Project: Peachwood I SWMP Retrofit–
Client: Montgomery County Department of Public Works,Capital DevelopmentDivision
Location: Montgomery County, MD
Work included: removal and disposal of CMP riser and barrel; cast inplace structures; installation of precast riser with RCP barrel, cradle and collar; clay core with dam embankment; sediment and erosion control; stabilization of affected area; and quality control and assurance.
The scope work of the modifications to the Peachwood SWMP included the replacement of the existing CMP barrel and riser with a new 42” RCP spillway with a precast control riser structure and weir trash racks. In order to prevent erosion and allow solids to settle out of storm runoff a 24” high density, corrugated PVC sheeting wall was installed. A concrete cradle and collar were installed on the barrel through the embankment. A clay core was placed in coordination with the collar in the dam, as well. The emergency spillway was modified with a gabion weir in order to permanently stabilize the area. Also, an extended detention plate was installed on the headwall as well as low flow trash racks. Existing geometric configurations were incorporated into the design to comply with MDE dam safetystandards.
Access tothe Peachwood SWMP was maintained throughout construction by setting up lane closures during deliveries and when construction activities encroached on Good Hope Road. Placement of the precast riser required the use of a crane setupin the footprint of the pond to avoid the overhead utilities that run the length of the dam embankment. Lane closures were in accordance with approved plans and were monitored by Montgomery County Department of Roads.