- Bathymetric Survey and Sediment Sampling Field Services Quantified and Characterized Sediments
- Hydraulic Dredging Program Designed to Minimize Turbidity Impacts Downstream
- Local, State & Federal Environmental Permitting
- Construction Plans, Specifications, Bid Phase and Construction Phase Services
- Landscape Restoration/ Improvements for Pond Margins
- Development and Permitting of Comprehensive Water Resources Adaptive Management Plan for the Campus
Challenge
The Mill River watershed leading to Paradise Pond comprises 54 square miles of steep, mostly undeveloped and wooded terrain in the foothills of the Berkshire Mountains. Frequent flash flooding on this high-energy river causes mobilization of naturally-generated sediments, and some degree of sediment removal must be conducted every seven to 10 years to maintain the historic open water area of Paradise Pond, located on the campus of Smith College. GZA was initially engaged by Smith College in 2004 to address immediate concerns and retained in 2015 to address long-term solutions and provide more comprehensive management.
Solution
GZA provided design, permitting, and construction phase services to Smith College including hydraulic dredging of Paradise Pond, which is continuously subject to sedimentation and relatively rapid re-accumulation of sediments as an impoundment of the Mill River. Past dredging efforts had involved draining the pond and using excavation machinery, which caused significant sediment deposition downstream of the pond due to the difficulty of controlling mobilization of sediment once the pond drain was re-opened. This conventional dredging method negatively impacted a habitat area to several rare and endangered species downstream of the pond. Therefore, GZA designed a hydraulic dredging program that minimized impacts of turbidity to endangered species downstream by requiring a mechanical sediment dewatering program sited upland to the pond. The selected contractor used geotubes to dewater the sediments, excavating and hauling the sediment from the geotubes to an offsite reuse location. During a six-month dredging operation, 12,000 CY of the 44,000 CY of accumulated sediments were removed from Paradise Pond.
To address continuing and long-term management concerns, GZA has worked with the college since 2015 to develop a comprehensive Water Resources Adaptive Management Plan (WRAMP) for all campus water resources, including Paradise Pond, the Mill River, and Lyman Pond. Routine portions of the WRAMP achieved full permits in 2018.
Benefit
With GZA’s comprehensive pond management services, Smith College is a better steward of Paradise Pond and the entire watershed, and the college achieves its environmental, aesthetic, and recreational goals for the campus water body.