A California county’s main water source just got cut off

Tens of thousands of people in Tuolumne County are being asked to use as little water as possible after water delivery to the region was cut off by last week’s snowstorm.

The Main Tuolumne Canal, a series of canals and flumes that brings water through the Sierra foothills to Sonora and other communities along Highway 108, was battered by heavy snow and fallen trees, prompting its temporary closure. The canal is the main source of drinking water for 90% of Tuolumne County’s roughly 50,000 residents.

While repairs to the canal are made, the Tuolumne Utilities District will provide water from its limited supplies in storage and at groundwater wells. There is no estimated timeline for when the canal will be fixed. The utility district did not specify how long the current supplies would last but officials expect to have enough for the duration of the repairs.

“We do not anticipate anyone running out of water,” said Abby Parcon, human resources and safety director at the Tuolumne Utilities District. “That’s not a promise, but we feel pretty confident.”

The water supplier, on its website, urged its customers to conserve water “to ensure there is enough for drinking, basic sanitation and fire protection.”

The 14-mile Main Tuolumne Canal, which runs from Lyons Reservoir to the Phoenix Penstock, is operated by Pacific Gas & Electric Co. as part of its hydroelectric operations on the South Fork Stanislaus River. The delivery line traces its roots to the Gold Rush, with some of the water still hoisted by wooden trestles and flowing through open-air ditches.

Several sections of the line need repair, according to PG&E, which counted more than 200 trees striking the canal and as much as four feet of snow weighing it down during aerial surveys of the line.

PG&E officials began reducing flows in the canal on Feb. 17 and later fully shut it down, fearing the line’s waters would back up and overflow.

As of Tuesday, about 75 people were involved in PG&E’s effort to clear trees and snow and to repair the damage. On Wednesday, helicopters began flying materials to the more remote areas where fixes were needed.

“Damage is significant, weather and access continue to be issues and we’re working against a deadline,” Sam Garcia, the incident commander in charge of the work, said over the weekend. “But we’re gathering the right people and the right tools, and we have an unwavering focus on safety making these needed repairs.”