Gateway Stormwater Ponds Tunnel

Completed in 2015 by Mole Constructors, the Gateway Stormwater Ponds Tunnel project serves to alleviate stormwater flooding in the vicinity of Interstate Highway 10 (IH10) during and after heavy rain events. An existing stormwater pond was expanded, and a new stormwater pond was built as a separate contract. The tunnel acts as an equalizer between the two ponds to increase efficiency. This project was issued as a “design/build” in order to complete this project before the “rainy season”. Southland joined forces with Brierley Associates, who has proven to be a valuable partner on many previous projects. Brierley completed the 30% drawings, specifications and geotechnical reports which allowed Southland to begin construction. Brierley and Southland worked together as a team in both the pre-construction and construction phases of the project to avoid costly mistakes which could delay completion of the 580 linear feet of 96-inch liner-plate tunnel with 72-inch RCP carrier pipe. Crossing beneath IH10 required constant ground monitoring and grouting of voids behind the liner plate. The annular space between the carrier pipe and liner plate was also grouted.