Detention Basin & Stormwater Management Facility Maintenance


With the growth of St. Charles County, increased storm water runoff has an impact on our streams, environment, and quality of life. Increased storm water runoff causes more flooding problems as well as accelerating erosion to and causing degradation of our natural watercourses and creeks. This affects all homeowners within the watershed, both upstream and especially those that live at the lower end of the watershed.

One method required to help control the rate of storm water runoff from any developing site is the design and construction of storm water detention basins. These basins are designed to limit the amount of flow that can be discharged through them while temporarily storing the remaining amount of runoff water that is discharged into them until it can be released at the slower rate.

Practices to reduce the volume of storm water runoff and to filter pollutants from the runoff may also be approved or required for use by the county. Storm water management facilities can be designed to infiltrate storm water runoff back into the ground; thereby reducing the volume of water discharged into streams. Facilities can also be designed to intercept and filter pollutants from the runoff.

Maintenance requirements

In unincorporated St. Charles County, the maintenance responsibility for detention basins and storm water management facilities lies with the subdivision homeowners in residential subdivisions, usually through their board of trustees, and with the property owner(s) on commercial sites and private properties.

It is critical that detention basins and storm water management facilities are properly maintained and to help ensure that they are, the county established an ordinance requiring the routine inspection of such facilities effective Jan. 1, 2006. Section 420.020 of the County ordinances regulates the need to record, inspect, and require maintenance and repair to all of these facilities within the unincorporated county.

Ensuring periodic maintenance and repair of detention basins and storm water management facilities will help reduce the impacts of flooding and erosion in the natural watercourses and streams and provide a greater quality of life for all stakeholders in the watershed.

Inspections & enforcement
The Development Review Division of the Community Development Department is responsible for the maintenance inspection and enforcement of all detention basins and storm water management facilities within the unincorporated county.  The division inspects all detention basins a minimum of once every five years.  After a County inspection, the responsible party(ies) will receive a Detention Basin Inspection Form (PDF) or a Storm Water Management Facility Inspection Form to let them know if there are any deficiencies within the basin or facility.

If deficiencies are found, a corrective action plan will be required to be submitted within 20 days of the notification that addresses and sets deadlines for correcting the deficiencies.  If compliance is not achieved within the allotted time frame, the county can institute an appropriate action for fines and injunctive relief or it can have the deficiencies corrected and assess a special tax lien against the owner of the basin.


Please contact the St. Charles County Development Review Division at 636-949-1814 or email the Development Review Division.