GIS and Remote Sensing in Hydrology, Water Resources and Environment (Proceedings of ICGRHWE held at the Three Gorges Dam, China, September 2003). IAHS Publ. 289, 2004, 33-40

Abstract Small earthen dams referred to as flood retarding structures (FRSs) represent one of the most effective methods for reducing damage caused by flooding from agricultural land. The impact of these structures on streamflow regime under dry, average, and wet climatic conditions was investigated in this study. The setting for the study is the Little Washita River Experimental Watershed (LWREW) in southwestern Oklahoma, USA that contains 42 FRSs. The Soil and Water Assessment Tool (SWAT) is used to evaluate changes in streamflow characteristics as a result of the FRSs for five subwatersheds on the LWREW ranging in size from 33 to 596 km2. The most noticeable impact of the FRSs is the reduction of annual maximum daily discharges on the day of a rainstorm, with decreases among the subwatersheds ranging from 9 to 31%, 20 to 34%, and 22 to 43%, for the dry, average and wet conditions, respectively.

Key words flood retarding structures; streamflow; SWAT; watershed simulation