26 September 8 , 2023 VOL . 42 • ISS . 13

utte Creek , a tributary of the

Sacramento River that is the last stronghold for endangered wild spring-run Chinook salmon in the Central Valley , has seen a number of die offs of endangered spring-run Chinook salmon in recent years , including the estimated 19,773 out of 21,580 salmon that perished before spawning in 2021 . Disaster struck the creek again after a plume of sediment rushed down the hillside from a breach in a PG & E canal starting around 9:00 p . m . on Wednesday , August 9 . As a consequence , the waters of the creek flowed a yellowish brown and orange color from the Sierra / Cascade foothills for 20 miles into the Sacramento Valley . PG & E employees at around 6:30 a . m . on August 10 first discovered the failure of a flume that carries water from Upper Butte Creek to DeSabla Reservoir and then down to the DeSabla Powerhouse , where it mixes with water from the West Branch of the Feather River . They shut off the water to the canal after finding the hole in the canal . The sediment spill takes place as the stream is seeing the worst run of spring-run Chinook in 26 years . On Monday , August 14 , the first photos of dead trout and frogs on Butte Creek began to come in . Peter Tira , information officer for the California Department of Fish and Wildlife , reported that “ the event is now under an active CDFW law enforcement investigation .” He also said one salmon carcass has been reported by CDFW staff in the Helltown area of the creek . “ Some dead trout were found in the creek ,” he said . “ But the thinking is they came from the canal and not the creek itself .” In three days of snorkel surveys this year , CDFW personnel found only 120 spring-run Chinook in the creek , but there was limited visibility at the time , Tina noted . The sediment release was dissipating at press time , but it has left an extensive layer of sediment of silt and clay throughout the creek bed . In fact , local farmers shut off diversions because they didn ’ t want the water going into their fields . ” The very small population of Butte Creek spring-run Chinook salmon has taken a very big hit ,” Allen Harthorn , executive director of Friends of Butte Creek , reported on August 10 . “ With only around 500 returning adults this year , they have been huddled upstream in deep pools .”

“ Is this any way to treat a watershed , one that harbors the iconic Butte Creek spring run ? Our run is in trouble as it is . This is an insult to all the collective efforts of the agencies , farmers and other water users , conservation and recreation groups to restore these fish ,” he stated . “ When the canal failed , all of the water flowing in the canal came flowing down a forested hillside for more than 500 feet to the creek ,” noted Harthorn . “ This quite likely caused major landslides from the looks of what we ’ re seeing . The shot gun gates that are radio controlled can be triggered to open and release all of the water in the flume . When they do that , water pours down multiple bare hillsides .” According to Harthorn , a graph from the Department of Water Resources showing Butte Creek flow from the gauge near the covered bridge on Honey Run Road shows a 40 cfs drop in flow while the PG & E landslide blocked the creek . “ At 4 pm , the flow jumped up 30 cfs in 1 hour after the debris dam broke . It was midnight before the sediment showed up at the gauge ,” he pointed out . He noted that staff from the regional water boards , CDFW , other agencies and PG & E had “ all hands on deck ” trying to stabilize the hillside . The breach in the Butte Canal , which follows the canyon wall and empties into Desabla Reservoir , occurred about 5 miles below the Butte Head Dam on Upper Butte Creek . “ We ’ re still investigating the cause of the failure – there ’ s a hole in the canal lining ,” said Paul Moreno , marketing and communications principal at PG & E . “ The water ran down the hillside , mixed with dirt and created turbidity in Butte Creek .” An investigator from PG & E then shut the water off in the canal . “ We noticed the turbidity in the creek at DeSabla , notified agencies about the breach and turbidity , and used sandbags and plastic sheeting to prevent water from going into the breach ,” he stated . “ We have turbidity monitors on the creek ; the data shows that the turbidity is subsiding .” On Monday , Aug . 14 , PG & E used a helicopter to evaluate the slump / sediment pile at Butte Creek , according to Moreno . “ At that time , we observed no turbidity entering the creek from the soil slump and we believe the sediment pile has stabilized ,” he said . “ Nonetheless , PG & E is evaluating appropriate next steps with respect to the sediment pile in consultation with agencies . The area is steep and remote , making access and the ability to bring in tools and materials a challenge .” “ Even under normal conditions , there is some salmon mortality in the creek during the holding period as these fish have made the arduous journey from the ocean and some do not survive to spawning season ,” he added . He noted that a survey by California Department of Fish and Wildlife is needed to determine the effect of the breach compared to natural conditions . CDFW conducts salmon snorkel surveys to count the live and dead salmon in Butte Creek throughout the summer holding period . “ Once spawning season begins in mid-September these snorkel counts are replaced with carcass surveys . Even under normal conditions , there is some salmon mortality in the creek during the holding period as these fish have made the arduous journey from the ocean and some do not survive to spawning season ,” he stated . Over the weekend ( Aug . 12-13 ) crews repaired the breach with fill and concrete , which needs a few days to cure . “ While the canal is dewatered , PG & E is taking the opportunity to thoroughly inspect and evaluate the canal . At this time , we do not have a date or estimate as to when the canal will return to service with water flowing ,” he continued . “ PG & E ’ s DeSabla-Centerville Project provides additional and cool water from the West Branch of the Feather River which supplements the natural flows in Butte Creek , meaning there is more water than otherwise would be in the creek with only the natural flows ,” he concluded . The breach in the canal couldn ’ t come at a worse time for Butte Creek ’ s struggling spring-run Chinooks . An estimated 19,773 out of the more than 21,580 spring run Chinook salmon total that returned to spawn in the Butte County stream in 2021 perished before spawning , according to a CDFW report , Only an estimated 1,807 adults survived to spawn in a year with a record return of fish , The fish perished from disease in the crowded , warm water conditions on the creek that developed before PG & E released colder water into the creek , under pressure from conservationists and anglers . They released

By Dan Bacher

cold water from Phillbrook Reservoir per their operating plan , but with a 24 hour delay due to miscommunication , according to Harthorn . Now this year , when a small number of fish is returning to spawn , nobody knows how many of these fish will survive to spawn . “ The damage will take weeks to assess but needless to say , millions of micro and macro organisms will suffer and many will die ,” said Harthorn .’ “ This is just another example of why we need to get rid of the current hydroelectric system on Butte Creek and turn it into a fisheries enhancement project ,” concluded Harthorn . “ The upper section of Butte Creek above Centerville Head Dam is prime spring Chinook habitat , but migration upstream is blocked by the dam and dewatered by the hydroelectric project . If this canal was retired , there would be 60-80 cfs of cold water in this section and lots of room for spring Chinooks .” Butte Creek has the largest self-sustaining , naturally spawning , wild population of spring chinook salmon in the Central Valley . In addition , Butte Creek is home to a wild population of rainbow trout and anadromous steelhead . The spring Chinook is one of four runs of salmon on the Sacramento River , including the spring , fall , late fall and winter runs . The spring and winter runs are listed under the federal Endangered Species Act and the California Endangered Species Act . While anglers target fall run and late fall run Chinooks on the Sacramento River and tributaries in years when the salmon season is open , they have been prohibited from fishing for the spring and winter-run fish for three decades . This year recreational and commercial salmon fishing is closed on the ocean in all of California and most of Oregon due to the collapse of the Sacramento River and Klamath / Trinity River Basin fall-run chinook populations . Recreational fishing in the Sacramento and Klamath River watersheds is completely closed , while tribal fisheries on the Klamath and Trinity rivers are severely restricted . According to fish advocates and scientists , the low numbers of fall-run Chinook salmon returning to the Sacramento and Klamath River watersheds are the result of poor water and fishery management by the state and federal governments during a drought .