Chris Caskey, The Union Democrat

A dam on the Tuolumne River might have to go through an often time-consuming and costly relicensing process in the wake of an order from a federal agency.

According to an order released last week, the Federal Energy Regulatory Commission found that the La Grange Dam must be licensed by the agency. The oldest dam on the Tuolumne River, the La Grange Dam has been in place since 1883.

The dam was first built to divert flows from the river for the Turlock and Modesto irrigation districts' canals. In the 1920s, the districts that operated the dam installed a hydropower plant, according to the FERC report. The dam also regulates the flows coming out of Don Pedro Reservoir.

"The La Grange hydroelectric project is required to be licensed," the report reads.

The FERC licensing process can be lengthy and expensive. The federal agency requires a complete environmental review of the dam and its operations, which can lead to changes in flow requirements and other new regulations.

The larger Don Pedro Dam is now in the midst of the multi-year process of renewing an existing FERC license, with costs expected to reach $25 million.

Michelle Reimers, a spokeswoman for the Turlock Irrigation District, said on Friday that a meeting was scheduled yesterday where district officials would discuss how this order could affect TID.

Melissa Williams, spokeswoman for MID, said in an e-mail that the order was in response to a request from the National Marine Fisheries Services and does not necessarily start the relicensing process yet.

"We are currently reviewing the (order) … and evaluating its findings," Williams said.

The dam, located about two miles downstream of Don Pedro, is more than 130 feet tall and about 300 feet wide, according to FERC.

The Tuolumne River Trust, a Bay Area environmental group that focuses on improving the health of the beleaguered lower section of the river, applauded the decision last week. In a written statement, the organization stated the decision could lead to changes in water flow on the Tuolumne that improve recreation and help strengthen salmon runs on the river.

"While we support a healthy ag-based economy, it doesn't have to come at the expense of a healthy Tuolumne River," Patrick Koepele, deputy executive director of the organization, stated earlier this month. "We are eager and committed to finding workable solutions that allow for both."