Westtown Lake Dam Rehabilitation and Dredging

Princeton Hydro worked with the Westtown School on dam safety compliance and lake restoration for 10 years and was the Engineer-of-Record for the restoration of the dam and lake dredging. This long-term client initially contracted Princeton Hydro to complete dam inspections and assess the lake in terms of its environmental health and the need for dredging. As part of the rehabilitation of the dam, Princeton Hydro surveyed and designed the dredging of 68,000 cubic yards of sediment, the rehabilitation of the lake’s sedimentation forebay and spillway, and the enlargement of a culvert on Westtown Road, immediately downstream of the dam. The culvert replacement was required due to the closure of 2 secondary outlets on the dam and corresponding culverts below Westtown Road.

Our firm has also completed periodic visual inspections, dam breach and inundation analysis, the preparation of an Emergency Action Plan (EAP), and the Operations and Maintenance Manual. For rehabilitation, Princeton Hydro designed the dam to be able to pass the 100-year flood event via a completely new drop spillway and outfall barrel, and the construction of an auxiliary/emergency cast-in-place stepped spillway.

This project required a number of different permits, including a Chester County soil erosion and sediment control plan approval, a Dam Safety construction permit, a PADEP General Permit 11 for the road crossing, and a USACE Individual Permit in compliance with the Federal Clean Water Act. Princeton Hydro also successfully navigated considerations for two species of concern; potential bog turtle (federal and state listed) habitat and known red-belly turtle (state listed) populations.Following design and permitting, Princeton Hydro provided construction documentation and administration, including the review of shop drawings, monitoring soil compaction, inspecting concrete pours, and collecting concrete test cylinders for break tests, completing monthly progress reports, reviewing payment requests and change orders, and attended bi-weekly project meetings with the client.