Diversey Harbor Lake
Cook County, IllinoisView mapDirections
No nutrient or algae sampling on record from Illinois EPA for this lake.
- Impaired · Mercury
- Public access
- Limited data
Diversey Harbor Lake in Cook County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported.
Diversey Harbor Lake is a lake in Cook County, Illinois. Limited fish-species data available. Public access is available with 2 public boat landings.
Source: EPA Water Quality Portal sampling records, Illinois EPA, last sampled 2023-05-23. Methodology: how these readings are compared.
Diversey Harbor Lake has 2 public boat landings, so a lakefront rental is not the only way to get a boat on the water. If you are planning to stay, you can search lake houses and cabins around Diversey Harbor Lake on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
What Diversey Harbor Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch2 documented ramps
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Diversey Harbor Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury, pCBs. Check local advisories before you swim.
Whether Diversey Harbor 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 Diversey Harbor Lake
These are the measurements Illinois EPA publishes for Diversey Harbor Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data.
Ask about Diversey Harbor Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Diversey Harbor Lake typically sits around 73°F at the surface in September. Summer average is about 67°F. Usually warmest in Sep (about 73°F) and coldest in Nov (about 56°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (56°F) to its warmest (73°F).
Typical surface water temperature by month, from 13 field readings (2013–2023) via the EPA Water Quality Portal. See the full Diversey Harbor Lake water temperature breakdown →
Recreation & Access
- Church Street Power Boat RampPublic
- Burham Harbor - NorthPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Diversey Harbor Lake
Compare lakeside cabins, hotels, and vacation rentals near Diversey Harbor 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.
Top-rated places to stay near Diversey Harbor Lake
Prices for Oct 23–25, 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 Diversey Harbor Lake → · more Illinois lake trips
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Fishing Diversey Harbor Lake
EPA Impairment Status
Diversey Harbor Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Fish consumption.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit IL_QZI · Official waterbody report
Nearby Lakes in Cook County
Frequently asked questions about Diversey Harbor Lake
Where is Diversey Harbor Lake?
- Diversey Harbor 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 Diversey Harbor Lake?
- Diversey Harbor Lake in Cook County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported.
Is Diversey Harbor Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Diversey Harbor Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury, pCBs. Check local advisories before you swim.
What is the water temperature of Diversey Harbor Lake?
- Diversey Harbor Lake typically sits around 73°F at the surface in September, from 13 EPA Water Quality Portal field readings (2013–2023). That is a typical value for the month, not a live reading.
Are there boat ramps on Diversey Harbor Lake?
- Diversey Harbor Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Church Street Power Boat Ramp, Burham Harbor - North. Public access is listed as yes.
Can I fish at Diversey Harbor Lake?
- Diversey Harbor Lake has 2 documented boat landings 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 Diversey Harbor Lake across LakeQuality
Planning a trip around Indiana Dunes?
Diversey Harbor Lake is about 34 miles from Indiana Dunes 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 Indiana Dunes →More lakes in Illinois
Other Lakes in Illinois
Where this data comes from
1 measurement from 1 monitoring station, 2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- USGS Illinois Water Science Center
USGS-IL1 sample · 2023
Analytical methods
- Secchi disk method
Monitoring station identifiers (1)
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
Named boat-access points from the USGS National Boat Ramps inventory