The Turlock Irrigation District has completed a small reservoir that conserves water on part of its canal system.

District leaders gathered at the site Tuesday to celebrate the $10 million project. It can handle excess Tuolumne River water on the Ceres Main Canal and a branch known as Lower Lateral 3.

The reservoir is expected to save up to 10,000 acre-feet of water per year, which is only 1.5 % of TID’s typical deliveries. Officials said it is worthwhile nonetheless amid increasing droughts and state efforts to devote more river water to fish.

“This shows that TID is always at the cutting edge of trying to do the best we can,” board President Ron Macedo said.

This is the district’s second such project, known as a regulating reservoir. The first was built in the Hilmar area in 2016. The Modesto Irrigation District, which also diverts the Tuolumne, completed a similar project near Empire.

Old canals have open ends

Both districts built their canals in the early 1900s. The water flows by gravity to the end of each branch, then spills into downstream river stretches. The volume must be high enough to reach the last farmer on each branch, so water is sometimes wasted.

TID’s new reservoir can hold up to 220 acre-feet, released downstream as needed. That’s about 0.01% of the capacity of Don Pedro Reservoir, the main storage for TID and MID. An acre-foot is enough water to cover one acre a foot deep.

The project got a $2 million grant from the U.S. Bureau of Reclamation, which is involved in irrigation around the West. TID covered the other $8 million.

The reservoir started taking in canal water Aug. 2 and was full nine days later, said Matt Hazen, the senior civil engineer who oversaw the project. It includes pumps that put water back into the canals.

TID purchased the 36-acre site from an almond grower whose trees were near the end of their productive lives. It is about a quarter-mile south of Keyes Road between Moffett and Esmar roads.

The Ceres Main Canal starts at Turlock Lake and runs past Hickman and the city of Ceres on its way to farmland in the northwest part of TID’s water service area.

The district’s other regulating reservoir is along the Highline Canal and Lateral 8 in the Hilmar area. It is in early planning for a third project on a lateral southwest of the city of Turlock.

Board member Michael Frantz said these projects are especially helpful when drought forces TID to reduce deliveries. Farmers along the most distant stretches got nothing at times, he said.

Site also will test solar panel idea

The Ceres Main project site will also host a demonstration of the idea of placing solar panels atop canals. TID got a $20 million state grant last year in a partnership with UC Merced and other entities.

They will examine whether the panels can efficiently supply the district’s electrical customers while also reducing evaporation. A canal stretch east of Hickman also is involved.

Panel installation could start in November and take about a year, said Tou Her, assistant general manager for water resources at TID.