Heidecke Lake in Grundy County reopened to boaters on Friday.

The Illinois Department of Natural Resources delayed the traditional April 1 opening of the lake because of unusually low water levels caused by drought conditions this spring

Located near Morris, Heidecke Lake is a former cooling lake for a power generation plant. IDNR leases the site to provide public outdoor recreational opportunities.

For the first time since the utility site was decommissioned in 2007, water levels at Heidecke Lake dropped too low to allow safe navigation by boats and other watercraft, as well as by first responders who could be called upon to conduct rescues on the lake, the IDNR said in a news release.

Ideal water levels for the lake are about 510 feet, with safe navigation for watercraft typically possible at 508 feet or higher. The lake reached 508 feet as of Thursday, the IDNR said.

Boaters must still exercise caution while launching and navigating because shallow areas persist throughout the lake, IDNR said. Boaters also should abide by all normal lake rules.

“Heidecke Lake is a popular spot for anglers, and IDNR appreciates their patience as department staff carefully monitored water levels to ensure safety for all who enjoy recreating on this lake,” said IDNR Director Natalie Phelps Finnie. “We look forward to welcoming boaters back just in time for Illinois Free Fishing Days June 19 to 22.”

IDNR staff will continue to monitor water levels in the lake. Questions can be directed to the Heidecke Lake site office at 815-942-6352.