A multi-agency collaboration over the span of 14 months yielded several proposed solutions to the frequent flooding of Pescadero Creek Road, including channel dredging and the construction of a causeway.
The potential solutions were released in an October report and presented by the San Mateo County Resource Conservation District and county representatives at a recent meeting in Pescadero. The concepts were narrowed from a distilled list of 13 solutions through an extensive analysis. Researchers built computer models and tested variables to see what effects they could have on decreasing sediment buildup and mitigating flooding while also benefiting the ecosystem. From there, the most viable solutions fell into three categories, as RCD Executive Director Kellyx Nelson explained: reducing sediment upstream, dredging in the county right of way and perhaps building a causeway that could allow water to flow underneath it, and dredging downstream on California State Parks property.
“The dredging concept that’s being recommended in this report has some benefit for flooding, but significant benefit for fish,” Nelson said. “Fish that pass from the ocean to fresh water and back face a significant obstacle right now in being able to get from the ocean to Butano Creek with the vegetation and sediment.”
Nelson stressed that these are just concepts at this juncture and that a feasible, long-term solution would take all these considerations into account.
Dredging has been recommended as a potential solution to the flooding of Pescadero Creek Road, notably in an April 2012 civil grand jury report. But the county is now setting forth the process. Supervisor Don Horsley announced at the Nov. 17 meeting that San Mateo County will apply for permits that, if approved by several agencies, could allow it to dredge the channel once or twice a year over a five-year period.
“We couldn’t justify asking for a permit without having the study of the hydrology; we would have to come up with a comprehensive plan that deals with the flooding,” Horsley said. “This report gives us the blueprint to permanently fix the road.”
Horsley said it could be a couple of years before such work could begin. The move was welcomed by the RCD and South Coast residents, Nelson said. She recalled a meeting on the flooding issue in October 2013, when county representatives were hesitant to apply for permits to dredge without a complete analysis.
“People just said, ‘Show us goodwill and apply for the permits,’ and the county is now doing exactly what people asked them to do,” she said. “It’s more progress than I’ve seen the county make on this issue during the time I’ve worked on the coast.”
The RCD plans to apply for grants that could fund the flood-plain restoration facet of the project while also working to figure out remaining details. For example, the cost of flood-plain restoration is not yet known, and the dredging price tag could rise significantly if no local disposal site for the dredge spoils could be found. The project would also cross onto private lands, particularly for the upstream component.
“The devil’s in the details,” Nelson said. “It might be a painful process for some people who want to see it done already, and it might be costly. We’re going to have to be above board in how we get this done so whatever we do is sustainable.”