Bolsa Knolls Update

Photo Credit: Balance Hydrologics, Santa Rita Creek Flood Study

Dear Friends & Neighbors,

For years, residents in Bolsa Knolls have dealt with increasingly severe flooding, often multiple times a year. More than two-and-a-half years ago, I began efforts to have the County take a serious look at how to address Little Bear/Santa Rita Creek, which runs through the area.

Much of that time has been spent developing a drainage study outlining potential solutions and costs. That study was presented to the Board of Supervisors in late March. While I have concerns with several aspects of it, it does provide a starting point for how we might better manage the creek.

One important finding is that the creek is no longer in its original alignment. At some point long ago, it was rerouted. That was long before modern construction standards existed. The result is a poorly designed channel with sharp 90-degree turns that restrict natural water flow and contribute to the flooding. Development along the creek dates to at least the 1940s, and flooding has been an issue ever since.

Conditions appear to have worsened as surrounding agricultural land shifted from grazing to row crops and strawberries. These changes increased both water runoff and sediment flowing into the creek, further compounding the problem.

The study outlines a range of potential solutions, including enlarging culverts, removing sediment at key points, managing vegetation, building upstream detention basins and clearing sediment from the creek itself. Costs range from $550,000 to $6 million. This is not a problem with a single fix. It will require a combination of approaches. One major challenge is that much of the creek runs through privately owned land. That complicates permitting, funding and implementation.

At the Board meeting, I asked staff to return within 60 days with more detailed cost estimates, potential maintenance structures such as a special district and funding strategies. I also requested a list of actions that can be taken immediately without requiring state or federal permits. Even after a decision is made, securing permits could take two years or more and there is no guarantee approval will be granted.

While the report includes sensible options, such as enlarging culverts, it falls short in its analysis of sediment removal. The study documents up to 1.5 feet of sediment buildup in some areas since 2017 yet concludes that removing it would not significantly improve flooding compared to other options. Over decades, it is likely that several feet of sediment have accumulated but that is not fully discussed. The study completely fails to address how continued sediment accumulation will affect future flooding. I believe that is a serious omission.

Sediment removal is also the most expensive option presented. The study estimates permitting costs alone could reach $2 million with project costs ranging from $1 million to $4 million. I don’t see how the flooding can be mitigated without removing decades of sediment. After that, the creek will require regular maintenance and there needs to be a process built into place to fund and perform that work. 

As always, don't hesitate to reach out to my office for assistance. You can reach us at 831-755-5022 or district2@countyofmonterey.gov.

Sincerely,

Glenn Church

District 2 Supervisor