Technical Abstract: A new computer model has been developed and evaluated to describe the hydrology of wetlands and ponds which have farm fields and agricultural watersheds as their water source. Wetland predictions include daily inundation levels and durations during the wetland growing season and multiple year statistics. Farm pond daily water budgets are predicted for hydrologic design and reliability assessments of applications such as irrigation or livestock water supply, waste water lagoons and reservoirs. A previous hydrologic water budget model, SPAW, was expanded by enhancements and adding a comprehensive ponding routine to become SPAW-II, a single hydrologic computational package including operational and data screens, output tables and graphs, manuals and examples. The program theory, typical applications, data requirements and operational details are included. Program corroboration has been accomplished through a series of workshops and program tests.