To widen and realign I-84 through Waterbury, a river, a brook, and a stream will all have to be realigned or relocated. These watercourses and waterbodies, are identified as receiving waters for this project, and located along this section of the highway include the Mad River, Beaver Pond Brook, and several named and unnamed tributaries. Below are the proposed watercourse realignments.

• Realignment and stabilization of the Mad River channel from south of the existing EB 24 Off-Ramp to Harpers Ferry Road to north of Plank Road to accommodate roadway widening and realignments and new bridge crossings.
• Realignment of Beaver Pond Brook channel in the Scott Road area will allow for a revised alignment of the WB 25 Off-Ramp, which is necessary to realize traffic safety and operational improvements at this interchange.
• Relocation of East Mountain Brook at its confluence with Beaver Pond Brook to accommodate the I-84 relocation and widening and Reidville Drive relocation.
• Re-establishment of a Perennial Stream in the Mountain Village Road area.
• Extensive In-stream habitat enhancements associated with the watercourse relocations.

The proposed project impacts approximately 2347 m (7,700 feet) of watercourses and 0.5 hectare (1.3 acres) of wetlands. The mitigation for the watercourse impacts are accomplished within the project limits through eliminating obstructions to fish migration and extensive in-stream habitat enhancements. Based on the mitigation strategy and mitigation ratios accepted by the US ACOE, the project will need to provide approximately 1.2 hectares (3 acres) of restored or newly created wetlands. CTDOT is in the process of investigating wetland creation sites.

The design of these relocations has incorporated habitat enhancement measures intended to improve habitat and fish passage potential, integrated with channel structural grade stabilization elements.