The San Jacinto Galveston Bay watershed is located at the southeastern edge of Harris County. The watershed primarily drains the area that includes La Porte, Morgans Point and portions of Pasadena. However, Galveston Bay is the ultimate outfall for all drainage in Harris County. The Galveston Bay watershed covers about 20 square miles and includes two primary streams: Little Cedar Bayou and Pine Gully. There are about 24 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 San Jacinto Galveston Bay watershed is 14,952.
Structural flooding has occurred in low-lying areas adjacent to the water bodies. However, water surface elevations in Galveston Bay are not affected by the flow from the bayou system. Water Surface elevations in Galveston Bay are tidally influenced and can be affected by storm surge.