Nashville City Lake
Washington County, Illinois52 acresView mapDirections
Illinois EPA publishes the water-quality measurements for Nashville City Lake. Here is what has been measured.
- Hypereutrophic
- Impaired · Mercury
- Limited data
Nashville City Lake in Washington County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Water clarity: 1.3 ft visibility. Phosphorus: 606 µg/L. Chlorophyll-a (algae): 89.3 µg/L. Surface area: 52 acres.
Nashville City Lake is a 52-acre highly nutrient-loaded hypereutrophic lake in Washington County, Illinois.
Source: EPA Water Quality Portal sampling records, Illinois EPA, last sampled 2022-10-11. Methodology: how these readings are compared.
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. Nashville City Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, nutrients (phosphorus, nitrogen), pesticides. Check local advisories before you swim.
Whether Nashville City 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 Nashville City Lake
These are the measurements Illinois EPA publishes for Nashville City 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 1.3 ft of visibility. Phosphorus 606 µg/L. Chlorophyll-a 89.3 µg/L. TSI 81.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 1.3ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 606µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 89.3µg/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. | 81 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Nashville City Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Nashville City Lake typically sits around 60°F at the surface in October. Summer average is about 84°F. Usually warmest in Jul (about 85°F) and coldest in Oct (about 60°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (60°F) to its warmest (85°F).
Typical surface water temperature by month, from 197 field readings (2012–2022) via the EPA Water Quality Portal. See the full Nashville City Lake water temperature breakdown →
Lake Details
Surface area
52 acres
No bathymetric survey has been published for Nashville City Lake, so its depth is not documented here.
Stays via Stay22
Stays near Nashville City Lake
Compare lakeside cabins, hotels, and vacation rentals near Nashville City Lake in Washington 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 Nashville City Lake are listed below.
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Fishing Nashville City Lake
Reservoir Info (USACE NID)
Nashville City Lake is a man-made reservoir impounded by the Nashville City Reservoir Dam (completed 1935), built primarily for recreation on the TRIB NASHVILLE CREEK; earth-type dam, 26 ft tall and 740 ft long.
- Surface area
- 52 ac
- Normal storage
- 400 ac-ft
- Max storage
- 701 ac-ft
- Drainage area
- 1.4 sq mi
- Hazard class
- High
- Owner
- CITY OF NASHVILLE
All listed purposes: Recreation;Water Supply.
Source: USACE National Inventory of Dams, NID ID IL00138 · Operator website
EPA Impairment Status
Nashville City 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: Drinking water, Fish consumption, Other.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit IL_ROO · Official waterbody report
Regulated Pollution Sources Nearby
5 EPA-permitted facilities operate within about 5 miles of Nashville City Lake under Clean Water Act (NPDES) discharge permits. 3 facilities have a reported Clean Water Act violation in the past three years.
- New Minden Stp, Village OfNashville · 1.6 mi away · NPDES IL0041335Recent violation
- Nashville Stp, City OfNashville · 1.7 mi away · NPDES IL0027081Recent violation
- Washington County Conservation Area -StpNashville · 4.4 mi away · NPDES IL0048577Recent violation
- Nashville Wtp, City OfNashville · 0.2 mi away · NPDES IL0069701
- Nascote Industries, Inc.Nashville · 1.3 mi away · NPDES IL0068136
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
Nearby Lakes in Washington County
Frequently asked questions about Nashville City Lake
Where is Nashville City Lake?
- Nashville City Lake is a lake in Washington County, Illinois. Its water-quality measurements are published by Illinois EPA and shown on this page as reported.
What is the water quality of Nashville City Lake?
- Nashville City Lake in Washington County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Water clarity: 1.3 ft visibility. Phosphorus: 606 µg/L. Chlorophyll-a (algae): 89.3 µg/L. Surface area: 52 acres.
Is Nashville City Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Nashville City Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, nutrients (phosphorus, nitrogen), pesticides. Check local advisories before you swim.
What is the water temperature of Nashville City Lake?
- Nashville City Lake typically sits around 60°F at the surface in October, from 197 EPA Water Quality Portal field readings (2012–2022). That is a typical value for the month, not a live reading.
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Where this data comes from
48 measurements from 3 monitoring stations, 2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- illinois epa
IL_EPA_WQX48 samples · 2022
Analytical methods
- MEASURED IN FIELD
- Phosphorus by Colorimetry
- 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
Monitoring station identifiers (3)
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)