TID will expand water conservation project

A small reservoir near Hilmar proved its worth this year in catching excess canal flows, so the Turlock Irrigation District will more than triple its size over winter.

The district board voted 4-0 on Tuesday to spend $2.5 million to expand the reservoir, created a year ago at a cost of $2.15 million. It can now capture up to 2,550 acre-feet of water over an irrigation season, and the upcoming work will bring that to 9,000, said Matt Hazen, associate civil engineer for TID.

The 9,000 acre-feet is about 2 percent of average annual deliveries throughout the district, but it could come in handy during drought. This year, for example, they got about 40 percent of their accustomed amount. TID also faces the likelihood of reduced Tuolumne River supplies over the long term because of state and federal efforts to protect fish.

The district serves the Hilmar area via the Highline Canal, which sometimes carries more than farmers can take and spills into the Merced River. The reservoir had been part of a treatment plant for the Hilmar County Water District, then was abandoned. TID bought it last year.

The water in the reservoir is released to Laterals 7 and 8, which branch off the Highline Canal and serve the south part of the district. A separate project last winter outfitted them with high-tech controls that also help with water conservation.

TID plans to start work Tuesday on the reservoir expansion and finish in early March, before the start of the 2016 irrigation season. The reservoir surface area will increase from 7 to 25.5 acres.

The plan had included a concrete liner for the bottom, at a cost of $915,000. A board majority preferred to have no lining for now, so the district staff can see if it helps to recharge groundwater in that area.

Director Michael Frantz supported the lining during a workshop that preceded the vote. He was not present when the other board members – Charles Fernandes, Joe Alamo, Rob Santos and Ron Macedo – voted for an unlined reservoir.

This story was originally published November 24, 2015 at 6:19 PM with the headline "TID will expand water conservation project."