The Sims Bayou watershed is located in southern Harris County. Most of the watershed is within the City of Houston. However, the upper reach of the watershed drains the City of Missouri City and the lower reach of the watershed drains the cities of South Houston and Pasadena. The Sims Bayou watershed covers about 94 square miles and includes two primary streams: Sims Bayou and Berry Bayou. There are about 121 miles of open streams within the watershed, including the primary streams and tributary channels. Based on the 2010 U.S. Census, the estimated population of the Harris County portion of the Sims Bayou watershed is 284,727.
Structural flooding has occurred numerous times along Sims Bayou and its tributaries. The majority of the structures that are flood prone were built prior to the existence of detailed floodplain maps and prior to floodplain management regulations.