Operation FATFISH by Dave Eggerton Nov 26, 2018 Voices on Water A recent ACWA event jointly hosted by Region 2 and Region 4 vividly illustrated the value behind functional flows and science-based solutions for the Bay-Delta’s salmon population. Just north of Sacramento, a 19-member partnership between growers, nonprofits, water districts, and state and federal agencies plans to flood agricultural land and connect it through waterways to the Yolo Bypass and Sacramento River. This collaborative effort is the Fish Food on Floodplain Farm Fields Project, which aims to recreate seasonal floodplains that once transformed much of the Sacramento Valley into a vast freshwater inland sea providing critical habitat for fish and wildlife. A modern-day experiment proved how we can continue to recreate those historic floodplains and restore healthy salmon populations. Scientists named it Operation FATFISH, which stands for Flooding Agricultural Tracts For Improved Salmon Habitat. They compared salmon smolt reared in flooded agricultural land with smolt of the same age in the river channel. The results were stunning, as seen in this photograph from partnership member CalTrout. Smolt taken from the floodplain were twice the length and more than double in girth than the river smolt. The scientists nicknamed them “Floodplain Fatties,” and they owed their plump looks to slow-moving water rich with insect life nurtured by decaying rice straw. Sheeted across hundreds of acres, the floodwaters had acted as a giant solar panel that transferred energy into the habitat to grow bugs and feed fish. Scientists then analyzed how specifically timed reservoir releases upstream pushed food-rich floodplain water down into the Sacramento River channel within its armored banks, where smolts are typically starved for nutrients, over-exposed to predators and ill-equipped for life in the ocean. These functional, or “pulsed,” flows created a measurable wave of plankton that washed downstream and into the Bay-Delta. If we can implement this tactic on a widespread scale, we can help grow healthy salmon smolt that have a chance against predators and that can survive long enough to make it to the Pacific. A video shown during the Region 2 and 4 event envisions how this can work. Produced by River Garden Farms and available through the Northern California Water Association – both members of the partnership mentioned above – it encapsulates the potential behind this approach. The concept behind this video presents an alternative to Bay-Delta ecosystem restoration that some reflexively disregard in favor of using set percentages of unimpaired flows. It’s an example of a scalable solution that could be considered on Dec. 11 in place of the State Water Resources Control Board proposed Bay-Delta Plan update. The State Water Board’s current proposed update is to mandate a percentage of unimpaired flows by further limiting water for agricultural and urban use. In theory, this would mimic the natural hydrology as it existed 150 years ago when the Bay-Delta supported an abundant fishery. But the problem is, inflexible regulations with prescribed times and set percentages of flows ignore a rapidly changing reality on the ground and in the river. The levies, the cities and farmland that have long since replaced the marshes and tidal estuary are not going away. The mostly channelized rivers, particularly the Sacramento River, no longer resemble the natural riverine environment of the mid-19th century. But there are a number of non-flow measures, such as habitat restoration, that are critical to species survival, and these measures are working. The ability to reintegrate the floodplain through agricultural land with flexible, timed, functional flows is an important tool. It will take a lot of tools to build a Bay-Delta solution, but we’ll have to think outside the river banks to find them. That will require collaboration between everyone with a stake in the Bay-Delta ecosystem, which is virtually the entire state. Fortunately, we have examples supported by measurable proof of how this works right in front of us through the Fish Food on Floodplain Farm Fields Project and Operation FATFISH.