URA consultants warn Stevens Lake dam at Forest Park is failing; propose sediment testing and two repair options

Consultants briefing the Fort Gillem Urban Redevelopment Authority on Stevens Lake said the lake’s dam is in “really, really poor condition” and recommended targeted sediment testing and a conditional assessment before deciding whether to renovate the dam or breach it.

Jim Harden, a dam and surface‑water specialist with Walden Ashworth, told the authority that the dam’s riser structure is not functioning and that “there’s only 1 foot above the normal pool to the top of dam,” creating little freeboard and active erosion on the downstream slope. Harden said he saw concrete pipe sections displaced and trees growing on slopes that mask seepage and make inspection difficult. “The dam is already starting to fail,” he said.

The authority’s environmental consultant with OASIS said staff lack data on what contaminants, if any, are in the lake sediment and recommended sampling before any large‑scale action. “I don’t know,” the OASIS consultant said of contaminant levels. “I’m gonna say I don’t know,” and proposed collecting five to six sediment samples by boat for laboratory testing to check for lead, PCBs, VOCs or other compounds that would affect disposal and remediation strategy.

Why it matters: Stevens Lake drains a portion of the former Fort Gillem property and serves stormwater detention for nearby parcels. Consultants said the dam’s current limited storage and reduced height mean the structure provides little detention benefit and is at risk if a major storm were to occur. Sediment released by a breach could travel downstream, and previous site work uncovered lead‑impacted soils on adjacent parcels.

Options and costs: Harden described two options: renovate and retain the dam—replacing the riser, building an engineered forebay to capture sediment, repairing downstream erosion and potentially adding walking trails and parking—or breach the dam (as was done at Marchman Lake) and regrade the reach as open channel. Harden said a renovation that converts the site into a usable amenity would likely cost more than breaching but could produce a park‑like asset. He said a condition assessment with borings, survey and hydraulic/hydrologic analysis is required to provide engineer‑level cost estimates.

Sampling and next steps: The OASIS consultant proposed adding low‑cost sediment sampling to the consulting scope so the authority would know whether sediments require disposal to a landfill, can be reclaimed on site, or can be left in place with remedial controls. The consultant said he has asked the Army for historical data on sediments and is coordinating with the authority’s geologist, Ashley Butterfield, who confirmed the authority can obtain samples and testing.

Contract proposal and Brownfield work: The OASIS representative presented a proposed annual consulting scope and budget of about $65,000 that would include (a) a conditional assessment/visual inspection funding allowance, (b) boat‑based sediment sampling and testing, and (c) preparation of a Brownfield Covenant/CSR for the old Forest Park fire station parcel to bring that parcel into the Georgia Brownfield program. The consultant said the fire‑station parcel remains the only piece of the Fort Gillem property not enrolled in the Brownfield program and recommended enrolling it to reduce liability and improve marketability.

Insurance and Army responsibility: Consultants reminded the authority that environmental insurance typically excludes lead and that the Army retains some environmental obligations under deed covenants tied to the BRAC transfer. The OASIS consultant said the authority will ask the Army for any historical environmental sampling they hold but cautioned that insurance and regulatory coverage vary by contaminant and circumstance.

Board response and timeline: Board members asked technical questions about access, erosion, storage capacity and how much surveying and borings would be needed. The authority did not take a vote on a contract that evening; the OASIS consultant left copies of the proposed scope and budget and said staff would bring a resolution on the contract to the next meeting. Board members agreed to schedule a site visit and to review the consultant scope and the Army’s historical data before authorizing major work.

What remains unresolved: The presence and concentration of contaminants in the sediment are unknown pending sampling results; the authority has not committed to either breaching or renovating the dam; and no contract resolution was adopted that night. The consultant recommended sampling now to better inform the engineering assessment and potential remediation costs.

Ending: The authority’s staff said they will arrange the recommended site visit and review the OASIS scope; the consultant expected a contract resolution to be ready at the next authority meeting.