OMNNI Associates
OMNNI Services
OMNNI Services
OMNNI Services

Town of Grand Chute Mud Creek Stormwater Detention Pond,
Grand Chute, Wisconsin

Developed a hydrologic model using WMS and performed floodplain analysis using HEC-RAS for the 15.3-square-mile Mud Creek Watershed. Designed a 440 acre-foot detention facility with two 20,000-gpm pumps. Design also included a concrete spillway, hydraulic control structure, and mass grading plan (750,000 cubic yards of excavation). Worked closely with the Army Corps of Engineers for wetland mitigation permitting and with the Wisconsin Department of Natural Resources for permitting of channel improvements.

Designed a one-mile truck driving track around the detention pond for Fox Valley Technical College. Designed horizontal and vertical alignment and redesigned the stormwater pond to accommodate the driving track which included the compaction of 250,000 cubic yards of fill material.

Outagamie County Regional Airport,
Appleton, Wisconsin

OMNNI provided stormwater design and permitting services including:

  • Grading and drainage plans for runway, taxiway and apron improvements and expansions.
  • Open channel and storm sewer design.
  • Drainage study including evaluation of the runoff from the airport under predevelopment conditions, existing conditions, and conditions projected to exist in the year 2010. Preliminary plans were prepared for upgrading detention and drainage facilities to reduce runoff to predevelopment levels. Coordination with airport authorities, town, county and state officials and local landowners was required.
  • Established a hydrologic model for entire airport property including drainage to several watersheds. Evaluated eleven existing onsite detention facilities for effectiveness.

Plum Creek Floodplain Delineation,
Outagamie County, Wisconsin

OMNNI determined the 100-year water surface elevations and floodplain area for 15 stream miles of Plum Creek and its tributaries. OMNNI obtained recent LIDAR (Light Detection and Ranging) elevation data from Outagamie County and developed a detailed surface model of the watershed. The stream system was then modeled using HEC-GeoRAS, and HEC-RAS was used to calculate the 100-year water surface elevation at each cross section. The resulting floodplain was mapped in HEC-GeoRAS and submitted to the WDNR for approval. The use of LIDAR, GIS and HEC-GeoRAS allowed OMNNI to complete a detailed floodplain delineation of 20 stream miles in less time than it would take to complete one stream mile using traditional methods.