Unauthorized Napa River Diversion Cited by State Water Board

A multi-year extensive investigation into unauthorized water diverters on California’s North Coast has been concluded after more than 350 letters were sent to property owners notifying them of the need to have a water right. Property owners were offered an opportunity to submit a corrective action plan.

Of the 350 letters sent 11 provided no response to the Division of Water Rights notice. All other property owners’ lacking the appropriate water rights were resolved through settlements, default judgements or enforcement actions.

The last of the enforcement actions was recently resolved when the State Water Resources Control Board took action against a Napa County property owner for unauthorized diversion of water from tributaries to the Napa River. A $75,000 fine and a cease and desist order have been imposed against the Stornetta Family Trust for diverting water without the proper permit into a 24-acre-foot reservoir on its property, located between the cities of Napa and Sonoma on Highway 12.

The Administrative Civil Liability fine was calculated based on the amount of water diverted over time, the economic benefit gained, risk of injury to other legal users, likelihood of harm to public trust resources and the limited corrective action taken by the property owner in response to the notification of the enforcement actions. However, if the corrective actions in the order are complied with by the specified deadlines, $45,000 will be suspended and released.

The state’s investigation of the Stornetta property included an on-site inspection verifying that an unauthorized diversion into a 24-acre-foot reservoir was taking place. The water taken is from an unnamed stream tributary to Huichica Creek, which feeds into Napa Slough and then Napa River, eventually emptying into San Pablo Bay in Napa County.

“The State’s water rights system is essential to managing water use, protecting other water right holders and the environment,” said Cris Carrigan, director of the Office of Enforcement at the State Water Board. “The board’s action sends a strong message to unauthorized diverters who choose to ignore notifications from the State Water Board.”

The State Water Board launch the North Coast investigation in order to bring unauthorized diverters into compliance with the water rights system, which requires water use reporting and gives the state a better understanding of where and how much water is being used. The investigation included analysis of aerial photographs, topographic maps, Geographic Information System (GIS) data and on-site inspections to identify potentially unauthorized dams and reservoirs in Marin, Mendocino, Napa, Sonoma and portions of Humboldt counties. Bringing unauthorized diverters into the water rights system also helps protect public trust resources like threatened or endangered salmon and steelhead by regulating previously unregulated facilities.