K&W Engineers and Consultants

Owner/Client

Lower Paxton Township Department of Public Works

Challenges

• Runoff from the Blue Mountain was discharging under Forest Hills Drive and flowing uncontrolled through forested lands that had been dedicated to the Township as park land.  Down grade of this township park land, several homes had been built along continental drive.
• The drainage area is very steeply sloped and severe erosion was occurring.
• Several temporary measured had been installed that were not capable of managing the runoff.
• The runoff discharges to a down grade collection and conveyance system which had limited capacity.
• The proposed system was to be installed by Township Public Works staff with limited resources.

Solutions

• K&W performed a thorough review of the drainage area, and discussed the history of flooding events with township staff and the residents.  Several pictures were obtained and reviewed to understand the runoff patterns and the significance of the flooding.
• K&W performed a hydrologic and hydraulic analysis of watershed and the downstream collection and conveyance system.
• K&W designed a multi-stage conveyance system with several drop structures which dissipated the energy of the runoff and delayed the peak discharge to the downstream conveyance system.
• Two different overflow systems were designed and incorporated to ensure safe conveyance of runoff in the event the rainfall and runoff significantly exceeded the design capacity.
• K&W prepared simple easy to understand plans and details for the Public Works staff to be able to install the system within the constraints of their manpower, machinery, materials, and money.