WEAP
WEAP (the Water Evaluation and Adaptation Planning system) is a model-building tool for water resource planning and policy analysis that is distributed at no charge to non-profit, academic, and governmental organizations in developing countries. WEAP is used to create simulations of water demand, supply, runoff, evapotranspiration, water allocation, infiltration, crop irrigation requirements, instream flow requirements, ecosystem services, groundwater and surface storage, reservoir operations, pollution generation, treatment, discharge, and instream water quality.