The reclamation of the Flambeau Copper Mine, located along the shoreline of the scenic and recreationally important Flambeau River in northern Wisconsin, presented technical and social challenges. AES planned, designed, and implemented the surface reclamation for the 180-acre site where copper, gold and silver had been mined since 1994.
Due to its proximity to the river, the potential for acid rock drainage, and persistent opposition to the project, the Flambeau Mine was highly scrutinized by a concerned public.
As a condition of closure prior to surface reclamation, the open pit mine was backfilled with originally sequenced waste rock mixed with limestone to neutralize acidity. The neutralized waste rock was capped with naturally occurring clay, overlain with native till, graded to a geomorphically accurate surface replete with a stable drainage network, and finished with salvaged topsoil.
AES designed a natural swale and biofilter complex to manage stormwater runoff prior to discharge into the Flambeau River. The bioengineered system not only treated runoff on-site, but also restored wetland habitat and enhanced the biodiversity of the reclaimed area.
Re-vegetation plans were designed to restore native plant communities and diverse habitat to the site. The design incorporated an on-site nursery to provide local native plant materials for restoration, as well as a hydric soil repository. Ten native ecological communities ranging from wetlands to upland prairie and savanna were planted in phases. The design also integrated several community engagement opportunities including high school students growing and installing native plants.
To successfully accommodate a complex planting plan and high species diversity, AES employed a variety of live plant installation and seeding strategies. These included hydro-seeding, drilling, cyclone seeding, hand seeding, transplanting, hand plugging and live staking. The site was ecologically managed with prescribed fire and invasive species control. Approximately 150 acres were restored to natural conditions and 30 acres were reserved for the development of a light industrial park that re-purposed the existing infrastructure.
After a period of intense monitoring and a certificate of successful reclamation and closure, the Flambeau Mine site serves as a valued asset for the public. Neighboring schools use the site as an outdoor classroom, residents of nearby communities appreciate the recreational nature trails, and businesses and government agencies occupy the industrial park.
By using ecological landscape design, AES was able to transform the former contentious open pit mine along the Flambeau River into a prized community resource.
- Mine Reclamation Design
- Permitting Assistance
- Stormwater Management Design
- Restoration Implementation
- Construction Oversight
- Operations + Maintenance
- Compliance Monitoring