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.
Apply for Commercial Site Plan
Apply for a Residential Site Plan
Apply for a Capital Improvement Project
Apply for a Grading Permit
Submit a Preliminary Plat
Submit a Record Plat
Apply for a Boundary Adjustment Plat
Apply for a Flood Plain Development Permit
Apply for a Driveway Permit
Apply for an Excavation Permit
Schedule an inspection
Downloadable Construction Plans
- Residential/Commercial Standard details (PDF)
- Grading Plan Standard details (PDF)
- Residential/Commercial/Grading CAD files (contains the above details on CAD format)
Concrete Pavement and the Eastern Missouri Pavement Consortium (EMPC)
All concrete placed within the City of O'Fallon must be submitted to and approved by the Eastern Missouri Pavement Consortium (EMPC). Approved mix designs will be stored on their website for use. Specifications for concrete pavement are also provided. Please reference the EMPC brochure (PDF) for additional information. Any new mix design that is submitted may take serveral weeks before approval is issued.
The website to access the EMPC is empcpavement.org. In order to view information on the website, a free account is required. An account can be created by clicking "Login" on the homepage.
Recently Adopted Ordinances
The City uses a third party company to publish updates to the City Code. These updates are only updated a few times per year. The ordinances below were approved recently, and will affect projects that require the Engineering department. Please refer to these updated ordinances. Once they are updated on the City Code, then they will be removed from this list. The full text of these ordinances is available here.
- Concrete Rock requirement - effective November 1, 2016 (Ordinance 6242; approved August 11, 2016)
- New FEMA floodplain maps may affect some residents (January 2016)
- See if a property is located in a floodplain
- Floodplain insurance
- Floodplain Development Permit Application (PDF)
- Professional Certification for LOMR Application (PDF)
- Why is my Flood Insurance Costing More? (The Biggert-Waters Flood Insurance Reform Act of 2012) and Elevation Certificates – Who Needs Them and Why
Learn how to apply for a permit when replacing, modifying or widening your driveway, including the process and standards set forth. Go to the Driveway Permits webpage.
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.
Interactive GIS Map
Some layers of the mapping system are featured in order to help provide some basic information to the public. Please note that the locations of the objects within this mapping system should be used for reference only. Field verification of the data may be needed. As well, some data may not be published for security reasons.
Contact Engineering staff