The Buffalo Bayou watershed is primarily located in west-central Harris County with a small portion crossing into Fort Bend County. Rainfall within the 102 square miles of the Buffalo Bayou watershed drains to the watershed’s primary waterway, Buffalo Bayou (HCFCD Unit W100-00-00). Buffalo Bayou travels through heavily wooded residential areas and much of the bayou remains in a natural state. Near downtown Houston, White Oak Bayou (HCFCD Unit E100-00-00) flows into Buffalo Bayou.
Just east of downtown Houston near the Turning Basin, Buffalo Bayou becomes the Houston Ship Channel. There are 106 miles of open waterways in the Buffalo Bayou watershed, including Buffalo Bayou and its major tributaries, such as Rummel Creek (HCFCD Unit W156-00-00), Soldiers Creek (HCFCD Unit W141-00-00), Spring Branch (HCFCD Unit W140-00-00), and Turkey Creek (HCFCD Unit W167-00-00). Based on the 2010 U.S. Census, the estimated population of the Harris County portion of the Buffalo Bayou watershed is 444,602.