Lou Yaeger Lake
Montgomery County, Illinois1,410 acresView mapDirections
Nutrients and algae run well above the regional average.
- Hypereutrophic
- Impaired · Mercury
- #2 of 2 in the county
- Public access
- Limited data
Lou Yaeger Lake in Montgomery County, Illinois has a water quality grade of F (Algae-prone). Water clarity: 1.8 ft visibility. Phosphorus: 255 µg/L. Chlorophyll-a (algae): 72.6 µg/L. Surface area: 1410 acres.
- Clarity
- 1.8 ft
- Typical in September
- 70°F
- Area
- 1,410 acres
- Type
- Hypereutrophic
- Phosphorus
- 255 µg/L
- Chlorophyll-a
- 72.6 µg/L
- Public access
- Yes
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Stays near Lou Yaeger Lake
Compare lakeside cabins, hotels, and vacation rentals near Lou Yaeger Lake in Montgomery 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 grade measures nutrients and algae, not lodging — cabins and rentals around Lou Yaeger Lake are listed below.
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Lou Yaeger Lake is a 1,410-acre highly nutrient-loaded hypereutrophic lake in Montgomery County, Illinois. Water quality is graded F based on 2 sampling years through 2022. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 1 other monitored lakes in Montgomery County, Lou Yaeger Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Illinois EPA, last sampled 2022-10-17. Grade methodology: LakeQuality methodology.
What Lou Yaeger Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Big water1,410 acres
Swimming Safety
Grade onlyLimited data
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
The F is nutrients and algae, not a swimming clearance. Lou Yaeger Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, nutrients (phosphorus, nitrogen), turbidity. Check local advisories before you swim.
Water Quality Grade: F (Algae-prone)
Very murky, less than 1.8 ft of visibility. Phosphorus 255 µg/L. Chlorophyll-a 72.6 µg/L. TSI 75. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.8 ft | Not graded |
| Phosphorus | 255 µg/L | Poor |
| Chlorophyll-a (Algae) | 72.6 µg/L | Poor |
| Trophic State Index (TSI) | 75 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Water Temperature
Lou Yaeger Lake typically sits around 70°F at the surface in September. Summer average is about 79°F. Usually warmest in Jul (about 84°F) and coldest in Oct (about 59°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 87 field readings (2012–2022) via the EPA Water Quality Portal. See the full Lou Yaeger Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 1,410 acres |
| Public Access | Yes |
No bathymetric survey has been published for Lou Yaeger Lake, so its depth is not documented here.
Recreation & Access
- Lou Yaeger LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Lou Yaeger Lake
Reservoir Info (USACE NID)
Lou Yaeger Lake is a man-made reservoir impounded by the Lake Lou Yaeger Dam (completed 1966), built primarily for recreation on the WEST FORK SHOAL CREEK; earth-type dam, 54 ft tall and 1,270 ft long.
- Surface area
- 1,410 ac
- Normal storage
- 15,380 ac-ft
- Max storage
- 44,430 ac-ft
- Drainage area
- 104 sq mi
- Hazard class
- High
- Owner
- CITY OF LITCHFIELD
All listed purposes: Recreation;Water Supply.
Source: USACE National Inventory of Dams, NID ID IL00693 · Operator website
EPA Impairment Status
Lou Yaeger 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_RON · Official waterbody report
Regulated Pollution Sources Nearby
4 EPA-permitted facilities operate within about 5 miles of Lou Yaeger Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger. 3 facilities have a reported Clean Water Act violation in the past three years.
- Litchfield StpLitchfield · 4.9 mi away · NPDES IL0020621MajorRecent violation
- Litchfield - Yeager Lake Stp, City OfLitchfield · 2.3 mi away · NPDES IL0054976Recent violation
- Litchfield-Hillsboro LandfillLitchfield · 2.8 mi away · NPDES IL0075728Recent violation
- Litchfield Wtp, City OfLitchfield · 2.6 mi away · NPDES IL0059153
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.
County Ranking
Ranked #2 of 2 lakes in Montgomery County
Nearby Lakes in Montgomery County
Frequently asked questions about Lou Yaeger Lake
Where is Lou Yaeger Lake?
- Lou Yaeger Lake is a lake in Montgomery County, Illinois. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Lou Yaeger Lake?
- Lou Yaeger Lake in Montgomery County, Illinois has a water quality grade of F (Algae-prone). Water clarity: 1.8 ft visibility. Phosphorus: 255 µg/L. Chlorophyll-a (algae): 72.6 µg/L. Surface area: 1410 acres.
Is Lou Yaeger Lake safe to swim in?
- The F is nutrients and algae, not a swimming clearance. Lou Yaeger Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, nutrients (phosphorus, nitrogen), turbidity. Check local advisories before you swim.
What is the water temperature of Lou Yaeger Lake?
- Lou Yaeger Lake typically sits around 70°F at the surface in September, from 87 EPA Water Quality Portal field readings (2012–2022). That is a typical value for the month, not a live reading.
Are there boat ramps on Lou Yaeger Lake?
- Lou Yaeger Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Lou Yaeger Lake. Public access is listed as yes.
Explore Lou Yaeger Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
Species activity outlook by water temperature and season
Where to stay at Illinois's top lakes, each with its grade
Very high nutrients, dense algae, poor clarity
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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)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Named boat-access points from the USGS National Boat Ramps inventory