This document is the case study for the Sheppard Air Force Base, Wichita Falls, TX. French drains to avoid ponding between runways discussed.

Sheppard Air Force Base has eliminated ponding between two runways, caused by the failure of corrugated metal pipe, by building a large French drain. The French drain consists of three runs of 60” (1500 mm) diameter HP Storm pipe that is perforated with ⅜” (9 mm) holes around the pipe.

HP Storm was chosen because of the strength of polypropylene pipe. The strength was needed because of the expansive clays, bentonite clays, that shrink and swell putting pressure on the pipe.

In addition, HP Storm was able to be installed quickly as the contractor put in roughly 150’ (45 m) of pipe per day. Branch runs of 18” (450 mm) HP Storm were utilized for the surface water running near the mains. The smaller diameter pipe was connected to the mains using Inserta Tee lateral connections. Inserta Tees were also used to connect the mains to concrete structures, which were specified for clean out purposes.

The installation was done in November 2017 using 580’ (177 m) of 18” (450 mm) of HP Storm pipe, 19,600’ (5974 m) of 60” (1500 mm) of HP Storm pipe, Inserta Tee.

Photographs of the project are included.