Rolling in the Deep Groundbreaking Advances Made with EPBM Tunnel Constructed Below Sea Level Christine H. Kirby, P.E., ENV SP | Lockwood, Andrews and Newnam Inc. 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 22 OCTOBER 2023 | UndergroundInfrastructure.com (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 percent of total water use in 1976. Inhttp://www.UndergroundInfrastructure.com