WisDOT, in conjunction with the City of Brookfield (City), is developing proposed improvements for a 2.1-mile section of Calhoun Road from CTH M (North Avenue) to STH 190 (Capitol Drive) in the City of Brookfield. Currently, Calhoun Road is a rural two-lane roadway with 6 to 8-foot wide gravel shoulders and ditches for roadway drainage. The City and WisDOT are proposing to expand Calhoun Road to an urban four-lane roadway that is divided by a raised median.
During the initial planning of the project in 2016, the raSmith ecological team was retained by the City to complete a wetland delineation within the transportation corridor. The wetland delineation consisted of a review of available maps and information followed by fieldwork in October 2016 to document field conditions. The presence and absence of hydrophytic vegetation, wetland hydrology and hydric soil indicators were documented using methodology defined in the US Army Corps of Engineers (USACE) 1987 Wetland Delineation Manual, Regional Supplement to the 1987 Corps of Engineers Wetland Delineation Manual: Midwest Region (USACE ERDC, 2010) and Guidance for Submittal of Delineation Reports to the St. Paul District Army Corps of Engineers and the Wisconsin Department of Natural Resources (USACE St. Paul District, 2015). Thirteen wetlands totaling 4.3 acres were delineated within the project corridor. Two waterways and one excavated landscape pond within a mapped hydric soil unit were also identified.
As part of the due diligence process for this project, WisDOT requested concurrence with effects determinations of “May Affect, Not Likely to Adversely Affect” the Federally-Endangered Rusty Patch Bumblebee (RPBB – Bombus ifinis) RPBB, in accordance with Section 7 of the Endangered Species Act (ESA). Initial assessments did not identify RPBB as having critical habitat within the project area. However, in February 2020, the High Potential Zone (HPZ) for the RPBB was updated and was found to intersect the project area. The ecological team at raSmith prepared a summary assessment of the existing habitat accompanied by RPBB habitat maps showing the total area of habitat proposed to be impacted. It was determined that only low quality degraded habitat will be impacted by the project and will be mitigated by replanting with a pollinator seed mix after project construction.