Blackstone provides on-call engineering services for Magellan Pipeline Company. We help Magellan evaluate and correct underground pipeline exposures and at-risk foundations for cable-suspended overhead pipelines due to erosion at stream crossings. Blackstone has worked on over 100 of these types of projects for Magellan over the past six years. This location in Atchison County, Kansas included one underground pipeline and one cable-suspended overhead pipeline crossing Deer Creek. The underground line was exposed in the stream bed and one of the support towers for the overhead line was in jeopardy of being undermined due to bank erosion.
The streambank stabilization design included the construction of modular concrete block walls along both banks and rebuilding the banks behind the walls to protect the integrity of the overhead line support towers. The newly shaped banks were protected with permanent turf reinforcement mat to maintain bank structure during vegetation growth. A shot-rock riffle was also placed on the channel bottom to protect the underground line. Upstream and downstream rock cross-vanes were installed in the channel for grade control and to direct the flowline to the center of the channel and away from the banks at the pipeline crossing. This correction was much less expensive than the alternative of horizontal drilling the pipelines deeper under the creek.