March 10 Water Workshop revealed uncertainties in water supply in this 3rd year of historic drought
March 25, 2022
Sonoma County is facing a historic drought emergency. Experts now believe that the new normal are the conditions described by Supervisor Rabbitt – climate driven “Weather Whiplash,” illustrated by the 2019 floods followed by the 2020-22 drought. Coupled with higher temperatures, we are also looking at increased severity of drought, flood and fire damage, according to FEMA forecasts. It is with this backdrop that the Sonoma Water Agency has begun a series of Drought Town Halls, the first of which was hosted on March 10th.
Note: Sonoma Water (Agency) manages the storage and distribution of water to 600,000 residential and commercial users in the County’s urban areas as well as northern Marin. As shown in the Agency’s Current Water Supply Level Chart, reservoir storage levels are about 60%. Water right withdrawals from lakes Sonoma and Mendocino and the Russian River are managed by the State.
It was clear during the Townhall that both Sonoma Water and State agencies know Sonoma County has a water supply problem. During the Workshop, speakers discussed many proposals on ensuring water sufficiency through the summer and fall months - ranging from the Russian River aquifer recharge program to a likely reinstatement of curtailments this spring. This urgent situation was confirmed in early April, when Senator McGuire announced the State authorization of $93 million in grants for water and drought infrastructure projects for the North Bay.
As mentioned multiple times in the discussion, there is no way of knowing when this drought will end. And while we’ve found ways to conserve water in our urban districts, we’re entering the summer with critically low water levels throughout the Russian River Watershed, which barely recharged even after the early winter storms.
A core issue is that our water management analyses and the models relied on, both for surface and groundwater supplies, are woefully out of date. They are based on a 15-year-old General Plan Environmental Impact Report (EIR) which broadly relied on historic assumptions about runoff, groundwater recharge, and rainfall. The difference is compounded by the fact that our models do not account for how climate change is impacting water availability.
The New York Times article by Dr. Schwartz, a lead California scientist, warns that the western states are already in the worst drought in 1,200 years. Changes in precipitation patterns, such as “Weather Whiplash” and the impacts of wildfire on soil structure, have altered how rainwater percolates to groundwater, with changes in runoff patterns reducing the water retention ability of our watersheds.
Sonoma County’s recent wildfires, rainfall patterns, increased temperature levels, and desiccating wind events are very different from historical data. This will mean not only near term short falls in water supply, but a need for a broader reckoning with reduced water availability in the coming decades.
It is, therefore, even more worrisome that we’re relying on these outdated water models to inform our assessment of the water demand that our watersheds can sustain. We need a comprehensive update to Sonoma County’s water models and water availability studies, taking these new long term realities into account. In this way the 2022-23 General Plan Update process, as well as on-going Environmental Impact Reports that rely on these analyses will have realistic water-related Baseline Analyses and not optimistic expectations of reverting to baselines of the last century . Water is a public trust resource that must be protected.