by Sandy Guldman
The southeastern corner of Creekside Marsh at Hal Brown Park in Kentfield had deficient tidal ex-change because the single culvert connecting it to Corte Madera Creek was too small. When the potential for funding from the Regional Water Quality Control Board’s Supplemental Environmental Program came up, Friends proposed replacing the culvert with a much larger one; the proposal was accepted and we signed contracts with Ross Valley Sanitary District, who provided the cash, and the Regional Board. At that point, we hired engineers to design the project.
It was a complicated project because the Kentfield Force Main—two high-pressure sewers—are under the multi-use path along the creek and above the culvert. The initial design of a single box culvert was too expensive and presented some logistical challenges, so the project was delayed and redesigned to incorporate three parallel plastic pipes with the same capacity as the single box culvert.
Thanks to significant logistical and financial support from Marin County Parks, the culvert was successfully installed this fall, just meeting the October 31 construction deadline. Kudos to Chris Bramham and Craig Richardson! We look forward to increased flow and better habitat in the marsh now that water can freely move in and out.