River fish List
Redding > At this point in the Sacramento River restoration game, one big fix will not change the outlook for endangered and threatened salmon.
Water managers gathered Wednesday at the Anderson Cottonwood Irrigation District diversion dam, to share an update on projects completed, projects planned, and projects still on the fish-wish list. The host was Northern California Water Association, which works with numerous water supply districts in Northern California.
The Sacramento River has four distinct salmon migrations, when fish leave the ocean and migrate up the river to spawn.
There are more than a few essentials for salmon survival including temperatures at or below 56 degrees when eggs hatch, areas to feed, places to hide from predators, and places to rest from strong currents. The river can be a “gauntlet” of obstacles that have contributed to the relatively low numbers of salmon we see today, Vogel explained.
The past years with severe drought in California certainly has not helped.
In 1992, the Central Valley Project Improvement Act ushered in the “era of the fish screen, ” explained Todd Manley, NCWA’s director of government relations. The screens prevent fish from swimming or being sucked into irrigation canals, and over the past 20-plus years about $600 million has been spent on fish screens covering almost all the major diversions along the river.
Two major fish screen projects remain and should be completed by 2018, he said. With those projects winding down, other projects will take center stage.
During the presentations Wednesday, Vogel explained the process of spawning, where female fish create a depression in the gravel with their back fins, and lay eggs. Male fish are close by to fertilize the eggs, which the female then loosely covers with gravel.
For this critical stage in the salmon life cycle, the eggs need the right kind of gravel. The problem is that dams have disrupted the natural cycle of gravel distribution. In some area, the river would be just right for spawning, except that the gravel is nowhere to be seen.
Vogel estimated that about 75, 000 cubic tons of gravel is lost from the river each year, and needs to be replaced in an ongoing way.
The river is a perilous place for young salmon, and side channels are an important place for young fish to beef up for the journey ahead.
Vogel’s list encouraged the construction of side channels, and several have already been completed. Again, Glenn-Colusa Irrigation District, for example, used big equipment to create a channel known as Painter’s Riffle.
The location of the project is in Redding, quite a distance from Glenn-Colusa’s water service area. However, the fish habitat and the need for improvements is all connected, said David Guy, president of NCWA.
In the future, there will be projects in the delta that are funded by agencies hundreds of miles away, Guy explained. But they all add to the overall goal of restoring fish habitat.
The projects have contributed to partnerships built between water districts and fish agencies, Guy said. Those agencies oversee and approve projects. Those same districts also have worked with Vogel in development of the list of projects for the future.