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Dam Demo Frees Fish
Dams are coming down right and left on Butte and Battle Creeks, two Sacramento tributaries at the heart of the state's crusade to bring back the salmon.
Most of the recent headlines herald the planned demolition of five PG&E dams on Battle's two forks and tributaries to begin in early 2000. The demo project, along with the retrofit of three other dams with fish screens, is the product of a much-touted agreement between conservation groups, CalFed, PG&E and private landowners. The result will not only be restoration of 42 miles of salmon spawning grounds, but more importantly more water for fish, according to Cal Fish & Game's Harry Rectenwald.
"Everybody thinks its a dam story," he says, "But flows are really the story. It's when you take the minimum required flows of 3 cubic feet per second and increase them to 40-50 cfs that you get restoration." Pre-dam base flows were around 120 cfs.
Tinkering with Butte Creek's hydro-hardware isn't going to produce a statewide blackout either. "These dams are little dinky things compared to hydro systems on nearby rivers or the future power gains we'll see with some of the proposed CalFed reservoir expansion projects," says Rectenwald. Removal of Battle Creek's dams represents a loss of enough electricity to power about 40,000 homes. Keeping them intact, but adding screens and ladders for the fish, would have been prohibitively costly.
Costs to hatchery fish vying for space in the soon-to-be-freed stretches of creek are less clear. Biologists and managers are concerned that fish from the federal hatchery, which sits just downstream of the decommissioned dams, could breed with native wild fish. While the health and genetic integrity of the different fish is a concern, the real problem may be more one of pure biomass in the lower creek: "They load the stream with fall-run hatchery product, so some years you've got up to 90,000 fish where 5,000 could ordinarily spawn," says Rectenwald. "Remember that this hatchery was designed to compensate for the loss of 100 miles of a river - and it's on a stream."
Managers currently install a barrier in the creek to keep the hatchery fish from swimming upstream and prevent interbreeding. The dam removal/stream restoration project really targets winter- and spring-run salmon as well as steelhead, all of which move through the stream at different times than the fall-run. "It can become a traffic problem, though, when 12 million hatchery smolts are released on top of the wild juvenile salmon that are rearing in the stream."
No hatchery conflicts cloud the rosy restoration picture on Butte Creek to the south, however. Five dams have already come down in the middle reaches of this creek, most owned by rice farmers. Now stakeholders in the lower watershed are completing studies on removing 8-10 fairly large dams and looking for funding to build 40-50 new fish screens.
Last year, biologists counted a record 20,000 spring-run salmon returning to Butte Creek to spawn. While Cal Fish & Game's Paul Ward is hesitant to directly attribute the good numbers to dam deconstruction, especially since last year was a wet year, he says the creek's freer flows can only be helping. (During some years less than 50 fish turned up.) Butte has been getting better flows for fish on and off since the early 1990s as part of dam relicensing agreements, and the recent swell in salmon may be in part attributable to those increases. Dam or no, wild fish or human-hatched, Californians can always count on the real issue in any riverine restoration debate being water.
Contact: Harry Rectenwald (530)225-2368 or Paul Ward (530)895-5015
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