DTC was retained by the Town of North Haven to perform a drainage and hydraulic analysis of known flooding areas in the vicinity of Todd Drive and Todd Drive South. More than 60 residential properties are currently affected by flooding, spanning across three distinct study areas.
DTC’s study evaluated alternate improvement options intended to reduce the effects of flooding in the study area. Proposed improvements included additional culvert capacity at several existing crossing locations under the Merritt Parkway, as well as localized flood protection measures at several residential properties. The new Wilbur Cross Parkway work was designed for installation via Pipe Jacking methods. Three 48” culvert barrels were designed to alleviate flooding along Pine Brook, and an additional 48” culvert was designed for a smaller unnamed brook 1,500 feet to the north.
Estimated costs of the proposed improvements are in excess of $2.0 million.
In order to construct the proposed improvements, it was necessary to disturb some inland wetland areas adjacent to the streams in our project area. Design of remediation measures to compensate for these disturbances was an important part of obtaining the necessary approvals to do the proposed work. DTC worked closely with CT DEEP, and U.S. Army Corps of Engineers to include new wetland and upland plantings within and adjacent to the proposed areas of disturbance. These plantings included numerous planting “zones” developed to allow for a diverse mix of plants with different flood tolerance to be included in the overall remediation area. These zones will improve plant diversity, and establish a better overall ecosystem at this location.
To address the existing channel bank erosion issues, DTC developed designs incorporating a mix of structured and vegetative solutions. Designs were reflective of differing velocities at different depths and locations within the channel.