IED event in Alabama, Big Creek Lake area, United States of America on Mon 25th May 2026

A routine maintenance dive at an Alabama reservoir turned into a major multi-agency emergency response after divers discovered a grenade-type improvised explosive device attached to the dam. The J.B. Converse Reservoir, a 3,600-acre body of water also known as Big Creek Lake, serves as the sole drinking water source for roughly 350,000 people in and around Mobile, Alabama.

The device was found by divers who were conducting a standard survey of the Converse Reservoir Dam for routine repairs and maintenance. Once the IED was located, contractors immediately alerted the Mobile County Sheriff’s Office, which then coordinated a sweeping multi-agency response. The Gulf Coast Regional Maritime Response and Render-Safe Team led the retrieval effort, working alongside the FBI Bomb Squad, the Mobile Police Department Explosive Ordnance Detail, the Alabama Law Enforcement Agency Bomb Squad, and the Daphne Search and Rescue Team. Together, the teams analyzed the device, brought it to the surface, and safely detonated it.

Built in 1952, the Converse Reservoir holds more than 17 billion gallons of water and sits within a 9,000-acre buffer zone managed by the Mobile Area Water and Sewer System. Seven waterways feed into the lake, including Big Creek, Crooked Creek, Hamilton Creek, Juniper Creek, Collins Creek, Long Branch, and Boggy Branch, draining a surrounding watershed of roughly 104 square miles. The dam is classified as a high hazard potential structure, meaning a structural failure would likely result in loss of human life. Both the reservoir and dam carry a federal designation as critical infrastructure.

MAWSS Director Bud McCrory called the discovery “an unprecedented threat,” noting that the agency was fortunate the device was found before it could damage the water supply or injure anyone. Investigators are now working to determine how the IED ended up in the reservoir and how long it had been there, while the agency moves forward with plans to increase security around the dam.

The reservoir has had an eventful recent history for anglers and boaters. MAWSS closed the lake to recreational boating and fishing in February 2025 over concerns about invasive species and long-term water quality protection. Community members pushed back with a lawsuit, and Big Creek Lake reopened to fishing in April 2026 as part of the lawsuit settlement, though boat rental options remain limited to help protect the water supply.