SAN FRANCISCO-In accordance with the National Environmental Policy Act (NEPA), Golden Gate National Recreation Area is beginning an environmental assessment (EA) to evaluate the potential impacts from the removal of an earthen dam at Tennessee Valley. The proposed project would improve visitor safety and access to Tennessee Beach by reducing the potential for flooding during the rainy season.
The dam was constructed around 1960 and is situated on top of marsh soil. It was not engineered to today’s standards and the 2-acre pond it impounds was used solely for duck hunting before the area became National Park Service property.
If the dam suddenly broke when the water level in the pond is high, the depth and velocity of water flowing downward toward the beach could be hazardous. The Tennessee Valley Trail runs alongside the pond and its lower section, which provides access to the beach, is closed during winter storm flows, with a safety warning for visitors posted at the trailhead.
In addition to the removal of the dam, the proposed project will consider restoration of the ecological habitat of the lower valley. The pond is home to the threatened California red-legged frog, but sediment buildup and encroaching vegetation have degraded its value as a natural resource. The EA explores potential actions that would create new breeding ponds for the species at other locations in the watershed.
Closures for the dam’s removal would be temporary and coordinated to reduce impacts to visitor access, which will improve overall since the removal eliminates the need for a seasonal trail closure.
The EA process for this project begins today, Aug. 1, 2022 and is expected to be completed in spring 2023. The 30-day public comment period, in accordance with the NEPA, will begin approximately October 2022. Comments for the EA will be accepted through the NPS Planning, Environment & Public Comment portal. Public notification with details on how to provide comments will be released shortly before the public comment period.
We appreciate the public’s support and participation in this process to improve visitor safety and access in the popular Tennessee Valley area of Golden Gate National Recreation Area.
Source: U.S. Department of the Interior, National Park Service
