The banks of the Anacostia River in Maryland began to erode, just like countless river banks across countless streams, but this bank migration exposed a pipeline that could become a failure and a danger. Lateral migration can impact an entire pipeline and cause serious structural damage to the integrity of the system.
In this case, rock was placed to stabilize the river bank, but the rock did not correct the pipeline erosion issue for long. A particularly dangerous situation can occur if a pipeline is left exposed due to erosion. If left uncovered and unprotected, this 22-inch diameter natural gas pipeline site risked potential damage.
Submar approached the problem on several fronts. This was a multi-pronged issue and required several steps to ensure the safety of the pipeline:
- Our Submar construction crew sandblasted and recoated the pipeline to restore its integrity.
- The site was graded to create uniform contours.
- The Submar mat system, a system of articulating concrete revetment mattresses, was then installed. This system allows natural vegetation to grow, retains the grade to ensure streambank stabilization, and prevents future streambed degradation.
- Next, material from the streambed was placed on top of the mat system in the form of constructed riffles to dissipate stream velocity.
- The crew then placed stones on the toe of the banks above the thalweg, the lowest point along a streambed, and installed a rock sill downstream of the mat system to aid in preventing further streambed degradation.
- Once the final grading was complete, the crew installed erosion control blanket on the banks and placed seed and straw to prevent erosion and encourage vegetative growth.
To learn more about how we offer solutions on lateral migration, see our projects page.