Harrisburg, Houston in the context of "Downtown Houston"

Harris County is a county located in the U.S. state of Texas. As of the 2020 census, the population was 4,731,145, and was estimated to be 5,009,302 in 2024, making it the most populous county in Texas and the third-most populous county in the United States. Its county seat is Houston, the most populous city in Texas and the fourth-most populous city in the United States. The county was founded on December 22, 1836 and organized on March 10, 1837. It is named for John Richardson Harris, who founded the town of Harrisburg on Buffalo Bayou in 1826. It contains over 16% of the state's population. Harris County is included in the nine-county Houston–The Woodlands–Sugar Land metropolitan statistical area, which is the fifth-most populous metropolitan area in the United States.

Brays Bayou is a slow-moving river in Harris County, Texas. A major tributary of Buffalo Bayou, the Brays flows for 31 miles (50 km) from the western edge of the county, south of Barker Reservoir along the border with Fort Bend County, east to its convergence with the Buffalo at Harrisburg. Nearly all of the river is located within the city of Houston; it is a defining geographic feature of many neighborhoods and districts, including Meyerland, Braeswood Place, the Texas Medical Center, and Riverside Terrace.

As a result of its central route through Harris County, the Brays Bayou watershed is heavily urbanized. Over 700,000 people reside within its 129-square-mile (330 km) drainage area, which contains 124 miles (200 km) of open-channel waterway, mostly from artificial drainage channels. This high level of development, combined with a relative lack of flood control infrastructure, means Brays Bayou is extremely prone to flash flooding events.