Louise Lake
Lake County, IllinoisView mapDirections
Illinois EPA publishes the water-quality measurements for Louise Lake. Here is what has been measured.
- Hypereutrophic
- Impaired · Nutrients (phosphorus, nitrogen)
- 40 ft max depth
- Limited data
Ask about Louise Lake
Answers come straight from the public measurements and survey records on this page.
Louise Lake in Lake County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Chlorophyll-a (algae): 80.2 µg/L.
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Stays near Louise Lake
Compare lakeside cabins, hotels, and vacation rentals near Louise 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 Louise Lake are listed below.
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Louise Lake is a highly nutrient-loaded hypereutrophic lake in Lake County, Illinois with an estimated average depth of about 40 feet. Compared to the 18 other monitored lakes in Lake County, Louise Lake ranks #18 for water quality.
Source: EPA Water Quality Portal sampling records, Illinois EPA, last sampled 2020-08-13. Grade methodology: LakeQuality methodology.
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. Louise Lake is listed impaired under Clean Water Act §303(d) (IR 5) for nutrients (phosphorus, nitrogen), turbidity. Check local advisories before you swim.
Whether Louise 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 Louise Lake
These are the measurements Illinois EPA publishes for Louise Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data. Chlorophyll-a 80.2 µg/L. TSI 74.
| Metric | Value | EPA condition class |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | 80.2 µg/L | Poor |
| Trophic State Index (TSI) | 74 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~40 ft est. |
| Average Depth | ~7 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 Louise 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 Louise Lake
EPA Impairment Status
Louise Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit IL_VTZJ · Official waterbody report
Nearby Lakes in Lake County
Frequently asked questions about Louise Lake
Where is Louise Lake?
- Louise 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 Louise Lake?
- Louise Lake in Lake County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Chlorophyll-a (algae): 80.2 µg/L.
Is Louise Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Louise Lake is listed impaired under Clean Water Act §303(d) (IR 5) for nutrients (phosphorus, nitrogen), turbidity. Check local advisories before you swim.
How deep is Louise Lake?
- No published bathymetric survey covers Louise Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 40 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
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Where this data comes from
8 measurements from 1 monitoring station, 2020. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- illinois epa
IL_EPA_WQX8 samples · 2020
Analytical methods
- 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
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
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)