The NH Department of Transportation held its public hearing at AEMS on July 20. Project manager Jason Tremblay and Senior Project Engineer Ronald Kleim of NHDOT presented a preliminary design for project #40392 – replacement of the Rte 4 bridge between Fenvale and Plains roads.

The current bridge is described as a “through-girder” bridge, which is supported by its thick sheet-steel sides. This type of bridge is often associated with railroads, as it is strong and relatively simple to build, but narrow. Its span is 70 feet long, but it’s only 24 feet wide rail-to-rail, making it much too narrow to safely walk, fish or bicycle outside the traffic lanes. It was built in 1933 and received some major repairs in 2014, but is now number 13 on the state-wide list of “red-listed” bridges due to its decayed condition and sub-standard dimensions.

The DOT plan seeks to entirely replace the bridge with a 104 foot span, requiring a road closure lasting 28 days. Through traffic on the state highways will be re-routed onto Rte 127 in Salisbury, to go up Rte 3 and 3A and back into Andover on Rte 11, a 22-mile detour. (The Rte 11 bridge in East Andover near Dyer’s Crossing will also be under construction for some of this time, but without lengthy closures.)

The new bridge will be 32 feet wide from rail-to-rail, including two 5-foot shoulders. The bridge deck and its approaches will be about one foot higher above the river than the old bridge. There will be new guardrails and a drainage basin located in a portion of the current cornfield northeast of the bridge, to offset additional paved surface in the surrounding wetland areas.

The state’s engineers say they “can fix the bridge, but they can’t fix the flooding of the Blackwater”. The engineers will do further study to address the flooding we are experiencing every few years, most recently on July 12, when floodwaters reached the steel rocker bearings supporting the bridge span and flowed across the roadway, forcing a road closure. Raising the approaches one foot will improve this situation, and NHDOT will take measures to ensure floodwaters are unlikely to cause damage to the roadway.

Meli Dube of NHDOT’s Department of Environment identified the Blackwater as “essential habitat” for Atlantic salmon, and said that appropriate measures to minimize the project’s impact will be taken, but has found no other sensitive species will be affected. NHDOT recognizes that some farmland will be impacted, and Adam Smith of NHDOT’s Bureau of Right-of-Way is developing new farm road access from Rte 4 and compensation for lost acreage.

Andover resident Les Fenton, whose family owns land on both sides of the highway, expressed his sincere appreciation for all the hard work and consideration NHDOT has put into the project, protecting prime wetlands, minimizing the project’s impact on farmland and contemplating whether access to the river for fishing and canoeing might be provided.

Representative Louise Andrus expressed her concern that the long detour would add an hour, requiring “hard working people to get up half an hour earlier and get home half an hour later”, but she was “very happy it’s 100% federal funds”.

Thanks to the federal infrastructure bill passed recently, 100% of the bridge construction costs will be paid with federal dollars. Preliminary design and permitting is paid 80/20% by federal and state dollars, and no cost will be assessed to Andover residents.