Borah Lake
Richland County, IllinoisView mapDirections
Illinois EPA publishes the water-quality measurements for Borah Lake. Here is what has been measured.
- Eutrophic
- Impaired · Mercury
- 31 ft max depth
- Public access
- Limited data
Borah Lake in Richland County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Water clarity: 2.2 ft visibility. Phosphorus: 153.5 µg/L. Chlorophyll-a (algae): 29 µg/L.
Borah Lake is a productive, nutrient-rich eutrophic lake in Richland County, Illinois with an estimated average depth of about 31 feet. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 2 other monitored lakes in Richland County, Borah Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, Illinois EPA, last sampled 2022-10-13. Methodology: how these readings are compared.
What Borah 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. Borah Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Borah 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 Borah Lake
These are the measurements Illinois EPA publishes for Borah 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 2.2 ft of visibility. Phosphorus 153.5 µg/L. Chlorophyll-a 29 µg/L. TSI 69.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 2.2ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 154µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 29µg/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. | 69 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Borah Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Borah Lake typically sits around 61°F at the surface in October. Summer average is about 77°F. Usually warmest in Aug (about 79°F) and coldest in Apr (about 55°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (55°F) to its warmest (79°F).
Typical surface water temperature by month, from 209 field readings (2014–2022) via the EPA Water Quality Portal. See the full Borah Lake water temperature breakdown →
Lake Details
Max depth
~31 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 Borah Lake.
Lake Size & Watershed
Watershed (drainage) area
4 sq mi
HydroLAKES / HydroSHEDS
Surface area
104 acres
HydroLAKES / HydroSHEDS
Shoreline
3.8 mi
HydroLAKES / HydroSHEDS
Elevation
476 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
- Borah LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Borah Lake
Compare lakeside cabins, hotels, and vacation rentals near Borah Lake in Richland 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 Borah Lake are listed below.
Top-rated places to stay near Borah 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 Borah Lake → · more Illinois lake trips
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Fishing Borah Lake
Reservoir Info (USACE NID)
Borah Lake is a man-made reservoir impounded by the M. D. Borah Lake Dam (completed 1953), built primarily for recreation on the TRIB FOX RIVER; earth-type dam, 36 ft tall and 960 ft long.
- Normal storage
- 2,060 ac-ft
- Max storage
- 4,720 ac-ft
- Hazard class
- High
- Owner
- CITY OF OLNEY
All listed purposes: Recreation;Water Supply.
Source: USACE National Inventory of Dams, NID ID IL00331 · Operator website · Matched by proximity (0.87 km)
EPA Impairment Status
Borah 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_RCB · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Borah Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- West Liberty - Dundas Sanitary District StpDundas · 4.1 mi away · NPDES IL0077879Recent violation
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 Richland County
Frequently asked questions about Borah Lake
Where is Borah Lake?
- Borah Lake is a lake in Richland County, Illinois. Its water-quality measurements are published by Illinois EPA and shown on this page as reported.
What is the water quality of Borah Lake?
- Borah Lake in Richland County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Water clarity: 2.2 ft visibility. Phosphorus: 153.5 µg/L. Chlorophyll-a (algae): 29 µg/L.
Is Borah Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Borah Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
What is the water temperature of Borah Lake?
- Borah Lake typically sits around 61°F at the surface in October, from 209 EPA Water Quality Portal field readings (2014–2022). That is a typical value for the month, not a live reading.
How deep is Borah Lake?
- No published bathymetric survey covers Borah Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 31 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 Borah Lake?
- Borah Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Borah Lake. Public access is listed as yes.
Can I fish at Borah Lake?
- Borah 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 Borah Lake across LakeQuality
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Where this data comes from
42 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_WQX42 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)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Named boat-access points from the USGS National Boat Ramps inventory