A two-foot steelhead trout is not a happy fish when stuck in shallow Los Trancos Creek during dry season, Stanford University's campus biologist Alan Launer said this week.
To aid fish migration and help the school collect water more efficiently, Stanford is planning changes to the creek and its own Felt Lake, located west of Interstate 280.
As part of the three-part Steelhead Habitat Enhancement Project, a fish ladder in the creek will be replaced, among other improvements.
The fish ladder currently allows water to spill over a dam and rush downstream, according to Tom W. Zigterman, associate director of utilities at the university.
Called an Alaska Steep Pass, the ladder was designed for full, rushing bodies of water in Alaska — not Los Trancos Creek, whose flow varies wildly and sometimes slows to a trickle, Launer said.
And steelhead trout, a threatened species that travels upstream to spawn, have trouble making it up the ladder in low flows, Launer said.
Instead of spawning, fish occasionally get stuck below the ladder, then turn around and head back to the bay, he said.
"They don't want to get stuck in this dinky little creek," he said.
The current ladder works poorly when creek flow dips below three cubic feet per second; the new concrete step-pool and "weir" ladder would be easier to navigate in flows as low as half a cubic foot per second, he said.
It may even increase chances of steelhead survival by easing their journey and allowing them to spawn more readily throughout the creek, he said.
In addition to the fish ladder, the project would revamp the system by which Los Trancos water is diverted to Felt Lake, Zigterman said.
The university uses the lake, a man-made reservoir, to irrigate golf and athletic fields.
To hold extra water, the school would dig up roughly 100 acre-feet of sediment that has settled in Felt Lake since its 1920 creation, Zigterman said.
The sediment would be spread over adjacent hills with a mix of natural seeds to encourage vegetation, he said. Building the reservoir created surrounding "borrow pits," and filling them with earth will restore the land's original topography, he said.
The university would also replace its pumping station downstream at San Francisquito Creek near Junipero Serra Boulevard, he said. It would double capacity from four to eight cubic feet per second — but only during high flows, he said, noting the flow can reach hundreds of cubic feet per second.
The school would not take any more water in total from creeks than it does now, he said.
And the project includes a promise not to take water when flows dip below five cubic feet per second — meaning the university would essentially load up on water in winter and then leave creeks alone in summer and fall, he said.
That's a change from the current practice, where water is pumped with flows as low as one cubic feet per second, he said.
The project is currently under environmental review by California's Department of Fish and Game, Zigterman said.
A response should come this spring and work would begin this summer, he said.
While it dredges the reservoir, Stanford would use its wells to irrigate fields, he said.
Currently, Lake Lagunita on the university campus is at high levels because the reservoir water is being drained in anticipation of summer's work, he said.
He was not sure the exact amount being pumped, he said.
These preparations are underway because, according to Zigterman, the university expects the state to issue a mitigated negative declaration, or a clean bill of environmental health for the project.
Creek watchdog group San Francisquito Watershed Council found no problems with the proposal during meeting with Stanford representatives, according to Ryan Navratil, the council's program director.
"It appeared very much like Stanford had done their homework," he said.
The group even wrote a letter to the state agency last year expressing support, Zigterman said.
The current diversion system at Los Trancos has worked poorly since its 1995 installation, Launer said. It requires manual monitoring — or people scrambling out at 2 a.m. in the middle of a storm to insert flash boards to direct the water, he said.
The new system will be automated, he said.
The entire diversion, lake and fish project has been tangled in arguments for nearly a decade, he said.
Discussions with state agencies began in 1999, but Stanford and agencies had trouble seeing eye-to-eye on how much water should be diverted.
"Both sides were pretty obstinate, putting it mildly," he said.
Stanford ultimately agreed to many agency requests, including not to divert water during dry times, he said.
Stanford has riparian and pre-1914 appropriative water rights at its diversions, Zigterman said.