Marie Lake
Lake County, IllinoisView mapDirections
Illinois EPA publishes the water-quality measurements for Marie Lake. Here is what has been measured.
- Hypereutrophic
- Impaired · Mercury
- 49 ft max depth
- Limited data
Marie Lake in Lake County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Water clarity: 2.7 ft visibility. Phosphorus: 76 µg/L. Chlorophyll-a (algae): 55 µg/L.
Marie Lake is a highly nutrient-loaded hypereutrophic lake in Lake County, Illinois with an estimated average depth of about 49 feet. Public access is available with 1 public boat landing. Compared to the 18 other monitored lakes in Lake County, Marie Lake ranks #14 for water quality.
Source: EPA Water Quality Portal sampling records, Illinois EPA, last sampled 2022-10-25. Methodology: how these readings are compared.
What Marie Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
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. Marie Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, nutrients (phosphorus, nitrogen), pCBs. Check local advisories before you swim.
Whether Marie Lake is safe to swim in today is a call for the Illinois Environmental Protection Agency and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Marie Lake
These are the measurements Illinois EPA publishes for Marie Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 2.7 ft of visibility. Phosphorus 76 µg/L. Chlorophyll-a 55 µg/L. TSI 66.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 2.7ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 76µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 55µg/L | Poor GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 66 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Marie Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Marie Lake typically sits around 58°F at the surface in October. Summer average is about 77°F. Usually warmest in Jul (about 81°F) and coldest in Oct (about 58°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (58°F) to its warmest (81°F).
Typical surface water temperature by month, from 244 field readings (2012–2022) via the EPA Water Quality Portal. See the full Marie Lake water temperature breakdown →
Lake Details
Max depth
~49 ft est.
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Illinois has not published bathymetry for Marie Lake.
Lake Size & Watershed
Watershed (drainage) area
17 sq mi
HydroLAKES / HydroSHEDS
Surface area
492 acres
HydroLAKES / HydroSHEDS
Shoreline
5.7 mi
HydroLAKES / HydroSHEDS
Elevation
728 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.
Recreation & Access
- Chain O' LakesSemi-private
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Marie Lake
Compare lakeside cabins, hotels, and vacation rentals near Marie Lake in Lake County, Illinois — 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. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Marie Lake are listed below.
Top-rated places to stay near Marie Lake
Prices for Oct 30–Nov 1, 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 trip? Cabins and lodging at Marie Lake → · more Illinois lake trips
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Fishing Marie Lake
Reservoir Info (USACE NID)
Marie Lake is a man-made reservoir impounded by the Coopers Farm Sediment Storage Dam, built primarily for debris control on the LAKE MARIE - OFFSTREAM; earth-type dam, 13 ft tall and 2,500 ft long.
- Normal storage
- 0 ac-ft
- Max storage
- 6 ac-ft
- Drainage area
- 0.1 sq mi
- Hazard class
- High
- Owner
- ILLINOIS DEPARTMENT OF NATURAL RESOURCES
Source: USACE National Inventory of Dams, NID ID IL55139 · Operator website · Matched by proximity (0.96 km)
EPA Impairment Status
Marie Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Fish consumption, Other.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit IL_RTR · Official waterbody report
Nearby Lakes in Lake County
Frequently asked questions about Marie Lake
Where is Marie Lake?
- Marie Lake is a lake in Lake County, Illinois. Its water-quality measurements are published by Illinois EPA and shown on this page as reported.
What is the water quality of Marie Lake?
- Marie Lake in Lake County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Water clarity: 2.7 ft visibility. Phosphorus: 76 µg/L. Chlorophyll-a (algae): 55 µg/L.
Is Marie Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Marie Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, nutrients (phosphorus, nitrogen), pCBs. Check local advisories before you swim.
What is the water temperature of Marie Lake?
- Marie Lake typically sits around 58°F at the surface in October, from 244 EPA Water Quality Portal field readings (2012–2022). That is a typical value for the month, not a live reading.
How deep is Marie Lake?
- No published bathymetric survey covers Marie Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 49 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Are there boat ramps on Marie Lake?
- Marie Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Chain O' Lakes.
Can I fish at Marie Lake?
- Marie 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 Illinois's fish and wildlife agency, so check its current regulations before you go.
Explore Marie Lake across LakeQuality
Species activity outlook by water temperature and season
Top lakes and where to stay in the Chain O'Lakes area
Where to stay at Illinois's top lakes, each with its readings
Illinois's cleanest lakes, ranked on agency measurements
More lakes in Illinois
Other Lakes in Illinois
Hypereutrophic Lakes in Illinois
Where this data comes from
22 measurements from 2 monitoring stations, 2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- illinois epa
IL_EPA_WQX22 samples · 2022
Analytical methods
- MEASURED IN FIELD
- Phosphorus by Colorimetry
- 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
Monitoring station identifiers (2)
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Named boat-access points from the USGS National Boat Ramps inventory