California's Water: Living with Nature
Whether it’s improving salmon habitat or preventing the spread of invasive species, environmental stewardship is a top priority for public water agencies throughout the state. From one end of the state to the other, water agencies are partnering with other organizations to invest dollars and resources in efforts to protect species and ecosystems.
This segment focuses on innovative approaches to restoring habitat and addressing invasive species. Huell visits two Northern California locations – Butte Creek and Clear Lake – to view majestic spring-run Chinook salmon in a restored stretch of habitat and see what water agencies and wildlife officials are doing to keep destructive quagga mussels out of lakes and reservoirs.
Salmon populations in California and Pacific Coast states have plummeted in recent years. Butte Creek in the Northern Sacramento Valley is one of only four Sacramento River tributaries with remaining populations of spring-run Chinook salmon, listed under the federal Endangered Species Act. The spring run dwindled to just hundreds of returning adults during the drought years in the early 1990s.
To restore the salmon populations, Western Canal Water District, farmers, state and federal fishery experts and environmental interests worked together on a $9.1 million project to remove four diversion dams, build fish ladders and insert numerous screens to keep salmon out of water diversion pipes. With the dam structures removed, approximately 25 miles of Butte Creek was restored to free, unimpeded flow.
Completed in 1998, the project’s results have been easily measurable. In 1987, just 14 spring-run Chinook salmon returned to Butte Creek to spawn. Today, that number is between 5,000 and 8,000.
In a different aspect of living with nature, water agencies are also dealing with quagga mussels, an invasive species that can clog pipes and water intakes and wreak havoc on local ecosystems.
Introduced to the U.S. from Europe in the 1980s, quagga mussels were first discovered in the Great Lakes, where their cousin, the zebra mussel, had already become infamous for its destructive effects on ecosystems, drinking water and the environment. They have since spread to several reservoirs in California by hitchhiking on boats traveling across the country.
Although they range in size from microscopic to the size of a fingernail, they are prolific and attach themselves to hard and soft surfaces, including native fish and mussels, agencies’ underwater equipment and boats, rafts and other recreational equipment. With no natural predators, quagga infestation is usually controlled by installing feed lines for chlorine or potassium permanganate, which kills larvae and adult mussels.
Metropolitan Water District of Southern California is spending millions of dollars to control quagga mussel populations detected in the Colorado River Aqueduct, including employing dozens of scuba divers full-time to scrape colonies of quaggas off underwater equipment. East Bay Municipal Utility District is spending $2 million this year in prevention efforts. Agencies are also using specially trained dogs to inspect boats at popular water bodies such as Clear Lake to prevent further spread of the mussels. The dogs can conduct inspections in a fraction of the time it would take a human.