Highland Silver Lake
Madison County, IllinoisView mapDirections
Illinois EPA publishes the water-quality measurements for Highland Silver Lake. Here is what has been measured.
- Hypereutrophic
- 49 ft max depth
- Public access
- Limited data
Highland Silver Lake in Madison County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Water clarity: 1.3 ft visibility. Phosphorus: 123 µg/L. Chlorophyll-a (algae): 57.3 µg/L.
Highland Silver Lake is a highly nutrient-loaded hypereutrophic lake in Madison County, Illinois with an estimated average depth of about 49 feet. Limited fish-species data available. Public access is available. Compared to the 1 other monitored lakes in Madison County, Highland Silver Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Illinois EPA, last sampled 2022-10-26. 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. Check local advisories before you swim.
Whether Highland Silver 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 Highland Silver Lake
These are the measurements Illinois EPA publishes for Highland Silver 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 123 µg/L. Chlorophyll-a 57.3 µg/L. TSI 72.
| 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 | 123µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 57.3µg/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. | 72 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Highland Silver Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Highland Silver Lake typically sits around 66°F at the surface in October. Summer average is about 82°F. Usually warmest in Jul (about 85°F) and coldest in Apr (about 63°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (63°F) to its warmest (85°F).
Typical surface water temperature by month, from 36 field readings (2014–2022) via the EPA Water Quality Portal. See the full Highland Silver Lake water temperature breakdown →
Lake Details
Max depth
~49 ft est.
Public access
Yes
Listed by Illinois EPA
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Illinois has not published bathymetry for Highland Silver Lake.
Lake Size & Watershed
Watershed (drainage) area
49 sq mi
HydroLAKES / HydroSHEDS
Surface area
526 acres
HydroLAKES / HydroSHEDS
Shoreline
8.7 mi
HydroLAKES / HydroSHEDS
Elevation
509 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.
Stays via Stay22
Stays near Highland Silver Lake
Compare lakeside cabins, hotels, and vacation rentals near Highland Silver Lake in Madison 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 Highland Silver Lake are listed below.
Top-rated places to stay near Highland Silver Lake
Prices for Oct 23–25, 4 adults. Change dates on the map below.
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Fishing Highland Silver Lake
Reservoir Info (USACE NID)
Highland Silver Lake is a man-made reservoir impounded by the Silver Lake Dam (completed 1962), built primarily for water supply on the EAST FORK SILVER CREEK; earth-type dam, 29 ft tall and 2,780 ft long.
- Normal storage
- 4,224 ac-ft
- Max storage
- 9,945 ac-ft
- Hazard class
- Significant
- Owner
- CITY OF HIGHLAND
Source: USACE National Inventory of Dams, NID ID IL00178 · Operator website
Regulated Pollution Sources Nearby
3 EPA-permitted facilities operate within about 5 miles of Highland Silver Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger. 1 facility has a reported Clean Water Act violation in the past three years.
- Highland Stp, City OfHighland · 4.9 mi away · NPDES IL0029173MajorRecent violation
- Munie Trucking Co.-HighlandHighland · 1.7 mi away · NPDES IL0068861
- Transcanada Keystone Pipeline, L.P.Wood River · 2.1 mi away · NPDES IL0078956
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 Madison County
Frequently asked questions about Highland Silver Lake
Where is Highland Silver Lake?
- Highland Silver Lake is a lake in Madison County, Illinois. Its water-quality measurements are published by Illinois EPA and shown on this page as reported.
What is the water quality of Highland Silver Lake?
- Highland Silver Lake in Madison County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Water clarity: 1.3 ft visibility. Phosphorus: 123 µg/L. Chlorophyll-a (algae): 57.3 µg/L.
Is Highland Silver Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Highland Silver Lake?
- Highland Silver Lake typically sits around 66°F at the surface in October, from 36 EPA Water Quality Portal field readings (2014–2022). That is a typical value for the month, not a live reading.
How deep is Highland Silver Lake?
- No published bathymetric survey covers Highland Silver 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.
Can I fish at Highland Silver Lake?
- Public access to Highland Silver Lake is listed as yes on the lake record. 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 Highland Silver Lake across LakeQuality
Planning a trip around Gateway Arch?
Highland Silver Lake is about 30 miles from Gateway Arch National Park. Crowds there swing hard by season, so the month you pick changes both how busy the park is and what lodging costs.
Best time to visit Gateway Arch →More lakes in Illinois
Other Lakes in Illinois
Hypereutrophic Lakes in Illinois
Where this data comes from
40 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_WQX40 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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)