The need for storm water attenuation becomes increasingly important as development continues to urbanize and expand housing, roadways, and other impervious drainage areas. Combine that with the expensive costs associated with land use, it is easy to see why owners are relying more on the use of underground storm water management solutions. Dedicated storm water attenuation, such as oversized sections of storm sewer lines within a storm drain system, can hold and detain peak flows during rain events and allow full use of the land surface above.
Improvements to Stringtown Road in Montgomery County, MD included two such underground storm water attenuation systems as part of the storm drain plan. Charles P. Johnson & Associates, Inc. designed each of the two systems as 96” diameter reinforced concrete pipe meeting ASTM C361 class D25, including precast plugged ends, pipe openings, and manhole-tee fittings.
CP&P’s Salem, VA facility produced the 96” pipe, fittings, and plugged end sections for the two systems, the North system consisting of 13 pipe sections (103.17’) and the South system consisting of 9 pipe sections (71.0’) plus risers to grade. Pipe and fittings were delivered with embedded lifting devices, allowing Kinsley Construction to maneuver and install the heavy sections into place on the jobsite.