Making matters worse, even in relatively normal wet years, Central Valley salmon suffer from manmade drought due to competition for water with agriculture and urban residents. By and large, reservoir releases are timed to meet the needs of these groups, not those of salmon.
In 2009 the federal government implemented restrictions on some water diversion practices harmful to listed winter and spring run salmon. The restrictions were contained in what’s called a biological opinion, or biop, which required certain mitigation steps for the damage caused by federal and state water projects. The 2009 biop greatly helped restore the runs until drought hit in 2012 and gains were lost. Delta pumping restrictions meant water users with junior water rights saw cuts. The junior water rights contractors sued and lost in federal court. Undeterred, they next turned to politicians in Congress to change the laws protecting threatened and endangered wildlife. Since 2013 we’ve seen legislative efforts, one after another, to overturn or weaken established law protecting species. A fair amount of GGSA time and energy has been spent fighting off these efforts because requirements to protect threatened and endangered salmon runs also protect other salmon runs that supply the salmon fishery. They also protect many other species in the Central Valley and Delta and major parts of California’s unique natural heritage. In December of 2016 a federal bill weakening Central Valley salmon protections became law. Massive pumps divert water from the Sacramento and San Joaquin Delta for export south
GGSA’s Salmon Rebuilding Plan To identify and prioritize the problems facing Central Valley salmon, GGSA worked with fisheries biologists and state and federal fish agency experts to develop a salmon rebuilding plan. The plan currently has 27 projects that will go a long ways towards strengthening Central Valley salmon runs when implemented.
The 27 projects were selected because they rebuild both wild and hatchery salmon runs and can be implemented at early dates, mostly affected by funding availability and permit approvals. The projects call for fixes both in the Sacramento and San Joaquin rivers, their tributaries, and in the Delta. Some of the projects in the GGSA plan include:
- Adding spawning gravel and restoring rearing habitat for wild salmon the Sacramento River basin
- Changing reservoir operations that currently dewater wild salmon eggs leaving them high and dry when the flows are cut
- Improving trucking and barging practices to safely move hatchery smolts around the Delta and river hazards while also minimizing straying
- Modifying predator hotspots by eliminating predator hiding places or giving the baby salmon places to hide in predator locations
- Using pulse flows in the rivers and tributaries to move smolts and fry past predator hot spots
- Improving flows through the Delta in the critical springtime when the smolts are migrating
- Improving the archaic pump salvage system by placing the salvaged fish into recovery net pens instead of dumping them in a highly stressed condition into open predator locations
The case for rearing area restoration. Among other improvements, the salmon rebuilding plan stresses the need to restore areas along the edges of Central Valley rivers where baby salmon can safely feed, grow, and hide from predators.
Side channels featuring lower flow velocity and overhanging trees and brush where insects cluster have been largely lost in man’s effort to tame and hem in the rivers and streams.
There is good evidence that well fed baby salmon survive better than hungry, skinny, baby salmon. Streams that flow out on to remaining flood plains see higher survival of baby salmon reaching the ocean. Butte Creek, which drains into a floodplain called the Sutter Bypass, is an example of this. During the low salmon years of 2008 and 2009, salmon from Butte Creek returned at higher rates than neighboring salmon that didn’t have access to floodplains as babies. We know that many historic feeding areas along the edges of Central Valley rivers and streams used by baby salmon have been lost to human development. But many of these can be restored. Aerial photographs make clear there are many former parts of the river bed, now dried out behind dikes and levees or plugged by gravel, can be restored by moving a little earth. The greatest opportunities to restore rearing areas are in the upper parts of the Sacramento, Feather and Yuba rivers. The Sutter bypass, which is basically a flood plain currently available to Butte Creek salmon, could be made more accessible to runs from the Sacramento, Feather and Yuba rivers with minor modifications.
The Yolo Bypass west of Sacramento holds the greatest potential rearing area in the Central Valley. Its value for growing baby salmon is so high that the National Marine Fisheries Service (NMFS) are requiring state and federal water managers to modify it make it more accessible. Flood control barriers that separate the Sacramento River from the Yolo Bypass can be lowered to allow this. In addition to rich feeding grounds for juvenile salmon, the Yolo Bypass drains to the western Delta at a point safely beyond the area where the Delta pumps can pull baby salmon off their natural migration course. This provides a major benefit to baby salmon exiting the Central Valley through the bypass instead of through the Delta. The Yolo Bypass, west of the city of Sacramento
Working to Improve flows Water distribution in the Central Valley is driven partly by the needs of federally protected species and partly by the demands of water contractors who take water from state and federal water projects. These needs run mostly counter to each other. For the most part, flows and temperatures are only managed for fish when federal law requires it. For instance, federal law requires a portion of the upper Sacramento River be maintained at no more than 56 degrees from June 1 through October 1 to aid spawning winter run salmon. But too often, fall run salmon, which spawn from September through December, spawn in flows above 56 degrees, which kills their eggs. Similarly, reservoir releases have to be maintained at a steady level during that same June 1 through October 1 time period so that winter run redds remain inundated. Too often, come October 1, reservoir releases are cut drastically as agriculture demand ends for the year. This often leads to dewatering of fall run redds and massive loss of fertilized eggs. Drastic reduction of water releases from reservoirs in the fall kills salmon eggs laid in shallow water gravel bars like those seen here.
GGSA has engaged water managers and those who receive water to seek modifications to the practices that harm salmon. In years flush with water, it’s generally easier to find a common ground. In times of drought, it’s much harder.
The other major flow need by salmon on dammed rivers is strong runoff in the spring to carry the baby salmon to sea. Dams capture the natural runoff and block this critical component salmon have evolved to depend on. In very wet years there’s enough rain and snow runoff coming down streams below dams to mimic the pre-dam condition, but not so in dry years. That’s when it’s needed most. Some argue that federal requirements designed to protect Central Valley salmon came up short by not including such a requirement. Interestingly, such a requirement does exist on the Columbia and Snake rivers in Idaho, Oregon and Washington but this was only gotten after many years of salmon advocates fighting for it in the federal courts. Since this requirement went into effect in 2005, salmon stocks on the Columbia and Snake rivers have rebounded.
Some projects have been completed or are well on their way. You can read about some of the projects that have been implemented and are now aiding in salmon restoration in our Accomplishments section.