Lake Jefferson
Lake Jefferson in Le Sueur County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 4 ft visibility. Maximum depth: 37 ft. Surface area: 684.57 acres.
Minnesota DNR surveys at Lake Jefferson average 18.16 black crappie per unit of sampling effort (CPUE) across 12 surveys. The most recent is a Standard Survey dated July 29, 2024. Length samples in the latest survey that recorded them ran 4–12 inches. DNR survey details →
- Clarity
- 4 ft
- Typical in August
- 79°F
- Max depth
- 37 ft
- Area
- 685 acres
- Trend
- ↑ Improving
- Public access
- Yes
- Ice-out
- Apr 6
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Why Lake Jefferson has no grade
We grade a lake only when the monitoring record supports a letter: 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 Lake Jefferson, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. 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.
Lake Jefferson is a 685-acre lake in Le Sueur County, Minnesota with a maximum depth of 37 feet. Overall water quality is improving over recent sampling years. The lake supports 18 documented fish species including bigmouth buffalo, black bullhead, and black crappie. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-07-28. Grade methodology: LakeQuality 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 Lake Jefferson
These readings exist but are not enough for an A–F grade — see why.
Murky, only visible to about 4 ft. Trophic State Index: 57.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 57 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Lake Jefferson
Compare lakeside cabins, hotels, and vacation rentals near Lake Jefferson in Le Sueur 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 Lake Jefferson
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Planning a whole trip? See where to stay at Minnesota’s top lakes →
Water Temperature
Lake Jefferson typically sits around 79°F at the surface in August. Summer average is about 72°F. Usually warmest in Aug (about 79°F) and coldest in May (about 59°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 27 field readings (2010–2025) via the EPA Water Quality Portal. See the full Lake Jefferson water temperature breakdown →
Minnesota DNR surveys at Lake Jefferson average 18.16 black crappie per unit of sampling effort (CPUE) across 12 surveys. The most recent is a Standard Survey dated July 29, 2024. Length samples in the latest survey that recorded them ran 4–12 inches.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality does not assign an A–F grade on Lake Jefferson — official chemistry is on file, not a letter, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
12 surveys on file from MN DNR Fisheries. Most recent: 2024-07-29 (Standard Survey).
Top Species by Catch Rate
| Species | Avg catch rate (CPUE) | Avg Weight |
|---|---|---|
| Black Bullhead | 60.68 | 0.64 lb |
| Black Crappie | 18.16 | 0.22 lb |
| Yellow Perch | 18.12 | 0.15 lb |
| Bluegill | 17.50 | 0.17 lb |
| Common Carp | 6.49 | 3.47 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE means more abundant in standardized sampling. This 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.
Black Bullhead
Black Crappie
Yellow Perch
Bluegill
From the 2024-07-29 survey
East Jefferson Lake is a 700-acre lake located approximately 4.5 miles southeast of the town of Cleveland in Le Sueur County. A DNR-maintained public access is located on the east side of the lake off Beaver Dam Road. The maximum depth is 37 feet with 48% of the lake less than 15 feet deep. East Jefferson Lake has…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Lake Jefferson. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — East JeffersonFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — East JeffersonFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — East JeffersonPublic Water Access Sites · MN DNR LakeFinder
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 37 ft |
| Surface Area | 685 acres |
| Shoreline Length | 5.9 mi |
| Littoral Zone | 50% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Jefferson Lake (East)Public
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Lake Jefferson
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
Water Quality Trend: ↑ Improving
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.194 m/yr | 6 |
| Phosphorus | ↑ Improving | -10.54 µg/L/yr | 3 |
| Chlorophyll-a | ↑ Improving | -6.99 µg/L/yr | 3 |
Ice Season
Historical ice data from Minnesota DNR (3 observations).
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2016-03-12 (2016) | 2023-04-12 (2023) |
Most recent ice-out: 2023-04-12
Reservoir Info (USACE NID)
Lake Jefferson is a man-made reservoir impounded by the Lake Jefferson (completed 1938), built primarily for recreation on the BIG CANNON RIVER - TR; gravity-type dam, 9 ft tall and 15 ft long.
- Surface area
- 700 ac
- Normal storage
- 18,544 ac-ft
- Max storage
- 25,489 ac-ft
- Drainage area
- 16.3 sq mi
- Hazard class
- Low
- Owner
- MNDNR-Trails
Source: USACE National Inventory of Dams, NID ID MN00155 · Operator website
EPA Impairment Status
Lake Jefferson 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 MN40-0092-01 · Official waterbody report · Matched by proximity (0.37 km)
Graded lakes near Lake Jefferson
Lake Jefferson has no grade, but these lakes within a short drive do.
Nearby Lakes in Le Sueur County
Frequently asked questions about Lake Jefferson
Where is Lake Jefferson?
- Lake Jefferson is a lake in Le Sueur County, Minnesota. LakeQuality has not rated this lake (UNRATED) — there is not enough recent sampling to assign a letter.
What is the water quality grade for Lake Jefferson?
- Lake Jefferson in Le Sueur County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 4 ft visibility. Maximum depth: 37 ft. Surface area: 684.57 acres.
Is Lake Jefferson safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Lake Jefferson is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
What is the water temperature of Lake Jefferson?
- Lake Jefferson typically sits around 79°F at the surface in August, from 27 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Lake Jefferson?
- Lake Jefferson has a maximum depth of 37 feet. The lake covers 684.57 acres.
What fish are in Lake Jefferson?
- Fish species found in Lake Jefferson include bigmouth buffalo, black bullhead, black crappie, bluegill, bowfin (dogfish), common carp, freshwater drum, green sunfish, hybrid sunfish, largemouth bass, longnose gar, northern pike, pumpkinseed, walleye, white bass, white crappie, yellow bullhead, yellow perch. Lake Jefferson is located in Le Sueur County, Minnesota.
What did the DNR fisheries survey find at Lake Jefferson?
- Minnesota DNR surveys at Lake Jefferson average 18.16 black crappie per unit of sampling effort (CPUE) across 12 surveys. The most recent is a Standard Survey dated July 29, 2024. Length samples in the latest survey that recorded them ran 4–12 inches. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality does not assign an A–F grade on Lake Jefferson — official chemistry is on file, not a letter, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
When does Lake Jefferson thaw?
- Lake Jefferson typically has ice-out around Apr 6.
Are there boat ramps on Lake Jefferson?
- Lake Jefferson has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Jefferson Lake (East). Public access is listed as yes.
Explore Lake Jefferson across LakeQuality
Depth, room, public access, and the state wake-sport rules
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Fish species and best lakes in Le Sueur County
Species activity outlook by water temperature and season
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Where this data comes from
12 measurements from 1 monitoring station, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- North American Lake Management Society
NALMS12 samples · 2020–2024
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
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