Plan to remove dam in Marin County's Tennessee Valley could be hampered by endangered frog
MARIN COUNTY -- A plan in place to remove a dam for safety reasons near a North Bay beach has raised questions about the impact the removal could have on an endangered frog.
The National Parks Service is proposing to remove a small earthen dam in the Tennessee Valley coastal watershed to eliminate a safety hazard to visitors at the beach downstream of the dam.
But there are questions about what will happen to a threatened species that relies on the existing pond.
Marin Conservation League Ecologist Terri Thomas searches for a small native amphibian that has made this pond its home, on one side of the dam.
On the other end, water gets released from the earthen dam built in the 1960s by a private landowner for hunting and waterfowl. The stream snakes its way to the ocean.
But the National Parks Service says there are safety issues with flooding and even the possibility of a breach.
The plan is to reshape the landscape and water flow by removing the dam, ultimately restoring the Tennessee Valley to its natural state.
"The pond will shrink because the water will go out from the dam. There will be more of a connection with the water below the dam and this water above," said Thomas.
Taking down the dam will impact the federally threatened California red-legged frog, made famous in a short story by Mark Twain. The frog has made a comeback.
"The red-legged frogs are back at the cove and with that, a big effort to make sure they're sustainable in the valley," said Thomas.
Visitors have to walk upstream to understand how the National Park Service will minimize impact on the native frogs.
Egg masses will be scooped and transferred to smaller ponds to be built nearby as part of the project. However, there is pushback to the plan.
Groups like the Marin Watershed Alliance are raising questions about herbicide used to remove invasive plants as part of the project. So is former Fairfax mayor Larry Egger.
"Pesticides move when it rains it will carry them off to the sea and there's no need to use poison on public lands," said Egger who represents the North Coast Rivers Alliance.
But Thomas and the Marin Conservation League believe removing the dam will be a win for the frogs, and the right path in continuing to restore the valley as the frog's natural habitat.
"It's so gorgeous now. It's flourishing. Every time I walk, I see ground nesting birds that wouldn't have covered ground nests. It's been exciting and aquatic species are part of that," said Thomas.
Her focus is a decades-long push by conservationists, to transform a place of natural beauty, to its older self.
The project recently got through a major hurdle. The California Coastal Commission voted unanimously to endorse the park service's proposal.
The NPS says the goal is to increase visitor safety and access to the lower section of the Tennessee Valley Trail. The area is closed during the winter when the water level in the pond is highest and at risk of flooding.
There's no finalized ttimeline on when the dam removal will begin.