Saganashkee Slough Lake
Cook County, IllinoisView mapDirections
Illinois EPA publishes the water-quality measurements for Saganashkee Slough Lake. Here is what has been measured.
- Hypereutrophic
- Impaired · Algal growth
- 56 ft max depth
- Public access
- Limited data
Saganashkee Slough Lake in Cook County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Water clarity: 0.8 ft visibility. Phosphorus: 170 µg/L. Chlorophyll-a (algae): 108.5 µg/L.
Saganashkee Slough Lake is a highly nutrient-loaded hypereutrophic lake in Cook County, Illinois with an estimated average depth of about 56 feet. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 15 other monitored lakes in Cook County, Saganashkee Slough Lake ranks #11 for water quality.
Source: EPA Water Quality Portal sampling records, Illinois EPA, last sampled 2020-10-20. Methodology: how these readings are compared.
Saganashkee Slough Lake has one public boat landing. If you are planning to stay, you can search lake houses and cabins around Saganashkee Slough Lake on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
What Saganashkee Slough 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. Saganashkee Slough Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, metals (other than mercury), nutrients (phosphorus, nitrogen), pCBs, sediment / turbidity, turbidity. Check local advisories before you swim.
Whether Saganashkee Slough 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 Saganashkee Slough Lake
These are the measurements Illinois EPA publishes for Saganashkee Slough 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 0.8 ft of visibility. Phosphorus 170 µg/L. Chlorophyll-a 108.5 µg/L. TSI 79.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 0.8ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 170µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 109µg/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. | 79 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Saganashkee Slough Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Saganashkee Slough Lake typically sits around 55°F at the surface in October. Summer average is about 80°F. Usually warmest in Jul (about 83°F) and coldest in Oct (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 (83°F).
Typical surface water temperature by month, from 22 field readings (2010–2022) via the EPA Water Quality Portal. See the full Saganashkee Slough Lake water temperature breakdown →
Lake Details
Max depth
~56 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 Saganashkee Slough Lake.
Lake Size & Watershed
Watershed (drainage) area
7 sq mi
HydroLAKES / HydroSHEDS
Surface area
353 acres
HydroLAKES / HydroSHEDS
Shoreline
3.8 mi
HydroLAKES / HydroSHEDS
Elevation
587 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
- Saganashkee Slough boat launchPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Saganashkee Slough Lake
Compare lakeside cabins, hotels, and vacation rentals near Saganashkee Slough Lake in Cook 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 Saganashkee Slough Lake are listed below.
Top-rated places to stay near Saganashkee Slough Lake
Prices for Oct 23–25, 4 adults. Change dates on the map below.
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Planning a trip? Cabins and lodging at Saganashkee Slough Lake → · more Illinois lake trips
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Fishing Saganashkee Slough Lake
Reservoir Info (USACE NID)
Saganashkee Slough Lake is a man-made reservoir impounded by the Saganashkee Slough 1 Dam (completed 1948), built primarily for recreation on the TRIB CALUMET SAG CHANNEL; earth-type dam, 14 ft tall and 950 ft long.
- Normal storage
- 718 ac-ft
- Max storage
- 2,379 ac-ft
- Hazard class
- Significant
- Owner
- FOREST PRESERVE DISTRICT OF COOK COUNTY
Source: USACE National Inventory of Dams, NID ID IL00870 · Operator website
EPA Impairment Status
Saganashkee Slough 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: Aquatic life, Fish consumption, Other.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit IL_RHH · Official waterbody report
Nearby Lakes in Cook County
Frequently asked questions about Saganashkee Slough Lake
Where is Saganashkee Slough Lake?
- Saganashkee Slough Lake is a lake in Cook County, Illinois. Its water-quality measurements are published by Illinois EPA and shown on this page as reported.
What is the water quality of Saganashkee Slough Lake?
- Saganashkee Slough Lake in Cook County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Water clarity: 0.8 ft visibility. Phosphorus: 170 µg/L. Chlorophyll-a (algae): 108.5 µg/L.
Is Saganashkee Slough Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Saganashkee Slough Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, metals (other than mercury), nutrients (phosphorus, nitrogen), pCBs, sediment / turbidity, turbidity. Check local advisories before you swim.
What is the water temperature of Saganashkee Slough Lake?
- Saganashkee Slough Lake typically sits around 55°F at the surface in October, from 22 EPA Water Quality Portal field readings (2010–2022). That is a typical value for the month, not a live reading.
How deep is Saganashkee Slough Lake?
- No published bathymetric survey covers Saganashkee Slough Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 56 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 Saganashkee Slough Lake?
- Saganashkee Slough Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Saganashkee Slough boat launch. Public access is listed as yes.
Can I fish at Saganashkee Slough Lake?
- Saganashkee Slough 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.
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Where this data comes from
48 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_WQX48 samples · 2020
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Named boat-access points from the USGS National Boat Ramps inventory