Nature-based solutions will also help reduce flood risk
Press release from the State Water Resources Control Board:
The State Water Resources Control Board and the Twain Harte Community Services District recently celebrated the completion of a stormwater project that uses nature-based solutions to protect water quality and reduce the flood risk for disadvantaged communities in Tuolumne County. The project was funded in part by a $3.7 million grant from the State Water Board’s Stormwater Grant Program, which administers funding from Proposition 1.
Stormwater improvements at four separate sites, including a 5,000-gallon rain tank at an elementary school and a rain garden at a new community park, will help keep sediment, nutrients and heavy metals out of Twain Harte Creek and Phoenix Lake, primary sources of drinking water for several disadvantaged communities including Twain Harte, Sonora, Jamestown and Columbia.
“This is a great example of a low-impact, nature-based stormwater project that can produce benefits for water quality, flood control and even recreation,” said Joe Karkoski, deputy director of the State Water Board’s Division of Financial Assistance. “The Twain Harte project was the ideal candidate for support from the Stormwater Grant Program, which focuses on changing the perception of stormwater as a contaminant source into a valuable resource.”
Located in the Tuolumne River watershed, the collaborative project replaced outdated storm drains, installed innovative stormwater capture technology, and created bioswales – vegetated, shallow depressions that capture, treat and infiltrate stormwater runoff – and other permeable surfaces to slow and capture runoff.
The community of Twain Harte often experiences flooding events during periods of heavy rain or snowmelt. Historically, these events were worsened by a mixture of factors: a high-water table, aging stormwater infrastructure, steep topography, and wide parking lots and other impervious surfaces. These flooding events move excess sediment and pollutants into Twain Harte Creek, which is on the state’s list of impaired or threatened waters.
Since 2019, the board has provided more than $28 million in assistance to various projects in Tuolumne County, including $8.6 million for drinking water, $16 million for wastewater management and $3.7 million for stormwater projects.
“This project is like a dream come true,” said Twain Harte Community Services District General Manager Tom Trott. “With the State Water Board’s assistance, we are boosting water quality, reducing flood risk and transforming paved areas into traditional landscapes accessible to all.”
The project was funded by the Stormwater Grant Program, which administers $200 million from Proposition 1. Approved by voters in 2014, Proposition 1 authorized $7.5 billion in general obligation bonds for water projects including surface and groundwater storage, ecosystem and watershed protection and restoration, and drinking water protection. Since 2014, $168 million in Proposition 1 funding has been committed to stormwater projects around the state.
More information about the board’s Division of Financial Assistance can be found on its website.
The State Water Board’s mission is to preserve, enhance and restore the quality of California’s water resources and drinking water for the protection of the environment, public health and all beneficial uses, and to ensure proper resource allocation and efficient use for the benefit of present and future generations.
