In 2003, the West Authority reached an agreement with the City of Houston to partner in a water supply contract; the West Authority purchased the right to a certain amount of capacity in the city’s East Water Purification Plant and the right to purchase future capacity in the City of Houston’s Northeast Water Purification Plant, as well as space in some of the transmission pipelines that transport water from the plants to west Harris County.

The surface water used in the West Authority comes from the City of Houston, which owns the majority of surface water in the Houston region. The City of Houston owns three reservoirs – Lake Houston in north Harris County, Lake Conroe in Montgomery County and Lake Livingston in Trinity County. Currently, the City of Houston treats water from Lake Houston and Lake Livingston and moves it through large transmission lines to water customers throughout the region, including the West Authority.