Does the County's Water Baseline Analysis include its affordable housing commitments?

Sonoma County must comply with State mandates to identify locations for new housing in compliance with its Regional Housing Needs Allocation (RHNA). This is a known use that must be included in the Baseline Analysis. 

The March 10^th Drought Townhall hosted by Water Sonoma did not identify measures being taken by Sonoma Water to address the increase in demand from new housing. In addition to uncertain future water supplies, Sonoma County must plan for new water demand from State mandated residential development for 10,680 additional housing units to address low to moderate income housing needs, and include this water demand in the Baseline. 

Unfortunately, Permit Sonoma lost their appeal to the State requesting a reduction or reallocation of unincorporated Sonoma County’s housing requirements to urban centers, with one factor being restrictions of water supply. This appeal was supported by community and environmental groups given our policy of city-centered growth, and zoning designed to protect agriculture and open space. 

Overall, the State mandated residential units, both in city centers and in rural Sonoma County could put an additional 1.4 to 1.9 billion gallons/year demand on Sonoma County’s municipal water systems and groundwater supplies.  This back of the envelope assessment includes the the Sonoma County RHNA numbers, USGS calculations for urban-related housing (from the December, 2021 Gazette article, “The Water Footprint of Wine” ), and  assumptions for the needs of rural single family homes (from the 2021 Napa Economic Study). 

State mandated housing must be accounted for in water-related Baseline Analyses for surface and groundwater supplies before other water-intensive industries are factored in. The County will not be able to avoid or reduce this increased demand and building sustainability assessments with an artificially low baseline could cause widespread shortages down the line.