NAHN & ASSOCIATES L.L.C.
Learn About Our Projects
Lakeview Park Sediment Basin
City of Middleton, 2011
Design of - acre sediment basin for stormwater quality purposes. Project involved diverting stormwater from an existing 54 inch storm sewer to a proposed wet detention basin in city park. Basin was sized to remove 73% of the incoming Total Suspended Solids (TSS) from 140 acres of primarily residential stormwater runoff. Project tasks included grant application and administration, permit preparation hydrologic and water quality modeling, preparation of plans and bid documents, bidding services and construction observation.
Harmony Grove Channel Restoration
Town of Lodi, 2012
Restore 5 channels by excavating sediment from channel bottom for navigational and fish habitat purposes. These channels had slowly filled in with sediment severely limiting boat access and fishing. 20,200 cubic yards of sediment was removed from 1.93 miles of channels using hydraulic excavating methods and geobags for sediment disposal. Project tasks included grant application and administration depth measurements, design of excavation plans and specifications showing existing and proposed channel depths and proposed sediment disposal area, pre- and post –excavation surveys: bidding services and construction observation.
Lakeside Park Channel Restoration
City of Fond du Lac, 2013
Restore 7 channels by excavating sediment from channel bottom in Lakeside Park. These channels had slowly filled in with sediment severely limiting boat access and fishing. 51,000 cubic yards of sediment was removed from 1.34 miles of lagoons using hydraulic excavating methods and geobags for sediment disposal. Project tasks included dredging feasibility report, depth measurements, design of excavation plans and specifications showing existing and proposed channel depths and proposed sediment disposal area, pre- and post –excavation surveys; and bidding services.
Baskerville Harbor / Pheasant Branch Creek Channel Restoration
City of Middleton, 2007
Restore lower section of Pheasant Branch Creek and portions of Lake Mendota within the City boundaries by excavating sediment from the bottom of the creek and lake. The project involved removing sediment from the City boat landing out to deeper water and a lower section of Pheasant Branch Creek. 6,500 cubic yards of sediment was excavated and removed using hydraulic methods and geobags for sediment disposal. Project tasks included preparation of dredging feasibility report, depth measurements, design of excavation plans and specifications showing existing and proposed channel depths and proposed sediment disposal area, pre- and post –excavation surveys; bidding services and construction observation.
Municipal Stormwater Discharge Permits
2004-2016
Assisted numerous towns and villages in complying with the requirements of their municipal stormwater discharge permit including Towns of Bristol, Cottage Grove, Dunn, Madison, Wilson, Oshkosh, Black Wolf and Village of Maple Bluff. Project tasks include preparation of Annual Report, illicit discharge monitoring, stormwater quality modeling (WinSLAMM), quarterly meetings and ordinance review and preparation.
Wolf Run Recreational Trails
Village and Town of Mazomanie, 2013-2014
Designed gravel trails to connect the Village of Mazomanie to Wisconsin Heights High School. Project involved boardwalk crossings of wetland areas, a wooden bridge over the Black Earth Creek, railroad crossing, several retaining walls and 1.28 miles of 10- foot wide gravel trails with 2 foot vegetated shoulders. Project allows school children to travel to school without having to drive on a dangerous section of U.S. Highway 14. Project tasks include preparation of design plans and specifications for bidding purposes, permit application and bidding services.
Middleton Beach Road Sustainable
Land Use Plan
City of Middleton, 2015
Developed a sustainable land use plan for future development including porous asphalt roads and pathways, fish rearing ponds and recreational trails in the Middleton Beach Road neighborhood (adjacent to Lake Mendota). Project tasks included preparation of conceptual plans for porous asphalt roadways and parking areas, neighborhood meetings and writing the land use plan.
Orchid Heights Park and Pond Restoration
City of Middleton, 2015-2016
Excavated two stormwater basins to improve stormwater quality. Two wet detention basins had slowly filled with sediment since construction in 1999. This project involved removing sediment from both ponds using dry mechanical methods and using the excavated soil to create soccer fields in the park. Both ponds were drained to a semi dry condition and excavated with bulldozers and backhoes.21,000 cubic yards of sediment was excavated and removed from these two basins.