By Todd R. Hansen
McNaughton Media
It has been a comeback year for salmon in Putah Creek.
Max Stevenson, the streamkeeper for the Lower Putah Creek Coordinating Committee and the Solano County Water Agency, estimates more than 500 fish are in the creek system.
The boards at the Los Rios Check Dam were removed in late October, and the fish have been making their way into the creek ever since.
“There are hundreds of salmon in the system and they are still coming up,” said Stevenson, who took over Jan. 10 for longtime streamkeeper Rich Marovich. “There are probably more than 500.”
That after a year in which only four fish are known to have reached the spawning redds after an unusual series of circumstances led to dozens of salmon dying due to low levels of oxygen in the water.
Heavy rains in late October 2021 dislodged loads of organic material and caused an overflow from the east levee to drain into the Yolo Bypass Wildlife Area.
When the refuge then used that water to flood rice fields for waterfowl habitat, some of that water spilled into Putah Creek, resulting in low oxygen levels. Salmon are particularly susceptible to oxygen depletion, which is a reason why cooler water temperatures are best.
The phenomenon had never been known to happen before.
This year, ironically, it is the drought that may have helped bring the fish back to Putah Creek, Stevenson said. That is because, despite the lack of rainfall, the stability of Lake Berryessa has allowed for normal water flows in the creek, and that has given a place for the salmon to go.
“That is probably one of the reasons,” said Stevenson, adding the water temperature is very good.
Officials also added in about 80 tons of gravel to build and improve the salmon spawning areas, and Stevenson said the fish have claimed the new territories and are using them for spawning.
Stevenson said the fish are easily seen from the Winters park area, and specifically from the railroad and car bridges.
“They are jumping out of the water,” he said. “So next year, we may use even more (gravel),” suggesting maybe 500 tons could be brought into the creek.
“Five hundred tons maybe would be good for five 100-foot sections,” he said.
The past practice in the creek has been to simply dig up the redd areas, loosening the existing gravel and other materials in the stream so the fish do not have to work so hard to build the spawning nests.
All the work is an effort to get the spawning numbers up to the record levels of more than 1,500 fish. Nearly 2,000 were counted in the fall of 2016.
Stevenson said to make the fishery even more healthy, the kind of channel restoration that has been completed upstream from Interstate 80 needs to be done on the 13 miles of creek downstreet from the highway.
“We need to focus on the wildlife area. (That stretch) has been channeled and gravel mined, so I would like to put it back,” Stevenson said. He said that is the next big project he hopes can be funded.
Stevenson admits he has gone through a kind of culture shock since taking the job.
“I thought I was going to be in charge of the creek, like water flow (decisions) — like in my old job on Cache Creek,” Stevenson said.
He said the culture and the funding mechanism at the Solano County Water Agency are different, and it has taken time to get used to that.
However, Stevenson said he likes the job and the work.
Stevenson came to the Solano County Water Agency from the Yolo County Flood Control and Water Conservation District.
He said he is also waiting on the latest report on the origin of the fish that have returned in past years. He said the COVID-19 pandemic has slowed things at UC Davis, but he is expecting the report sometime early in the new year.
The researchers are hoping they can show the salmon that have returned also started their lives in the creek, which in essence would mean Putah Creek would have its own race of salmon.
