Water Storage Investment Program Technical Reference details the methodology for quantifying the co-benefits or adverse impacts of water storage projects under California’s Water Storage Investment Program (WSIP). The report outlines methods for quantification of various co-benefits and adverse impacts, providing guidance on defining future site conditions, calculating physical changes, monetizing project benefits and costs, comparing benefits and costs, properly allocating costs to beneficiaries, determining cost-effectiveness and public-benefit ratio, and evaluating sources of uncertainty. Projects that quantify public benefits following these methodologies are eligible for California state bond funding to pay for the public benefits.