The Russian River, Preparing for Too Much and Too Little

In the Russian River watershed of Northern California, water managers and users cope with drought at the same time as they must prepare for floods. This is because, in the Russian River, most droughts are ended with very wet months and even floods, and 81% of the year-to-year variance of precipitation between drought and wet periods can be attributed to largest (90th percentile) storms. Many of these storms are the result of landfalling atmospheric rivers (ARs) which vary in number and intensity year to year. Climate model projections vary, but there is a loose consensus that, by the second half of the 21st Century, large storms reaching the coast of California may become stronger while droughts throughout the southwest may become longer and more severe. As such, decision makers in the Russian River must plan for future conditions that are at least as wildly fluctuating as the current regime but possibly (maybe even, likely) more extreme. The current drought in California provides examples of how different sectors adapt to improve their resilience to drought, even while preparing for floods. A major multi-agency effort in the region is assessing the use of forecast information in reservoir operations (FIRO, forecast informed reservoir operations) to allow the storage of more water from winter storms in Lake Mendocino without increasing flood risk. Recent research has shown the importance of soil moisture information to understanding the impact a storm will have on run-off to reservoirs, especially during a drought. Also, the agriculture sector in the region is building ponds that fill during floods to enhance sources of supply during droughts. By partnering with Sonoma County Water Agency we have been able to engage with a diverse stakeholders of the region, educating them on potential future flood and drought relations while learning what they are doing to improve resilience.