Unnamed Wash

A 15-foot deep erosion rill had formed in an unnamed wash due to storm water flows, exposing one of four natural gas pipelines in the area. If left uncovered and unprotected, the pipeline risked further exposure and potential damage due to continued pipeline erosion.

In order to restore cover to the exposed pipeline and stabilize the soils, Submar constructed a mechanically stabilized earth (MSE) wall with a drop structure. The project area was excavated and graded as necessary; the crew began building the MSE wall using grading stakes, welded wire baskets, soil reinforcements, Miramesh, gabion stones, and Miragrid. Within the sequence of building the MSE wall, a drop structure with a vortex diffuser was constructed with a 24-inch diameter drainage pipe within the left-descending bank to convey sheet flow from the high bank to the unnamed wash. A 12-foot by 12-foot concrete pad was installed around the pipe inlet. A 3-foot deep subgrade rock grade control was installed at the bottom of the culvert outlet to prevent storm flow from eroding the bed of the channel.