The Town of Bow needed to replace a 20-ft, rigid-frame culvert with inadequate scour protection, foundations, and geometry. The roadway serves heavy truck traffic and intersects with NH 3A, a state highway frequently used to bypass a tolled section of I-93 near the Interstate I-89 intersection with I-93. D&K designed a replacement structure to address…
The Vermont Agency of Transportation had to replace a buried water conveyance structure that was (hydraulically) undersized and causing the rail and roadway embankments to act as a dam during moderate and large storm events. Located 70 feet below grade in some places, the existing system of metal pipes and concrete structures was in poor…
Bull Run Road, a two-lane residential road abutting a perennial stream, underwent a slope failure during a large storm event. Heavy stream flows scoured the toe of the roadway embankment causing the roadway slope to fail and restrict capacity to one lane. The Town of Roxbury secured FEMA funds to evaluate the situation and implement…
The Vergennes 9B Hydroelectric facility is a historic hydroelectric plant on the Otter Creek centrally located in downtown Vergennes. Its penstocks were nearing the end of their service lives, and the facility was in need of reconfiguration and operational improvements. D&K worked with the client to design new penstocks and reconfigure the powerhouse to significantly…
Located downstream of a large flood control dam, the EHC hydroelectric facility includes turbines at two locations along a one-mile-long intake channel and produces approximately 1.26 MW. The owner needed to replace and upgrade various components of the intake, including replacing the headgate lifting frame, replacing the rack-raker system, replacing the existing timber site/retaining walls…
To address conditions posed by structural concrete sections nearing the end of their service life, the owner needed to rehabilitate the intake structure at the lower Middlebury hydroelectric project. The D&K team designed improvements, including a new reinforced concrete headwall structure to utilize portions of the existing headwall while allowing for equipment clearance requirements. D&K…
Along Otter Creek, a 160-ft-long, 20-ft-high slide occurred on the Gooseneck Bend Road embankment, disrupting the roadway’s stability. The Town of Weybridge secured FEMA funding and engaged D&K to evaluate the failure and design long-term improvements that armored the embankment along the roadway using stone armoring and plantings, stabilizing the immediately adjacent gravel road.
In response to repeated storm damage to this 1,900-ft-long, circa 1960s Army Corps granite block protection levee, the Town of Lincoln needed to repair the levee to maintain an acceptable level of service. DuBois & King evaluated the structural, hydrologic and hydraulic, civil, and structural conditions and requirements of this site along the Pemigewasset River….
Approximately 400 LF of the Town Highway 35 (Gilman Road) embankment along the White River failed as a result of flooding following a severe storm. The vertical height of the failed riverbank is approximately 80 ft. The road embankment was eroded, and the resulting slope was unstable and vulnerable to damage. On behalf of the…