Vermont Department of Environmental Conservation

Various Locations, Vermont

Great Hosmer Dam Evaluation & Design, Craftsbury. For the Dam Safety Section of the Department of Environmental Conservation (DEC) DuBois & King provided professional services to investigate and evaluate alternatives and prepare plans and specifications for repairs to the Great Hosmer Dam. The structure is a 6-ft-high, 23-ft-long masonry dam with a concrete cap, a central stoplog spillway, and a stone discharge channel downstream. The dam impounds the top 6 ft of Great Hosmer Lake, which has a surface area of 155 acres. Built in 1875, the Great Hosmer Dam was in poor condition, with concrete sections deteriorating, an inoperable stoplog/slide gate, scour at the left abutment, sinkholes, and a collapsing stone outlet channel. The dam is on a landlocked parcel of State land, so access to the site must be carefully coordinated with neighboring land owners. Services included:

Review of soil borings
Hydrologic and hydraulic analyses
Structural analysis
Rehabilitation alternatives
Construction plans and technical specifications
Construction cost estimates

Dog River Restoration and Drainage Design, Roxbury. Engineering and permitting services for the restoration of the Dog River and related drainage improvements to alleviate flooding problems in the Village of Roxbury. The river has been affected by historic changes including a railroad that parallels the river and cuts the valley in half, and historic dredging that resulted in a straight channel with little habitat value. Sediment deposition at the project site has blocked culverts under the railroad, causing regular flooding and an elevated water table that has impacted wells, septic systems, structures, and roads.

DuBois & King’s solution involved restoring 550 ft of the Dog River to provide more natural sinuosity and to move sediment deposition away from the existing drainage infrastructure. The solution included creating a new drainage swale, berm, and sediment basins to allow floodwaters to again flow under the railroad tracks to the Dog River. The D&K Water Resources Team prepared engineering drawings, including a site plan, channel profiles, river and swale cross sections, and details.

The project involved significant wetland disturbance and required clearance from both State and Federal regulators. DuBois & King conducted a site inspection to document functions and values of the wetland; conducted an alternatives analysis; coordinated with property owners and State and Federal regulators; and prepared applications for Conditional Use Determination (CUD) from the DEC Wetlands Program and Section 404 clearance from the US Army Corps of Engineers.