModerate
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
Moderate clarity, visible to about 7.5 ft. Phosphorus level: 27 µg/L. Chlorophyll-a: 9.8 µg/L. Trophic State Index: 51.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 7.5 ft | Not graded |
| Phosphorus | 27 µg/L | Fair |
| Chlorophyll-a (Algae) | 9.8 µg/L | Fair |
| Trophic State Index (TSI) | 51 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Rush Lake
Compare lakeside cabins, hotels, and vacation rentals near Rush Lake in Otter Tail 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 Rush Lake
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Water Temperature
Rush Lake typically sits around 74°F at the surface in August. Summer average is about 73°F. Usually warmest in Jul (about 75°F) and coldest in May (about 54°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 145 field readings (2010–2025) via the EPA Water Quality Portal. See the full Rush Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 68 ft |
| Surface Area | 5,276 acres |
| Shoreline Length | 13.6 mi |
| Littoral Zone | 63% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Rush Lake (East)Public
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Rush Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
DNR Fisheries Survey Summary
15 surveys on file from MN DNR Fisheries. Most recent: 2025-08-11 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluntnose Minnow | 32.02 | — |
| LGP | 30.52 | — |
| Yellow Perch | 21.89 | 0.12 lb |
| MMS | 16.89 | — |
| Bluegill | 12.19 | 0.16 lb |
| Spottail Shiner | 9.84 | — |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
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.
Yellow Perch
Bluegill
From the 2025-08-11 survey
Rush Lake is 5,337-acre mesotrophic (moderately fertile) lake located in central Otter Tail County two miles north of Ottertail, MN. Rush Lake is part of the Otter Tail River Watershed. The Otter Tail River inlet is located along the north shoreline while the outlet is located along the southwest shoreline of the…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Rush Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — RushFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — RushFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — RushPublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.043 m/yr | 6 |
| Phosphorus | ↑ Improving | -1.97 µg/L/yr | 6 |
| Chlorophyll-a | → Stable | -0.17 µg/L/yr | 6 |
Ice Season
Historical ice data from Minnesota DNR (8 observations).
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2012-03-21 (2012) | 2022-05-06 (2022) |
Most recent ice-out: 2023-05-03
Reservoir Info (USACE NID)
Rush Lake is a man-made reservoir impounded by the Rush Lake (completed 1937), built primarily for recreation on the Otter Tail River; gravity-type dam, 8 ft tall and 105 ft long.
- Surface area
- 5,233 ac
- Normal storage
- 52,330 ac-ft
- Max storage
- 78,345 ac-ft
- Drainage area
- 669.6 sq mi
- Hazard class
- Low
- Owner
- MNDNR-EWR
Source: USACE National Inventory of Dams, NID ID MN00211 · Operator website
EPA Impairment Status
Rush Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN56-0141-00 · Official waterbody report
County Ranking
Ranked #58 of 66 lakes in Otter Tail County
Nearby Lakes With Higher Grades
Rush Lake holds Grade C. 3 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Otter Tail County
Frequently asked questions about Rush Lake
What is the water quality grade for Rush Lake?
- Rush Lake in Otter Tail County, Minnesota has a water quality grade of C (Fair). Water clarity: 7.5 ft visibility. Phosphorus: 27 µg/L. Chlorophyll-a (algae): 9.8 µg/L. Maximum depth: 68 ft. Surface area: 5275.68 acres.
Is Rush Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Rush Lake has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 9.8 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Rush Lake?
- Rush Lake typically sits around 74°F at the surface in August, from 145 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Rush Lake?
- Rush Lake has a maximum depth of 68 feet. The lake covers 5275.68 acres.
What fish are in Rush Lake?
- Fish species found in Rush Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, common carp, green sunfish, hybrid sunfish, lake sturgeon, largemouth bass, northern pike, pumpkinseed, rock bass, shorthead redhorse, tullibee (cisco), walleye, white sucker, yellow bullhead, yellow perch. Rush Lake is located in Otter Tail County, Minnesota.
When does Rush Lake thaw?
- Rush Lake typically has ice-out around Apr 14.
Are there boat ramps on Rush Lake?
- Rush Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Rush Lake (East). Public access is listed as yes.
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Where this data comes from
197 measurements from 3 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA197 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (3)
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
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory
Ice data from Minnesota DNR Climate