Where is Heidecke Lake?

Heidecke Lake is a lake in Grundy County, Illinois. Its water-quality measurements are published by Illinois EPA and shown on this page as reported.

How deep is Heidecke Lake?

Heidecke Lake has a maximum depth of 59.1 feet and an average depth of 9.8 feet. The lake covers 1913 acres.

Are there boat ramps on Heidecke Lake?

Heidecke Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Heidecke Lake. Public access is listed as yes.

Can I fish at Heidecke Lake?

Heidecke 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.

Heidecke Lake

Grundy County, Illinois1,913 acresView map Directions

No nutrient or algae sampling on record from Illinois EPA for this lake.

Max depth

59.1 ft

Bathymetric survey

Area

1,913 acres

Surface area

Shoreline

23.7 mi

Measured length

Impaired · Mercury
59 ft max depth
Public access

See the measurements Directions Where to stay

Heidecke Lake in Grundy County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Maximum depth: 59.1 ft. Surface area: 1913 acres.

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Heidecke Lake is a 1,913-acre lake in Grundy County, Illinois with a maximum depth of 59 feet (10-foot average). Limited fish-species data available. Public access is available with 1 public boat landing.

Source: EPA Water Quality Portal sampling records, Illinois EPA. Methodology: how these readings are compared.

What Heidecke Lake is good for

From access and monitoring records, not editorial picks.

Boat launch1 documented ramp
Deep water59.1 ft surveyed max depth
Big water1,913 acres

Swimming conditions

No reading

Not rated

Nutrient and algae readings are not a swimming clearance. Heidecke Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, pesticides, pCBs. Check local advisories before you swim.

Whether Heidecke 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.

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Water quality measurements for Heidecke Lake

These are the measurements Illinois EPA publishes for Heidecke 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. TSI undefined.

Ask about Heidecke Lake

Answers come straight from the public measurements and survey records on this page.

Lake Details

Max depth

59.1 ft

Average depth

9.8 ft

Surface area

1,913 acres

Shoreline

23.7 mi

Public access

Yes

Listed by Illinois EPA

Recreation & Access

Boat Landings

Yes

Public Access

Heidecke LakePublic

Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps

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Stays near Heidecke Lake

Compare lakeside cabins, hotels, and vacation rentals near Heidecke Lake in Grundy 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.

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Fishing Heidecke Lake

→ Heidecke Lake fishing regulations (limits, seasons, special rules)

EPA Impairment Status

Heidecke Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

MercuryPesticidesPCBs

Designated uses not supporting: Fish consumption.

Source: EPA ATTAINS assessment unit IL_SDX · Official waterbody report

Nearby Lakes in Grundy County

Negro Slough1.3 miView →Goose Lake2.6 miView →Dresden Cooling Lake3.7 miView →Milliken Lake8 miView →Hawk Lake9.3 miView →Braidwood Power Plant Cooling Pond11.3 miView →

Frequently asked questions about Heidecke Lake

Where is Heidecke Lake?: Heidecke Lake is a lake in Grundy County, Illinois. Its water-quality measurements are published by Illinois EPA and shown on this page as reported.
What is the water quality of Heidecke Lake?: Heidecke Lake in Grundy County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Maximum depth: 59.1 ft. Surface area: 1913 acres.
Is Heidecke Lake safe to swim in?: Nutrient and algae readings are not a swimming clearance. Heidecke Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, pesticides, pCBs. Check local advisories before you swim.
How deep is Heidecke Lake?: Heidecke Lake has a maximum depth of 59.1 feet and an average depth of 9.8 feet. The lake covers 1913 acres.
Are there boat ramps on Heidecke Lake?: Heidecke Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Heidecke Lake. Public access is listed as yes.
Can I fish at Heidecke Lake?: Heidecke 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.