Sigma creates stormwater plan for development

new berlin, wisconsin

The Sigma Group was retained by the City of New Berlin to provide professional engineering services for the development of a Regional Stormwater Management Plan for approximately 775 acres of land in the City.

The plan was developed to preserve and create environmental features in harmony with future development. Green infrastructure treatment train systems were evaluated in the context of utilizing and enhancing the surrounding environmental features. The plan addressed regional compliance with stormwater regulations as well as recommendations for individual onsite mitigation during development. Green roofs, rainwater harvesting, porous pavement, bioswales, and other innovative techniques were examined as part of the plan.

The project included:

  • Meetings, coordination, and planning with City of New Berlin
  • Identification of City, County, Regional (MMSD, SEWRPC), State (DNR) and Federal agency requirements
  • Collection and Review existing data including topography, roads, utilities, property boundaries, past studies, land use plan, wetlands, waterway, and floodplain
  • Development of Surface Water Management Goals and Policies to address water quality, water quantity, infiltration, flood protection, erosion/ sediment control, open space/recreation, wildlife habitat, streambank condition, and wetlands management
  • Conducting existing and future condition hydrologic and hydraulic modeling, and the associated development of stormwater management strategies for three alternatives:
  • Green Infrastructure/Low Impact Development Practices Only
  • Gray Infrastructure/Traditional Stormwater Management and Conveyance Only
  • Combination of Green and Gray Infrastructure
  • Opinion of probable construction and maintenance costs for alternatives.
  • Preparation of comprehensive stormwater management plan, documenting the findings, analysis, design criteria, and assumptions of each alternative and associated Best Management Practices (BMPs). The plan also documented potential funding sources for the implementation of the alternatives.