An important strategy for reducing summer/fall dry season water extraction from streams and alluvial wells is the development of alternative water sources and construction of water storage. In northern California’s Mediterranean climate there are well-defined rainy winter and dry summer seasons. Extracting water during the winter rainy season when it is abundant and storing it for summer use eliminates the impact of human activities during times of low flow. For example, water can be diverted from a stream during winter high flows and put into storage, although this practice generally requires an appropriative water right. A critical aspect of this type of project is to develop an accurate estimate of the dry season water demand so that the project that is eventually constructed provides sufficient storage to meet that demand and allow for potential future increases in water use.