As a best case scenario, it would take five years to eradicate zebra mussels and reopen the San Justo Reservoir for recreational use, according to a presentation by the Bureau of Reclamation at the Board of Supervisors meeting on June 25.
That is, however, if funding is approved today to implement the eradication plan by treating the reservoir and pipe system with potassium. Supervisor Jaime De La Cruz pointed out that obtaining funding takes about two years, putting the overall timeline at seven years.
Bureau of Reclamation deputy area manager Duane Stroup said that as of June 25 there was no funding to deal with the mussels. He also stated he was legally prohibited from speaking further about funding.
“It’s not an answer I like to give, but I also like my job,” Stroup said.
After securing funds, the next steps are to obtain a chemical applicators permit, issue requests for proposals and implement the eradication plan. The plan includes two years of treatment with an additional three years of monitoring to verify the mussels were eradicated.
While nine residents urged all agencies involved to find a solution so that recreation activities can resume, Hollister Councilman Marty Richman expressed serious doubts.
“I have to tell you realistically, we are never going to be on the water again in San Justo Reservoir,” Richman said. He cited decontamination requirements which state that boats must be sprayed with 155-degree water and clothes must be put into a freezer in order to kill the mussel infestation. According to this guide, equipment and cloting artifacts must be frozen for at least five hours.
“It’s a tough invasive species to get rid off. This is not easy,” Richman said.
According to the county staff report, the cost to treat the reservoir is about $3 million with an additional $100,000 per year for monitoring. San Benito County Water District deputy engineer Garrett Haertel said it would also take an additional $3.5 million to treat about 100 miles of pipes in the system.
The financial burden falls on the Bureau of Reclamation, Stroup said.
As for having a vendor operate fishing equipment at the reservoir, there remains “a very significant risk of infestation,” Stroup said. “They transfer easily and the damage that they can do is significant. We have judged to date that the best solution short of eradication is to isolate the reservoir from recreation.”
According to the United States Geological Survey, zebra mussel infestations are more common in the eastern United States. There are only two reported areas in California where zebra mussels have been found: San Justo Reservoir and Ridgemark Golf Course.
Haertel said the water district has spent over $600,000 to eradicate the mussels. He added the effort resulted only in containing the mussel population.
One of the challenges is dealing with the veligers―zebra mussels in their juvenile state―because they are small and hard to filter.
It takes between two to three weeks for zebra mussels to settle in an area as they begin to increase in size, and they can live from two to five years, according to Cary Institute of Ecosystem Studies. Zebra mussels can reproduce by their second year, with females releasing up to 1 million eggs and the males more than 200 million sperm into the water where fertilization occurs.
While the supervisors said they were frustrated, they urged the community and agencies to stay committed to finding a solution that allows residents to use the reservoir for recreation.
“It’s not ours to open,” Supervisor Anthony Botelho said. “I wish it was ours to open. We’d find a way, I think, a more streamlined way as suggested by a member of the public to work through and eradicate those mussels, but it’s not our decision. We’re just one agency that is a partner probably with a minimum of a dozen agencies that need to resolve that problem.”
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Resident urges county to work on reopening San Justo Reservoir
