(UI) — In response to a mandate issued by the Harris-Galveston Subsidence District (HGSD) to increase usage of surface water and decrease groundwater use, Houston Public Works created the Surface Water Transmission Program (SWTP).

To aid in preventing future ground subsidence and alleviate infrastructure damage and flooding, the SWTP Program goals are to increase surface water usage, decommission and/or minimize the use of groundwater pump stations, increase water system pressures and address other large-diameter water line issues. 

According to HGSD, groundwater use in the Houston region made up about 60% of total water use in 1976. In 2020, the percentage has dropped to 21%, and a 9% decrease in ground water pumping from 2019.

The SWTP 72-inch Water Line from Emancipation to Tuam is the first segment in a series of four that will serve as a refill line to the Southwest Pump Station (SWPS). After rupture of a 42-inch surface water refill line in 2004, the city evaluated vulnerability of supply to its three major repump stations. 

SWPS is the heart of the system, and shutdown of the more than 50-year-old, 66-inch, pre-stressed concrete cylinder pipe (PCCP) – the current primary source – would impact the system’s ability to supply the western half of the city. A new 72-inch water line was initially identified as a secondary refill line but would become the primary supply line for SWPS and provide an opportunity to assess and rehabilitate the existing 66-inch water line.