The California Department of Boating and Waterways (DBW) began spraying the waterways of Discovery Bay and Bethel Island this week in the first of a series of treatments designed to manage the prolific egeria densa waterweed.

“This is a huge step in controlling the problem and providing vital feedback for handling the issue in the future,” said CSD President Kevin Graves. “It’s great news.”

The tenacious weed first caught the attention of local homeowners and officials last year when a perfect storm of temperature, water and sunlight caused the fast-growing weed – most commonly found in pet stores and home aquariums – to expand its reach, clogging area bays and waterways up and down the Delta. But because treatment for the weed costs approximately $2,000 per acre and requires a state permit, the herbicide is unavailable to the public.

Last year, County Supervisor and Discovery Bay resident Mary Piepho began advocating that the state-run agency foot the bill for treating the egeria densa in Bethel Island and Discovery Bay. She hosted a series of meetings with the DBW, Reclamation District 800 and members of Discovery Bay’s CSD, and orchestrated two town hall meetings last weekend in Discovery Bay and Bethel Island.

“I’m glad I was able to bring everyone together and move this issue forward,” said Piepho. “This is really a Delta issue, not just a community issue … We’ve received great help from federal, state and local government and we’re hoping this is a first step toward a longer course of treatment.”

According to Graves, “The Department of Boating and Waterways really stepped up and recognized the impact the egeria densa was having on the largest residential development located in the Delta. I want to thank Supervisor Mary Piepho for bringing together all the governmental agencies to accomplish what we were originally told would never happen.”

Spraying began this week on the 350 acres in Discovery Bay and approximately 100 acres in Bethel Island. Pellets filled with the non-toxic chemical fluridone are shot through a blower into the water and will continue to be administered once a week for eight to 12 weeks. Follow-up tests will be conducted daily to chart the effectiveness and safety of the treatment. Residents who see a stray pellet or two on their docks are advised to simply brush them into the water.

Because the herbicide is slow acting, residents won’t be able to spot immediate and dramatic improvement. “It is critical to remember that it will take a few weeks to see any changes,” said DBW Public Information Officer Gloria Sandoval. “And at that time, the tips of the weeds will begin to look pinkish or whitish. So we’re really urging people to leave the weeds alone and give the treatment time to do its job.”

So far, the DBW has committed to the program for only the current season.

“Treatment is just for this year, and based on the results, we’ll see what happens in the future,” said Sandoval. “Egeria densa has never been eradicated, but it can be controlled and it does react to treatment. We’re hopeful it will be effective in the treated areas.”