Glendale Lake
Pope County, Illinois84 acresView mapDirections
Nutrients and algae run well above the regional average.
↓ down from B at the last regrade
- Hypereutrophic
- Impaired · Turbidity
- #2 of 2 in the county
- 37 ft max depth
- Limited data
Glendale Lake in Pope County, Illinois has a water quality grade of F (Algae-prone). Water clarity: 4.8 ft visibility. Phosphorus: 23 µg/L. Chlorophyll-a (algae): 38 µg/L. Surface area: 84 acres.
- Clarity
- 4.8 ft
- Typical in September
- 75°F
- Max depth
- ~37 ft est.
- Area
- 84 acres
- Type
- Hypereutrophic
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Stays near Glendale Lake
Compare lakeside cabins, hotels, and vacation rentals near Glendale Lake in Pope 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 Glendale Lake are listed below.
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Watch Glendale Lake’s letter
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Glendale Lake is a 84-acre highly nutrient-loaded hypereutrophic lake in Pope County, Illinois with an estimated average depth of about 37 feet. Water quality is graded F based on 2 sampling years through 2020. Compared to the 1 other monitored lakes in Pope County, Glendale Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Illinois EPA, last sampled 2020-11-02. Grade methodology: LakeQuality methodology.
What Glendale Lake is good for
From access and monitoring records, not editorial picks.
- Camping2 public campgrounds nearby
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. Glendale Lake is listed impaired under Clean Water Act §303(d) (IR 5) for turbidity. Check local advisories before you swim.
Water Quality Grade: F (Algae-prone)
Murky, only visible to about 4.8 ft. Phosphorus 23 µg/L. Chlorophyll-a 38 µg/L. TSI 57. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4.8 ft | Not graded |
| Phosphorus | 23 µg/L | Fair |
| Chlorophyll-a (Algae) | 38 µg/L | Poor |
| Trophic State Index (TSI) | 57 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Water Temperature
Glendale Lake typically sits around 75°F at the surface in September. Summer average is about 75°F. Usually warmest in Aug (about 77°F) and coldest in Nov (about 54°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 332 field readings (2010–2020) via the EPA Water Quality Portal. See the full Glendale Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~37 ft est. |
| Average Depth | ~14 ft est. |
| Surface Area | 84 acres |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Illinois has not published bathymetry for Glendale 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.
Recreation & Access
Public campgrounds near Glendale Lake
- Oak Point - Lake Glendale0.4 km
- Duck Bay - Lake Glendale0.5 km
Nearest public campgrounds in the USGS National Map inventory, within about 3 miles. An empty list means USGS records no campground that close, which is not the same as camping being unavailable. Where the source gives an official reservation link, it is used; the cabin and hotel search does not cover campsites. More camping lakes
Fishing Glendale Lake
Reservoir Info (USACE NID)
Glendale Lake is a man-made reservoir impounded by the Lake Glendale (completed 1938), built primarily for recreation on the TR-SUGAR; earth-type dam, 38 ft tall and 975 ft long.
- Surface area
- 84 ac
- Normal storage
- 860 ac-ft
- Max storage
- 1,814 ac-ft
- Drainage area
- 2 sq mi
- Hazard class
- Significant
- Owner
- USDA FS
Source: USACE National Inventory of Dams, NID ID IL00102 · Operator website
EPA Impairment Status
Glendale Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit IL_RAZO · Official waterbody report · Matched by proximity (2.93 km)
County Ranking
Ranked #2 of 2 lakes in Pope County
Nearby Lakes in Pope County
Frequently asked questions about Glendale Lake
Where is Glendale Lake?
- Glendale Lake is a lake in Pope County, Illinois. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Glendale Lake?
- Glendale Lake in Pope County, Illinois has a water quality grade of F (Algae-prone). Water clarity: 4.8 ft visibility. Phosphorus: 23 µg/L. Chlorophyll-a (algae): 38 µg/L. Surface area: 84 acres.
Is Glendale Lake safe to swim in?
- The F is nutrients and algae, not a swimming clearance. Glendale Lake is listed impaired under Clean Water Act §303(d) (IR 5) for turbidity. Check local advisories before you swim.
What is the water temperature of Glendale Lake?
- Glendale Lake typically sits around 75°F at the surface in September, from 332 EPA Water Quality Portal field readings (2010–2020). That is a typical value for the month, not a live reading.
How deep is Glendale Lake?
- No published bathymetric survey covers Glendale Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 37 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate. The lake covers 84 acres.
Are there campgrounds on Glendale Lake?
- Glendale Lake has 2 public campgrounds from USGS The National Map within 5 km, including Oak Point - Lake Glendale, Duck Bay - Lake Glendale. This is a location join, not a booking. Cabins and hotels are listed separately; campsite reservations use the official link when the source provides one.
Explore Glendale Lake across LakeQuality
10.5 mi away · 100 ft
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
52 measurements from 3 monitoring stations, 2020. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- illinois epa
IL_EPA_WQX52 samples · 2020
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Public campgrounds from USGS The National Map Structures, within about 3 miles