Hoyle Tanner prepared a hydrologic and hydraulic study for the replacement of a structurally deficient corrugated metal pipe (CMP) and reinforced concrete pipe.
The existing crossing is comprised of two adjacent culverts. The west culvert is a 4’ diameter reinforced concrete pipe and the east culvert is a 3’ diameter CMP. Due to its deteriorated condition and history of flooding in this area the Town of Derry is investigating replacement options for these culverts.
Hoyle Tanner performed hydrologic and hydraulic analysis and evaluated the existing opening of the culvert and recommended a new culvert type and opening that passes the 50-year flood event with a minimum of 1′ of freeboard per New Hampshire Department of Transportation (NHDOT) requirements. The recommended structure type will be 30’ in span. The project was fully funded through Town funds.
SERVICES
Hydraulic Analysis
Study
Final Design
Bid Process Administration
Construction Administration
From the blog
Learn about ongoing projects and the innovative processes we employ for our clients.
For decades, airports have largely planned their fueling facilities around two familiar products: 100-octane low-lead aviation gasoline (100LL) for piston-engine aircraft and Jet A for turbine-powered aircraft. That landscape...
Christian Boisvert, PE, Hydraulic Engineer & Amateur Rugby Player What drew you to Hoyle Tanner? I really liked the size of the firm and the local office in Burlington,...
Infrastructure improvements continue at Clearbrook Condos, a 240-unit condominium community in Lincoln, NH, located across the river from Loon Mountain Ski Resort. What started as a conversation about aging...
We’re recognizing our November employee anniversaries and celebrating the 19 combined years these employees have spent growing, contributing, and making an impact at Hoyle Tanner.
In Fair Haven, Vermont, some sewer lines have served the community for nearly 120 years. Like many long-standing infrastructure systems, the collection system experiences a range of challenges. Aging...
Whether we're walking the dog, heading to work, taking our children to the bus stop, or enjoying New England's fall foliage, most of us are pedestrians at some point...
Demand for aircraft hangars is outpacing availability at many airports. According to the Aircraft Owners and Pilots Association (AOPA), 71 percent of airports across the country have reported a...
Stormwater is one thing people rarely think about until there is a problem. A flooded roadway, a washed-out culvert, standing water in a neighborhood, erosion along a streambank, or...
The Worcester-Elmore Route 12 Bundled Bridges Project has received the 2026 Northeastern Transportation and Wildlife Conference (NETWC) Innovation – Transformation Award. The recognition reflects an approach that treated bridge...
