Two attorneys with ties to an environmental group have rekindled the long-simmering controversy over removal of a Florida dam built for a shipping canal that Congress deauthorized in 1990.

Bruce Kaster and Joseph Little on Dec. 5 petitioned the U.S. Forest Service to implement binding obligations—to which the service agreed more than two decades ago—to take down the George Kirkpatrick Dam. The 7,200-ft-long, 22-ft-high earthen structure impounds the Rodman Reservoir in Marion and Putnam counties in north-central Florida.

The dam was built in 1968 on the Ocklawaha River, the principal tributary of the St. Johns River, for the 107-mile Cross-Florida Barge Canal, on which construction was stopped in the 1970s. Its impoundment infringes on the Ocala National Forest, and U.S. Forest Service regulations required its removal when its 2002 permit expired.

According to the Florida Times-Union, Kaster and Little are members of Florida Defenders of the Environment, which has opposed the dam for decades. The group says the removal would allow reservoir water to return to the Ocklawaha River.

The last of a series of special-use permits for the dam expired in 2002, but it has continued to operate because the 9,600-acre reservoir is a major recreational draw that provides economic benefits for one of Florida’s poorest counties.

But its existence has annoyed relations between Putnam County and Jacksonville, at the mouth of the St. Johns, since construction of the Cross-Florida Barge Canal halted.

Plans to dredge the St. Johns, which would help Jacksonville to compete with other ports, now have revived the controversy.

St. Johns Riverkeeper, another environmental group, threatened to sue the U.S. Army Corps of Engineers to prevent the proposed dredging to reduce the threat of salinity in the St. Johns. If the Kirkpatrick dam is breached, the added flow from the Ocklawaha would help to achieve that goal, says Lisa Rinaman, a Riverkeeper spokeswoman.

Petitioner Little says he is hopeful for progress now because some of the people most opposed to removing the dam are no longer in the community. But remaining reservoir supporters have continued to express bitter criticism of the proposal in public meetings.

Media reports say the dam removal would cost between $20 million and $25 million.