Engineering

The Engineering and Plan Review Group is responsible for the review and approval of commercial and residential plans, regulating development in the 100-year floodplain, issuing utility excavation permits, and working with residents, developers, and engineers on wastewater, stormwater, and drinking water issues, along with review of all Planning & Zoning Commission submittals.

The division is also responsible for developing and implementing the City’s Traffic Management Code.

Find out more about the I-70 Improvement Project through O'Fallon.
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Downloadable Construction Plans

Residential and Commerical Sudivision Plans (Download)

  • Residential Plan Instructions
  • Cover sheet Residential
  • Residental Notes
  • Erosion Detail
  • Storm & Sanitary Detail
  • Water Detail 1
  • Water Detail 2
  • Pavement Detail 1
  • Pavement Detail 2

Commercial and Industrial Site Plans (Download)

  • Commercial Plan Instructions
  • Cover Sheet Commercial
  • Commercial Notes
  • Erosion Details
  • Storm & Sanitary Details
  • Water Detail 1
  • Water Detail 2
  • Pavement Detail 1
  • Pavement Detail 2

Grading Plans (Download)

  • Grading Plan Instructions
  • Cover Sheet Grading
  • Grading Notes
  • Erosion Details

Important floodplain information


Contact Engineering staff

General Assistance This email address is being protected from spambots. You need JavaScript enabled to view it. 636-379-5596
Aubrey Hawley, Administrative Assistant This email address is being protected from spambots. You need JavaScript enabled to view it. 636-379-5596

Construction Inspection

This division's purpose is to review and conduct residential and commercial construction inspections of storm sewers, sanitary sewers, water mains, streets, grading, and other site development items assuring for code and approved construction plan compliance and quality of construction.

Are you a resident with a question about your final infrastructure inspection? Send an e-mail to This email address is being protected from spambots. You need JavaScript enabled to view it. .