Use it or lose it: Water pipeline project explored
North San Joaquin water official explains upcoming groundwater project
Joe Valente’s gray Chevrolet pickup truck drove down Tretheway Road in Lodi on Friday afternoon as the president of the North San Joaquin Water Conservation District Board of Directors pointed out large concrete cylinders, known as stand pumps, that provide air to a seven-mile pipeline stretching from the Mokelumne River to Pixley Creek Slough.
Installed approximately 60 years ago, the pipeline was intended to provide surface water from the river to farms in the southern part of the water district, according to Valente. Although the pipeline functioned properly for flood irrigation, it was unable to meet the farmers’ needs when they switched to drip irrigation, requiring them to tap into the groundwater supply, he explained.
“Think of it like a hose: If you don’t have anything on one end, it just floods. The next step in irrigation is like adding a sprinkler. You need pressure for water to flow through it, and the current pipeline is not able to create that pressure,” Valente said.
To address this issue, the water district board proposed the South System Groundwater Improvement Project, which would involve installing seven miles of PVC pipe as well as a new pump station. This would allow farmers in the area, primarily vineyards and cherry orchards, to utilize surface water from the Mokelumne River to irrigate their farms instead of groundwater, which Valente explained takes longer to replenish.
The board has held several public meetings since announcing the project in 2017 to solicit input from landowners whose property will be assessed based on size to help cover its cost of $18.75 million. Although the district was awarded $5.75 million in grants, they still need to raise $13 million to begin the project by 2019, or risk losing the grant money, Valente
“By 2025, we have to show the state that we’re doing something with that water, or trying to do something, or else we could lose it.” JOE VALENTE PRESIDENT, NORTH SAN JOAQUIN WATER CONSERVATION DISTRICT BOARD OF DIRECTORS
said.
As he drove to the existing pump station on the Mokelumne River, Valente outlined the three methods for installing the new pipeline that the board is exploring with help from Provost & Pritchard Consulting Group.
One option is to completely remove the existing cement pipeline and replace it with PVC, which he said would likely mean digging up many people’s land. Another method would be to install the new pipeline next to the existing pipeline, which he felt would create the same problem.
After parking his truck, Valente walked down to the river and explained the third option, known as “slip-lining,” which would involve feeding the new pipeline directly into the existing pipeline at its starting point near the river. This would mean that roadways and other land in the area would likely not need to be excavated, saving time and money and minimizing the inconvenience to landowners, he said.
“It could be a combination of all three options, it all depends on what’s the most cost-effective way to do it,” Valente said.
The project will also involve replacing the five existing pumps at the pumping station, some of which Valente said were installed in the 1960s, with a single variable-speed pump.
“If we need to max out the water flow, it can do that. If we need it to go slower, it can do that, too. It just makes the process a whole lot more efficient,” Valente said.
Another factor that motivated the board to pursue the project is the district’s water rights, Valente added. The district currently has the right to 20,000 acre-feet of water per year. Every few years, it must show the State of California that it is either utilizing that water, or has plans to use it, or it risks losing that right.
“By 2025, we have to show the state that we’re doing something with that water, or trying to do something, or else we could lose it,” Valente said.
The project has already gained the support of Steve Schwabauer, the city manager for Lodi. Schwabauer explained that the plan could benefit the entire county, whose groundwater basin is among the most overdrafted basins in California.
“I think the North San Joaquin project is good for all of San Joaquin County. San Joaquin County has one of the most overdrafted groundwater basins in the state. It’s in critical overdraft, and we have to act sooner than other basins if we plan to become sustainable in the face of a 100,000 acre-feet-per-year overdraft,” Schwabauer said.
Valente added that the City of Lodi already has a similar practice in place, pumping water through its treatment center at Lodi Lake before using it to supply the city. If approved by the water district’s voters, the project would result in even less groundwater being used during years with heavy rain, saving it for dry years.
“If we all pull water out of the same cup, it’ll get empty a lot sooner whereas if we manage that cup or bucket responsibly, it won’t run out,” Valente said.