Between a Rock and Hard Place: Rehabilitating a Storm System Around a Difficult Site

Amanda Johnson, Project Engineer I, Timmons Group

David Duncan, Project Manager, Timmons Group

Edward Heide, Operations Manager, City of Suffolk Public WOrks Roadway Maintenance

A storm system in the city of Suffolk, VA requires a structure replacement and pipe rehabilitation. Sounds like a typical day in the life of a stormwater engineer, right? However, there are a few extenuating circumstances that make this project unique.

The upstream end of the storm pipe in need of rehabilitation can be found between an active railroad and a hole that drops nearly 20’ elevation over 35’, making it one of the steepest sites in Hampton Roads. The storm pipe runs from the basin, under the active railroad, and into the structure just south of a roadway. Our grated inlet structure lies in a drainage ditch that is approximately 14’ x 6’ wide, 18’ deep, and at risk of failure. A portion of the pipe has pushed into the structure, cracking the structure’s southern wall in on itself while cracks were forming throughout the rest of the structure. Our site conditions leave us with several obstacles to work around including few bypass pumping options and limited heavy equipment access.

This presentation will discuss the distinctive characteristics of our project site, what avenues were explored and selected to rehabilitate the system, the construction sequence established, and lessons learned from the design process.

Author Bio

Amanda Johnson is a Project Engineer I for Timmons Group who recently graduated from Old Dominion University with her Bachelors Degree in Civil and Environmental Engineering. She has worked on a variety of Stormwater Projects with Timmons Group including retention ponds, channel restoration, pipe rehabilitation and stormwater system optimization.