Agricultural water use accounting provides path for surface water use solutions

Abstract

Agricultural water demands can conflict with habitat needs in many North Coast watersheds. Understanding different water use patterns can help reduce conflict over limited supplies. We measured on-farm crop water use and conducted grower interviews to estimate the agricultural water demand in the upper Russian River and Navarro River watersheds. Annual agricultural water demand was less than 11% in the Russian River, and 2% in Navarro River, of the total annual discharge in each watershed. However, because demands are concentrated in the dry season when instream flows are at a minimum, these relatively small amounts can represent a significant constraint to stream habitat conditions. We have shared our study results in broad basin and community water resource planning efforts, including flow management of the Russian and Navarro rivers and implementation of the Sustainable Groundwater Management Act in the Ukiah Basin. Findings and recommendations from this study have influenced on-the-ground solutions to meet water demand in these watersheds, including construction of off-stream wintertime storage capacity to replace summertime stream diversions, and use of a municipal recycled water conveyance system as a replacement for summer diversions.