1999 Chevy K3500 Wiring Diagram The Seasonal Water Yield (SWY) model estimates the amount of water produced by a watershed, arriving in streams over the course of a year. The primary outputs of the model are quickflow, local recharge, and baseflow. Quickflow represents the amount of precipitation that runs off of the land directly, during and soon after a rain event, and local recharge represents the amount of rainfall that infiltrates into soil, minus what is evaporated or used by vegetation. Baseflow is the amount of precipitation that enters streams more gradually through sub-surface flow, including during the dry season. The model is based on inputs of topography (DEM), soils, land cover and management, rainfall, and vegetation water demand.