Delivery of Source Loads
Once the daily outputs from each source cell and the flow distances from the source cell to stream are determined, the flow and constituents are routed to the nearest stream within the Basin Land Area and Stream Routing sub-model (BLASRoute). BLASRoute routes the flows and loads based on the distance grids previously calculated and delivers water and constituents to the streams based on assumed flow velocities and unit hydrographs for both surface and ground water flows. Constituents contained in the runoff are attenuated based on features encountered en-route such as wetlands and depressions. See Technical Manual for additional details of this routing process.

Groundwater withdrawal wells can be placed to extract the water en-route to a reach, representing various physical processes such as irrigation demands.
