Fish screen project well under way
Jonathan Partridge
Patterson Irrigator
03/17/2011
The short stretch of Old Las Palmas Avenue just east of the San Joaquin River is traditionally a quiet domain, attracting a handful of fishers and occasionally folks traveling to the River Oak Arena.
But the area swarms with activity these days, as a construction crew from San Francisco-based Proven Management builds a multimillion-dollar screen to keep Chinook salmon and threatened steelhead out of Patterson Irrigation District’s pumps.
The $13 million fish screen is about halfway complete and is slated to open before July 1.
“It’s one of the largest projects the district has ever undertaken,” said Peter Rietkerk, general manager of Patterson Irrigation District.
The gargantuan concrete structure will divert fish from the irrigation district’s pumps, where they could be crushed. It also should help the district retain access to its historic water rights as state and federal officials aim to restore the San Joaquin River as a salmon run.
In addition to a 10-panel screen that will block the fish from being entrained in the pumps, the natural velocity of the San Joaquin River should prevent them from getting stuck, Rietkerk said. Though the screen itself is 30 feet tall, a good portion of it is underwater.
“It’s a big structure — it’s a pretty big undertaking,” Rietkerk said. “It’s tough to get a perspective of it when you’re looking at the plans.”
Construction work started in the summer, and an old pump station at the site was demolished in the fall. In addition to building the fish screen, workers will build a new pump station in the old one’s place — all part of the $13 million price tag.
The project, which has been in the planning stages since 2003, was expected to cost about $16 million as recently as 2006. However, reduced construction expenses amid the dour economy have helped lower the cost by about $3 million.
Though the pump station will not be functional until July, the district plans to have a temporary bypass pump system up and running by April.
Footing about half the bill is the U.S. Bureau of Reclamation, which oversees a series of water projects, including federal conveyance systems, that provide irrigation water on the West Side. The state Department of Fish and Game will pay for about 40 percent, and the local irrigation district will take care of the remainder.
Getting the project up and running has proved to be quite a challenge, said John M. Azevedo, a dairyman and field crop grower who has sat on the Patterson Irrigation District board for 18 years
“It’s a real long, long process, and then you have to find the funding,” he said.
The fish screen will be the first of its type in the area since the Tracy-based Banta-Carbona Irrigation District created a similar screen in 2002.
Banta-Carbona’s board of directors became interested in the idea as a precautionary measure after the Anderson-Cottonwood Irrigation District south of Redding had to shut down temporarily in 1994 because of an environmental lawsuit.
The irrigation district has been happy with the investment, general manager David Weisenberger said, noting that it helps keep both Delta smelt and fall-run Chinook salmon away from the district’s pumps.
“It’s in excellent condition,” Weisenberger said. “It’s operating flawlessly.”
While Delta smelt do not travel as far south as the Patterson area, local irrigation districts that divert water from the San Joaquin River will have plenty of Chinook salmon swimming by after they are reintroduced the river by Dec. 31, 2012.
Those efforts follow a settlement reached in October 2006 among water contractors, environmental groups and state and federal agencies to help restore and maintain fish populations near the San Joaquin River below Friant Dam near Fresno.
While that agreement has not specifically required irrigation districts in the Patterson area to install fish screens, Azevedo noted that the Chinook salmon is considered a threatened species by the federal government.
“If you suck one of those in the pumps, they’ll shut them off,” Azevedo said.
