The objective is to create a hydrologic foundation for detailed assessment of human and climate impacts on stream and river flows, including the impacts of hydrologic alterations on aquatic habitats. A specific application will be to support implementation of ELOHA, the Ecological Limits of Hydrologic Alteration, a scientific framework for determining environmental flow needs for all rivers and streams throughout a very large region. During Year 1, we will model pre-development (unaltered) daily flows for 1960-2006 for every enhanced national hydrography dataset (NHDPLUSPlus) catchment within the SALCC. We will also model current condition daily flows over the same time period for at least 6 watersheds using available data on current water withdrawals and discharges, and we will assess the feasibility of modeling current conditions for the remaining portions of the SALCC. During Year 2, we will model current and potential future conditions in as much of the SALCC as is feasible, considering data availability and limitations encountered during Year 1. Future conditions will incorporate anticipated climate and land-use change and potential management strategies to address these.
