For the past few years, Avila Beach has experienced flooding in the major parking lot next to First Street and San Francisco Street. The water level has risen so much that the adjoining streets were flooded, concerning citizens and shop owners alike. County Public Works Department (CPW), which is responsible for the cross culvert running underneath Avila Beach Drive that drains the water, spent approximately $60,000 to pump flood waters out in 2015-2016 and will likely spend $50,000 this year, according the report generated by Brad Hagemann, general manager and district engineer of the Avila Beach Community Services District (CSD). In Dec. 2016, CPW, CSD and the San Luis Port Authority met to discuss the issue.
Though unsightly, the vegetation and debris in the parking lot’s culvert has little to do with the drainage issue. Hageman said that the real culprit was the sandbar that separated San Luis Obispo Creek and the Pacific Ocean.
“It’s a matter of during the summer time, the sand washes in and, if we don’t have any big storms, it can last over a winter,” said Hagemann. “During this drought, it has even been more problematic.”
With San Luis Creek cutoff from the ocean, the estuary becomes a lagoon and prohibits the drainage pipe fulfilling its purpose and builds sediment at the culvert’s exit. It becomes cost prohibitive to remove the sandbar annually due to the Environmental Protections Agency’s requirement to apply for permits and surveys. The recent storms enabled the outflow of creek water to produce enough force to punch through the sandbar.
David Flynn, deputy director of CPW explained that the development of Avila has increased the amount of runoff the area experiences. Land naturally absorbs a portion of rainwater, the excess is called runoff. If the majority of a lot of land is covered with a building this greatly reduces the land’s ability to absorb water.
“…You’ve got a tremendous amount of runoff, coming off of those building which does not have any mitigation on site, so it’s all going to run to the low spot,” said Flynn.
That low spot is the parking lot. Additionally, with the new development being built adjacent to the parking lot, water runoff will increase and possibly exacerbate the situation. Even with the sandbar cleared, Flynn estimated that the runoff from a half inch of rainfall could cause temporary flooding.
In 2015, Cannon Engineering was retained by the CPW to create a conceptual design report to provide alternate solutions.
“The recommended alternative was the installation of a permanent pumping system that would include a wet well and conveyance piping that would pump the storm water to the Front Street storm drain,” sid Hagemann in a memorandum to the CSD board. The estimate cost of the project would be $375,000 and the operational and maintenance of the pump is unknown, but is tentatively estimated around $25,000 annually.
The heart of the matter is who is going to pay for it. Hagemann brought the issue to the CSD after a meeting with the CPW and the Port Authority.
“I went back to my board and asked if the CSD was interested in doing the maintenance and they said, ‘No.’” said Hagemann.
The Port Authority had a similar stance according to Loch Dreizler, Port Authority’s facilities manager. “If you look at the property line, that drainage ditch is in our property line, but we have always felt that because the water runs off Avila proper into this drainage that it’s more of a drainage operation more than a Harbor District’s responsibility,” said Dreizler.
“I think people are interested in working through this issue” said Hagemann. “The county is leading the charge, but it’s tough for these other monopolized boards and districts to take responsibility for something that’s probably outside of our purview.”
According to Hagemann, the CPW, CSD and the Port Authority will revisit the issue in March after discussing it with their respective boards and agencies.
By Mark A. Diaz