Heidecke Lake
Info / Grundy County
Family Friendly
No
Handicap Access
Yes
Boat Fishing
Yes - Unrestricted
Boat Ramps
Yes
Boat Rentals
No
Camping
No
Picnicking
Yes - More Info
Skiing
No
Swimming
No
Trout Stocking
No
Zebra Mussels
Location 1955 acres
Fishing Outlook
Channel Catfish
Poor
Channel Catfish have not been collected in any large numbers for quite a few years, possibly due to recruitment issues.
Smallmouth Bass
Very Good
The fall 2024 survey resulted in a total of 204 Smallmouth Bass collected ranging from 80 mm (3.1 inches) to 475 mm (18.7 inches), with 188 of those fish greater than Stock size (7.0 inches). Average length was 345 mm (13.6 inches). The Smallmouth Bass catch rate remained similar to the 2022 survey. Size distribution increased while body condition remained fair for the larger size groups.
Striped Bass x White Bass (Wiper)
Good
The fall 2024 survey resulted in a total of 128 Hybrid Striped Bass collected ranging from 84 mm (3.3 inches) to 636 mm (25 inches), with 116 of those fish greater than Stock size (8.0 inches). Average length was 473 mm (18.6 inches). The Hybrid Striped Bass catch rate was similar to the 2022 survey, as was the size distribution. Body condition was poor for all the larger individuals.
White Bass
Good
White Bass were essentially absent from the fall 2024 survey though this is not indicative of the population.
Crappie spp.
Good
The spring 2024 trap netting survey resulted in a total of 218 Black Crappie collected ranging from 81 mm (3.2 inches) to 346 mm (13.6 inches), with 217 of those fish greater than stock size (5.0 inches). Average length was 276 mm (10.9 inches).
Walleye
Very Good
The spring 2024 trap netting survey resulted in a total of 85 Walleye collected ranging from 383 mm (15.1 inches) to 693 mm (27.3 inches), with 85 of those fish greater than Stock size (10.0 inches). Average length was 549 mm (21.6 inches). The vast majority of Walleye collected were legal size (over 16 inches).
Muskellunge
Very Good
The spring 2024 trap netting survey resulted in a total of 149 fish collected ranging from 30 to 49.2 inches (two fish over 48 inches were collected). Average length was 34 inches for males and 39 inches for females. A state-record fish was collected in the 2023 spring trap netting survey (39.8 pounds).
Yellow Bass
Good
The fall 2024 survey resulted in a total of 17 Yellow Bass collected ranging from 90 mm (3.5 inches) to 266 mm (10.5 inches), with 15 of those fish greater than Stock size (4.0 inches). Average length was 213 mm (8.4 inches). Yellow Bass, while not necessarily a targeted sportfish, likely end up in the angling creel from time to time.
Bluegill
Good
The Fall 2024 survey resulted in a total of 547 Bluegill collected ranging from 30 mm (1.2 inches) to 223 mm (8.8 inches), with 226 of those fish greater than stock size of 3.0 inches. Average length was 95 mm (3.7 inches). The Bluegill catch rate slightly declined from the 2022 survey, though size distribution of the population greatly increased with a very high PSD-P value. Large Bluegill were not evenly distributed across sites and were collected in large numbers at a few locations. Bluegill body condition was quite good which suggests good growth potential.
Largemouth Bass
Poor
The fall 2024 survey resulted in a total of 68 Largemouth Bass collected ranging from 58 mm (2.3 inches) to 465 mm (18.3 inches), with 25 of those fish greater than Stock size (8.0 inches). Average length was 216 mm (8.5 inches). Largemouth Bass catch rate declined from the 2022 survey though the number of Stock-sized fish increased as did the size distribution of the population. Body condition was excellent for all size groups.
| 2025 | Muskellunge | Adult | 1959 |
| 2025 | Striped Bass x White Bass (Wiper) | Fingerling (1 - 3") | 21232 |
| 2025 | Walleye | Fingerling (1 - 3") | 102815 |
| 2024 | Blacknose Crappie | Fingerling (1 - 3") | 45021 |
| 2024 | Blue Catfish | Adult | 268 |
Contact
815-942-6352
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. A recently refurbished three-lane concrete boat ramp with fully blacktopped 100+ car/trailer parking is available. Zebra Mussels have been found in Heidecke Lake and boaters should take appropriate measures upon departure. Boat launch is handicapped accessible. 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.
Fishery History
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 stocked based upon availability. Heidecke Lake was 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.Site Regulations
Since windy conditions can produce treacherous waves, the lake is closed when wind speeds are projected be 25 mph or greater per the NOAA weather report for Morris, Illinois. Boaters are required to have operational gasoline motors. No horsepower limitations. Swimming, wading, water skiing and sail boating are prohibited. Heidecke Lake is open to fishing daily from 6:00 a.m. till sunset starting April 1 and is closed to fishing 10 days before the opening of the Northern Zone Duck Season. Boats under 14 feet are not recommended.
Site-Specific Fishing Regulations:
- Recreational Use Restriction: Waterfowl Refuge or Hunting Area (see above)
- All Fish: 2 pole and line fishing only and each pole must not have more than 2 hooks or lures attached while fishing
- All live bait greater than 8 inches must be rigged with a quick set rig
- Channel Catfish: 6 Fish Daily Harvest Limit
- Large or Smallmouth Bass: 15 inch Minimum Length Limit; 3 Fish Daily Harvest Limit
- Muskie: 48 inch Minimum Length Limit; 1 Fish Daily Harvest Limit
- Striped, White, or Hybrid Striped Bass: 10 Fish Daily Harvest Limit with no more than 3 fish greater than or equal to 17 inches
- Walleye, Sauger, or Hybrid Walleye: 16 inch Minimum Length Limit; 3 Fish Daily Harvest Limit
- White, Black, or Hybrid Crappie: 15 Fish Daily Harvest Limit
Additional Information
FALL FISHING CLOSURE: October 8
Planning to eat your catch? Fish Consumption Advisory information can be found here: Fish Consumption Advisory Page
Bath Map
