Published DateWATERVILLE VALLEY — CMA Engineers recently completed work on three Waterville Valley bridges that span the Mad River, one of which was washed away during Tropical Storm Irene.
The completion of the bridges allows people using Waterville Valley's miles of recreational trails to more easily cross the rapid waterway, while also making the roads in Waterville Valley safer for pedestrians.
When the flood waters of Tropical Storm Irene surged down the Mad River in 2011, a pedestrian bridge along the Inner Mad River Recreational Trail was lifted off its bearings and floated approximately 1,200 feet downstream. The original 100-foot span, which was built in the early 1980s, was an important river crossing along Waterville Valley's cross-country ski network.
As part of a 2012 FEMA-funded bridge replacement project, CMA Engineers worked with the town to remove the original bridge from the Mad River. After examining the bridge for possible reuse, CMA Engineers determined the original bridge could not safely be repurposed. CMA Engineers then designed and constructed a new 110-foot single span truss bridge that connects the Village of Waterville Valley to more than 60 kilometers of recreation trails in the White Mountain National Forrest. CMA Engineers completed the project in time for the 2012 ski season.
CMA Engineers also built a timber pedestrian walkway along the downstream side of the West Branch Road Bridge spanning the Mad River. The 65-foot bridge was widened with a timber walkway to provide safe pedestrian access across the river year-round.
But Tropical Storm Irene would leave a mark on this project as well. While under construction, the river surge washed out the approach to the westerly walkway of the West Branch Road bridge. When CMA Engineers went in to make the repairs, it also provided a scour countermeasure design and deck repair designs so that the bridge could be quickly repaired while the road approaching the bridge was stabilized. These designs reduced the time the road and bridge was closed for repairs.he bridge expansion is now connected to a new 140-foot causeway along West Branch Road linking it to the residential area adjacent to the Waterville Valley Academy. The two new walkways make access to the trail system that converges at West Branch Road and the Mad River safer for pedestrians.
Waterville Valley is a premier four-season mountain resort, offering exceptional recreational connectivity for hiking, biking, and cross country skiing. These bridge repairs, which were started in 2009, were part of a multi-year engineering project to upgrade some of Waterville Valley's bridges across the Mad River.