Johnson Dam Breach Plan
Originally Published: August 28, 2024
County Eyes “Blow & Go” Approach
Jim Gotsch, Director of the Department of Public Works & Transportation (DPWT), obtained approval from the county commissioners last week for an emergency procurement of services to breach the Johnson Pond dam. An additional $175K was needed to support hiring a contractor for the work because the current capital improvement project (CIP) only included $331K.
Back in 2020, the county received a violation from the Maryland Department of the Environment (MDE) stating the dam was failing and needed attention. According to Gotsch, a county employee has driven to the dam every weekend for the past few years to take photos and ensure it’s holding. In May 2020, the commissioners at the time approved funding for design work to repair the dam, but then decided in 2022 the plan was too expensive. DPWT was “instructed to investigate breaching the dam as an alternative,” according to Gotsch.
The property known as St. Mary’s Crossing, where the dam is located, was once the Claude Johnson Farm along St. Andrew’s Church Road. The area is planned for a long-awaited sports complex, in partnership with the Maryland Stadium Authority. A more than 60 acre pond, created by the 100+ year old dam, will drain downstream when the embankment is demolished.
Several strategies were considered. At $1.97M, the Regenerative Stream Conveyance Approach was the most costly option. Blow & Go plus removal of sediment was an estimated $1.5M. Blow & Go without sediment removal, the proposed option, describes “careful removal of the dam and replacement of stone beneath it,” Gotsch said. Two bids were received for the option chosen, with an $800K bid from a “local contractor,” according to Gotsch. The winning bid was only $459K. Time is of the essence after the county received an MDE letter in March 2024 stating “the embankment is in an accelerated state of disrepair and is in imminent danger of collapse.”
Director Gotsch said the pond collects water draining from as far north as the airport. Drainage continues through the pond/dam into the St. Mary’s River, which flows through St. Mary’s River State Park south through Great Mills. Eliminating the dam removes potential danger, and the county is not responsible for removing sediment unless they don’t address the dam and it blows. “Sediment flows down stream all the time,” in other instances Gotsch said.
