Seepage Mitigation
Gorham Canal Embankment
Gorham Hydropower Station
Berlin, NH
The Gorham canal together with its headgates controls the flow of Androscoggin River water to the Gorham Hydropower Station. Provided design and construction quality assurance (CQA) oversight services for the mitigation of a portion of the Gorham canal embankment through which seepage had been observed by Brookfield personnel upon watering-up the head pond after an extended period during which the canal was dewatered. New Hampshire Department of Environmental Services and FERC have regulatory authority of the facility.
Collaborative efforts with Brookfield, regulators, and the selected contractor allowed the project to be designed, permitted, and constructed in less than one month.
SchonewaldEA completed an initial site visit with the owner. Subsequent collaborative work included development of a mitigation work plan, design of a graded filter system, and preparation of a design package for construction that were submitted for regulatory review and approval within three days of the site visit; approvals were received that same day. SchonewaldEA provided on-site construction oversight and prepared the record report.
SchonewaldEA retained by Brookfield Renewable Energy Group
Dam Crest Widening & Vehicle Turnaround
Wyman Dam
Kennebec River, Moscow, ME
Wyman Dam is located across the Kennebec River between the Town of Moscow and Pleasant Ridge Plantation, Maine. The earthen embankment portion of the dam is approximately a half mile long and is a ~155 foot dam.
The existing earthen embankment of the Wyman Dam, from the east abutment to the concrete powerhouse structure, was too narrow for vehicles – particularly construction vehicles – to safely cross and once there, vehicles had no way to turn around.
SchonewaldEA worked directly with the facility owner to develop design and construction documents for widening the crest of the embankment dam and constructing a gravity block retaining wall to create a vehicle turnaround at the powerhouse. Design development included working with a local earthwork contractor to evaluate the performance of a locally available soil-rock fill material for use to widen the dam crest. Provided construction management/oversight and CQA/CQC documentation.
SchonewaldEA retained by NextEra Energy Resources
Instrumentation Support
Multiple Hydro Facilities, ME
Assisted NextEra Energy by managing, reducing, and reporting monthly instrumentation monitoring data collected in accordance with FERC license requirements for eight of their hydropower facilities located along the Androscoggin, Kennebec, and Saco Rivers in Maine.
SchonewaldEA retained by NextEra Energy Resources
Construction Support / Oversight at Multiple Hydro Facilities, ME
SchonewaldEA provided pre-construction and construction-phase support services at multiple hydropower facilities located throughout Maine.
Pre-construction work included:
- Preparation of construction design and/or bid documents
- Permitting associated with construction
- Preparing & presenting at preconstruction meetings
Construction-phase work included:
- Providing field support
- Construction oversight & quality assurance services
- Field design services
- Record document preparation
Projects included
- Draft tube replacement – Deer Rips Hydroelectric Plant, Androscoggin River, Auburn
- Hingeboard repairs – Shawmut Dam, Kennebec River, Fairfield
- Earthen embankment dam rehabilitation – Abbott Brook Dike on Aziscohos Lake
- Initial site work for dam reconstruction – Upper Dam on Mooselookmeguntic Lake
- Embankment dam remediation – East Outlet of Moosehead Lake
- Automated trash rake installation – Bonney Eagle Hydroelectric Project on the Saco River, Hollis
SchonewaldEA retained by FPL Energy Maine Hydro and NextEra Energy Resources
