WMOST is a decision support tool that facilitates integrated water management at the local or small watershed scale. Integrated water management involves coordination across multiple programs for land, water, and related resources (stormwater, wastewater, drinking water, land conservation) to find sustainable and cost-effective solutions. WMOSTv3 has an associated theoretical documentation report as well as a detailed user guide. While version 2 only included management options related to water quantity, version 3 of WMOST also includes water quality management. Users can identify least-cost solutions to meet water quality criteria for lakes or streams/rivers, pollutant loading targets, and/or minimization of combined sewer overflows. Version 3 also includes riparian buffer zone restoration or conservation, a few agricultural BMPs, and additional stormwater best management practices, both structural, such as rain gardens and nonstructural, such as street sweeping. The Hydroprocessor, a program which formats output from watershed models such as SWAT and HSPF for input to WMOST, is also included.