Two dams in a park owned by a community association were damaged by storm flows. The lower dam was breached and required design alternatives for its removal; the upper dam had to be evaluated for repairs. D&K reviewed the structural elements of both dams, the retaining wall, and the stream character upstream and downstream. Our…
Framed by a public park and a residential area and carrying a city street, Robin Hood Dam was reclassified by the State of New Hampshire as a high-hazard dam, and its spillway did not have the capacity to meet New Hampshire Dam Safety requirements. The City of Keene engaged D&K to evaluate the dam, develop…
The Upper Wilson Pond Dam is a small, high-hazard, earth embankment dam impounding a recreation pond. Recently found to be in poor condition, the dam is owned by the Town of Swanzey, and the pond is bounded by homes and properties located within the City of Keene. D&K’s project team completed a study that evaluated…
Storm flows from Jewell Brook in Ludlow are controlled by flood control dams (numbered 1, 2, 3, and 5) located in a rural, hilly, largely forested area. Previous evaluations of this system indicated that Site 1 had the potential for overtopping and the spillway design hydrograph would exceed allowable stresses at three of the system’s…
Curtis Pond, the dam, and its site serve as a beloved cultural hub and source of identity to Calais and the Maple Corner community. The dam underwent excessive seepage, movement of the stone wall, and piping of the earth/sand backfill through voids in the wall. The project had long-term enthusiastic partners, including the Curtis Pond…
The Allen Site Dam is a 1,520-ft-long by 21-ft-high earthen NRCS flood-control dam in a suburban context. The Town of Walpole wanted the dam maintained to provide flood mitigation for an increased level of downstream property development. D&K provided survey, inspection, breach analysis, and a range of other services to evaluate the current state of…
The Norwich Reservoir Dam was a run-of-the-river, cyclopean concrete gravity dam located on the Charles Brown Brook. The dam impounded a reservoir which became silted in, and the dam served no useful function. The dam caused significant negative impacts to the brook and to downstream reaches. The dam blocked fish passage and caused downstream sediment…
The Harrison Lake National Fish Hatchery required rehabilitation of several aging kettles that controlled water level in ponds, movement of water between ponds, and pond draining. D&K completed a topographic survey of the site to identify the location and as-built elevations of each kettle and valve replacement. Our structural engineers reviewed the original kettle design…
Sweet Pond Dam is a 20-ft-high by 77-ft-long circa-1928 dam that impounds an 18-acre pond with a contributing drainage area of approximately 1 square mile. The dam sustained uncontrolled and excessive seepage through highly fractured and weathered bedrock and posed a barrier to AOP. D&K provided planning, evaluation, alternatives analysis, preliminary and final design, permitting…