Olmsted County CSAH 22 Extension & CSAH 33 Reconstruction

Rochester, Minnesota

SRF was selected to provide engineering design services to Olmsted County for the roadway reconstruction and new alignment of a portion of CSAH 22  (55th Street) in Rochester, Minnesota. SRF was responsible for right-of-way acquisition, utility coordination, environmental documentation, drainage design, signal design roadway design, wetland impacts, permitting, hydraulic modeling, and bridge design. The project was recognized by ACEC Minnesota with an honor award in 2019.

The new road alignment extends from West River Road Northwest to North Broadway and includes the reconstruction of more than two miles of four-lane roadway. The roadway design included the following design elements: Concrete paving, ADA/trails, park and local access connections, rock excavation, and utility design (water main and sanitary sewer). To date, the 55th Street Extension project is the largest project completely funded by a county, outside of the twin cities metro area, in the state of Minnesota with a construction cost of $32.8M.

A prominent design feature on the project is the new bridge over the south fork of the Zumbro River, which is approximately 474 feet long. The crossing location required thorough scour analysis to aid in footing design, and a FEMA Letter of Map Revision (LOMR). SRF’s Water Resources and Structures teams worked to refine the bridge design and identify a sound, cost effective alternative. In addition, the teams collaborated on four new culvert designs consisting of multi-cell precast concrete box culvert sections.

SRF’s environmental planners assisted Olmsted County with the environmental review process, including the preparation of a State Environmental Assessment Worksheet (EAW).

SRF was responsible for the following tasks:

  • Broadway Avenue North Access Study
  • Layout for Municipal Consent
  • Traffic Analysis Review
  • Signal Justification Reports
  • Hydraulic Memos (Box Culverts)
  • NPDES Permit
  • Wetland Permits (WCA and Section 404)
  • Report of Geotechnical Exploration and Review
  • Environmental Assessment Worksheet (EAW)
  • Final Roadway/Grading Plans, Specifications, and Estimates
  • Final Bridge Plans, Specifications, and Estimates


Olmsted County