The state is suing a Center Township residents association for not inspecting or repairing the Hull Plan Lake Dam, which was declared unsafe in 2021.

The Department of Environmental Protection filed the lawsuit Monday in Butler County Common Pleas Court against Hull Plan Residents Association, Inc., for not inspecting or repairing the dam and not filing an emergency action plan for protecting downstream residents in the event of a dam failure.

Measuring 25 feet high and 400 feet long, the dam impounds an unnamed tributary to Connoquenessing Creek to form a 220-acre lake along Lakewood Drive. The downstream area contains four residences, one business and 32 people.

The DEP classifies the dam in Category C because of its size and other risk factors. It is less than 40 feet high and in hazard potential Category 1 as a high hazard dam because its failure would put numerous homes or small businesses at risk and result in excessive economic loss.

On June 2, 1990, the DEP issued the association a permit to operate and maintain the dam. On July 16, 2021, the DEP determined the association failed to operate and maintain the dam in a safe condition and declared the dam unsafe.

The DEP notified the association of its determination.

During an Aug. 28, 2025, review, the DEP found the association had not submitted an emergency action plan or annual inspection reports, failed to post notices in public areas that may be affected by a dam failure and the annual registration fee for the structure hadn’t been paid for fiscal year 2024-25, according to the suit.

A draft emergency action plan submitted April 22 by an association engineer didn’t include a breach analysis for the development of an inundation map, the DEP claims.

A June 5 inspection conducted by the DEP found vegetation was 2 to 4 feet high on an embankment on each side of the road around the guard rails. Woody vegetation — including some measuring more than 6 inches in diameter — was growing in the embankment.

The left sidewall of the spillway was cracked, causing a void to develop behind the wall. The right sidewall was cracked and leaning inward. Spillway culvert walls under the road were cracked.

The ceiling area upstream of the spillway culvert has collapsed and the spillway culvert was 75% blocked due to the collapse and was impeding flow capacity under the road, according to the suit.

As a result, the DEP claims the spillway discharge area could not be inspected due to the heavy vegetation and the intake structure and debris catcher couldn’t be inspected because they were under water.

The DEP said inspectors didn’t find primary closure or control mechanism at the dam. They couldn’t inspect the outlet pipe, upstream and downstream embankments, downstream dam toe, abutments and foundation areas due to the heavy vegetation.

On June 30, the DEP issued and served association president Brad Cavaliero with an administrative order to draw down the lake, complete and submit a dam breach analysis and emergency action plan and remove or repair the dam, according to the suit.

The DEP seeks a court order for the association to apply to the Pennsylvania Fish and Boat Commission for a draw down permit, draw down the lake, inspect the outlet system, submit a report on the results of the inspection along with an engineer’s assessment and recommendations and remove or repair the dam.

If the association wants to repair the dam, the DEP wants the court to order the association to submit a repair plan for approval, a plan to refill the lake and submit proof of financial responsibility in the amount of $550,000.

Cavaliero could not be reached for comment Tuesday.