Formed 18,000 years ago, it has its source in the prairie surrounding Katy, Fort Bend County, and flows approximately 53 miles (85 km) east through the Houston Ship Channel into Galveston Bay and the Gulf of Mexico.

Additionally, Buffalo Bayou is considered a tidal river downstream of a point 440 yards (400 m) west of the Shepherd Drive bridge in west-central Houston.

[1] The upper watershed of Buffalo Bayou is impounded by the Addicks and Barker reservoirs, which comprise a major flood control system for the region.

The reservoir system plays a crucial role in delaying and attenuating the peak outflow of the river during large rainfall events.

[8][12][13] Harrisburg served as the region's major trade center until the 1870s, when a large fire destroyed its railroad facilities, which were subsequently rebuilt in Houston.

[16] Combined, these reservoirs provide 410,000 acre-feet (510 million cubic meters) of runoff storage, which has largely prevented downstream flood events.

[18] The length of bayou between these two channelized sections, which largely runs through the Memorial Villages, has remained in its natural, meandering state.

The city has invested over $3 billion into new sewers, pumping stations, and sewage treatment plants across the metropolitan area, which has significantly improved water quality in the region.

In 1986, the Buffalo Bayou Partnership, a nonprofit organization, was founded to leverage public and private financing towards renovating and expanding park space along the river.

[20] The project goals include the rehabilitation of formerly industrial land, habitat restoration, canoeing and kayaking facilities, hike-and-bike trails, cultural programming, flood control management, and mixed-use urban development.

In 2015, the Partnership completed Buffalo Bayou Park immediately to the west of the Promenade, adding another 160 acres (65 hectares) of renovated parkland along a 2.3-mile (3.7 km) stretch.

In 2006 the Houston Cistern, managed by the Buffalo Bayou Partnership, started offering historical tours and immersive art exhibits.

[21][22][23] In August 2017, extensive rainfall from Hurricane Harvey brought the bayou to record high levels, shattering previous flood crests by several feet.

Lying over relatively impervious soils and very flat topography, the bayou has extensive natural floodplains, as do most Gulf coastal rivers and streams.

[29] The two most prominent flood control features in the Buffalo Bayou watershed are the Addicks and Barker reservoirs in western Harris County, which provide a combined 26,000 acres (11,000 hectares) of open land for runoff storage.

[32][33] Buffalo Bayou is legally navigable by paddle craft from its source in Katy to the western end of the Ship Channel upstream of Wayside Drive.

The section from Beltway 8 to Briarbend Park is generally kept clear of blockages by the Harris County Flood Control District; however, there are several gravel bar hazards to negotiate during normal water flows.

[19] Today, the bayou still faces significant environmental challenges, including elevated levels of indicator bacteria, low oxygen saturation, and heavy nutrient pollution.