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This lake is closed to fishing as of October 9, 2018 due to waterfowl season.

Lake Information

County: Grundy

Acreage: 1955

Average Depth: 9.02 feet

Shoreline Length: 17 miles

Recreational Amenities

Boat Fishing? Unrestricted

Boat Ramps? Yes

Boat Rental? No

Skiing? No

Swimming? No

Picnicking? Yes

Camping? No

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There are zebra mussels in this lake.

Lake Status Summary  ( Full PDF Report )

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Fish Status



Since 2008, there has been little evidence of reproduction and/or recruitment for channel catfish. The average size for channel catfish collected in IDNR surveys has steadily increased, and in 2016, the average size catfish collected reached an all-time high, surpassing the long-term average by nearly 3 inches.



Crappie were poorly represented in the 2016 fall survey, as total number collected dropped by more than 50%. Despite being stocked, black crappie have been outnumbered by white crappie in each of the past several surveys. Angler reports indicate very good crappie fishing in 2016, both in terms of numbers and size. Black crappie are stocked on an as-available basis. Site Regulation: 15 fish daily creel.



The hybrid striped bass collection increased dramatically in 2016, accounting for 12.4% of the total number of fish collected (excluding shad) and 18.9% of the total poundage of fish collected. Electrofishing catch rates reached an all-time high. The majority of the fish collected exceeded 17” and more than 10% were 25” or larger. Site Regulation: 10 fish daily creel with only 3 fish 17” or longer.



The 2016 survey rates as the fewest largemouth bass ever collected in a major IDNR fall survey. Length frequency distribution is very sporadic with some consistency up to approximately 10 inches after which point numbers decline. Young-of-the-year bass were non-existent in this survey which points to poor or failed spawning success and/or poor survival of young bass. The absence of rooted aquatic macrophytes likely plays a role in this situation. The largemouth bass population at Heidecke has been poor for the last 10+ years. Angler catch rates are substandard. Site Regulation: 12” to 18” protected slot, 2 fish under 12”, 1 fish over 18”.



Spring 2016 trap netting catch rates declined slightly, with males accounting for 57% of the collection. The largest fish captured measured 48” and weighed 30 pounds while the average muskie collected measured 37.8”. Big fish (those 45” and larger) are becoming increasingly more prevalent in these spring surveys. Site Regulation: 48” minimum length limit.



In the 2016 fall survey, 35% of the smallmouth collection fell within the protected slot (12” to 18”). The percentage of larger smallmouth bass is trending upwards. The number of fish that were 15” and larger more than doubled from the previous survey, while the density of 18”+ fish increased as well. The overall average length for smallmouth bass collected in 2016 was 13.0”. Site Regulation: 12” to 18” protected slot, 2 fish under 12”, 1 fish over 18”.



Following the record-setting years of 2012 and 2014, the walleye collection declined somewhat in 2016, although catch rates were not far from the long-term averages. Length frequency was fairly consistent which indicates good survival and recruitment of stocked fish. Walleye stockings have been conducted annually, except for 2010, with stockings generally averaging 35 fish/acre. Smaller walleye were not well represented in this survey and 83% were legal size. The average size walleye collected was 19.5” while nearly 8% of the 2016 collection was 25” and larger. Site Regulation: 16” minimum length limit, 3 fish daily creel.



White bass numbers increased in the 2016 survey due to the prevalence of younger fish. White bass averaged 10.3”, which is nearly 2” less than the long term average.



The 2012 year class continues to represent a major portion of the yellow bass population, and this age group accounted for roughly 60% of the 2016 fall survey collection. Yellow bass 9” and larger compromised nearly 42% of the adult fish collected. This should result in continued good angling opportunities. Note: Yellow bass are not included in the aggregate “striper” limit.

Location: Heidecke Lake State Fish and Wildlife Area is located in Grundy County approximately 1 mile south and 8 miles east of Morris, between Illinois Route 47 and Interstate Route 55 on Lorenzo/Pine Bluff Road.

Description: Formerly a cooling reservoir, Heidecke Lake has 1,955 surface acres of water with 75% of shoreline comprised of rock rip-rapped dikes. A "safe harbor" created by breakwaters was constructed in 1993. There are no horsepower limitations; maximum speed is 40 mph except in designated "no wake" areas; working gasoline engine required as main propulsion unit; boats under 14' are not recommended. Zebra mussels have been found in Heidecke Lake and boaters should take appropriate measures upon departure. Shore angler access is located on the east side of lake off Dresden Road with portions of the center and east dike open to bank fishing. A handicapped fishing pier is located on the east side of the lake as well.

History and Status of the Sport Fishery: The fishery is evaluated via biennial major surveys and annual species-specific surveys. Attempts to introduce aquatic vegetation have generally failed. Bass spawning habitat has been installed at various locations and other habitat enhancement projects are planned. Heidecke Lake receives annual stockings of walleye and hybrid striped bass. Pure muskellunge are stocked every third year, while black crappie and largemouth bass are released based upon availability. A special mercury advisory is in effect for smallmouth bass 18" and larger which limits consumption to one meal per week for the most sensitive populations.

Heidecke Lake is maintained by periodically pumping water from the Illinois River. As a result, the lake supports a variety of fish species in addition to those listed above, including common carp, quillback, freshwater drum and others. Heidecke Lake is supported by a thriving gizzard shad forage base as well as various other minnow species. Round gobies have been recently discovered as well.

Additional Lake Information: Swimming, wading, water skiing and sail boating are prohibited. Heidecke Lake is open daily from 6:00 a.m. to sunset from April 1 to ten days prior to the opening of the waterfowl season. There are no horsepower limitations; maximum speed is 40 mph except in designated "no wake" areas; working gasoline engine required as main propulsion unit; boats under 14' are not recommended. A recently refurbished three-lane concrete boat ramp with fully blacktopped 100+ car/trailer parking is available. Boat launch is handicapped accessible. The boat access is open daily from 6:00 a.m. to sunset; bank fishing access on the center and eastern dikes opens at 6:30 a.m. and closes at sunset. Since windy conditions can produce treacherous waves, the lake can be closed at the discretion of the site superintendent.

Additional Site Specific fishing regulations:
Boaters are required to have operational gasoline motors. No horsepower limitations.
All fish species - Two pole and line fishing only.
Largemouth or Smallmouth Bass – 12” to 18” protected slot, 2 fish under 12”, 1 fish over 18”
Hybrid Striped Bass – 10 fish daily creel/3 fish 17” or longer
Crappie – 15 fish daily creel
Muskellunge – 48” minimum length limit
Walleye – 16” minimum length limit, 3 fish daily creel

Contact Information:
Heidecke State Fish and Wildlife Area
IDNR Fisheries Biologist, Rob Miller

There were 5 tournaments held on this waterbody in 2018.

Species Total Fish Caught
Crappie 6
Largemouth Bass 41
Smallmouth Bass 47
Walleye 29
White Bass 2

Top 5 Largemouth Bass caught on this waterbody in 2018 tournaments:

1     2.12 lbs
2     2.00 lbs
3     1.38 lbs
4     0.00 lbs
5     0.00 lbs

Top 5 Bag Weights of Largemouth Bass caught on this waterbody in 2018 tournaments:

1 25.13 lbs
2 16.25 lbs
3 0.00 lbs
4 0.00 lbs
5 0.00 lbs

Multiple day tournaments are listed with *end date and

Interested in participating in one of these public tournaments? Contact us with tournament ID for more information.

2019-2020 Approved or Pending Tournaments
Start Date ID Approval Ramp Location Bank/Boat
Max Boats Species Youth? Open to Public?
April-1814519PendingHeidecke Lake Boat Ramp boat
25Largemouth Bass
Smallmouth Bass
April-1914782PendingHeidecke Lake Boat Ramp boat
10Multiple SpeciesNo
May-2314569PendingHeidecke Lake Boat Ramp boat
30Largemouth Bass
Smallmouth Bass
August-2313811PendingHeidecke Lake Boat Ramp boat
30Largemouth Bass
Smallmouth Bass
October-0413830PendingHeidecke Lake Boat Ramp boat
30Largemouth Bass
Smallmouth Bass