Stormwater Facilities
The function and appearance of stormwater facilities may differ, but their overall purposes are similar: to capture, clean, enhance infiltration into the ground, and/or release stormwater at an approved rate to control downstream flooding. Collectively, there are more than 460 stormwater facilities in Wentzville that help manage over 13 billion gallons of rainfall received, providing flood protection and improving water quality in accordance with state and federal laws.
Ownership & Maintenance
Annual maintenance and inspections are important to ensure the stormwater facilities are performing these tasks as designed. Generally, the City owns and maintains public infrastructure (i.e. residential piped infrastructure repair or blockage removal) and the property owner is responsible for private infrastructure and grounds maintenance (i.e. mowing, removing sediment/trash, or pond dredging).
What Type of Stormwater Facility Do You Have?
Traditional detention and retention basins provide flood control for our community. Newer stormwater quality facilities are also designed to treat runoff from development in accordance with the Clean Water Act. These most facilities in Wentzville have a recorded Stormwater Facility Maintenance Covenant that outlines the owner’s responsibilities. In addition, an Operation and Maintenance Plan was created for newer facilities to guide maintenance activities specific to your site. These stormwater quality facilities require an annual inspection to be submitted to the City by the property owner, read more about this below.
Types of Stormwater Facilities
Annual Inspections Required:
- Bioretention (Rain Gardens)
- Stormwater Ponds (WQ)
- Sand Filters
- Dry/Wet Swales
- Infiltration Systems
- Hydrodynamic Separators
- Pervious Pavements
Annual Inspections Recommended:
- Detention Basins
- Retention Basins (Ponds)
If you have questions about your facility type, maintenance or inspection requirements, or if you are interested in onsite inspection training, please contact the Stormwater Division at (636) 327-5101.
Water Quality Facilities
Over the last decade, newer facilities have been designed to improve water quality and/or help reduce erosion in streambank channels. These Stormwater Post-Construction BMPs (Best Management Practices) are now a requirement of state and federal Clean Water Laws.
For example, basins and ponds may have forebays to help settle out sediment or debris. Swales and sand filters are typically smaller and used to slow down and infiltrate runoff. Some facilities, such as bioswales and biofilters, mimic natural processes using vegetation, soils, and infiltration to filter pollutants and improve water quality. Proprietary BMPs, such as hydrodynamic separators, underground detention, and permeable pavement, use engineered processes to manage and treat stormwater.
Click the button below to learn more about the best management practices for stormwater facilities, including pollution prevention.
Inspection Information and Resources
Stormwater Quality Facility – Required Annual Inspections
As a part of continued maintenance responsibilities, owners must perform an annual inspection that logs maintenance and repairs performed and current owner contact information. Submit the report along with a current photo to the Wentzville Stormwater Division by August 31 each year to avoid compliance enforcement. Please contact the Stormwater Division at (636) 327-5101 with any questions.
NEW Online Inspection Portal Coming Soon!
Required annual inspections can be done from smartphone or tablet! Click the button below to navigate to the inspection portal.
The new inspection portal will be able to help you:
- Submit an inspection
- Identify what type of facilities are at your location
- Find documents such as design plans and covenants/legal documents (still in development)
- Update property contact information
- Request a site visit with a Stormwater Division employee
- View previous property owner inspections, see facility status and more
Submit an Inspection (Current Inspection Portal):
For proprietary BMPs, refer to your specific user manual and Operations & Maintenance Plan. The inspection form found in the manual/maintenance plan can be uploaded here.
Other Detention or Retention Basin – Inspections Recommended
Detention Basins
Traditional basins temporarily detain stormwater and release it at a reduced rate for flood control. Annual inspections and maintenance are recommended to ensure they function properly.
Retention Basins
Typically, these basins permanently hold water (as an amenity), while detaining and releasing additional flows at a reduced rate (for flood control). Annual inspections and maintenance are recommended to ensure they function properly. If your pond was designed more recently, it may also be a Post-Construction Water Quality BMP.
Inspections and Maintenance Report Forms
Resources
- Contractors List for Inspection & Maintenance
- Resources for Stormwater Facilities
- Native landscaping can help reduce long term maintenance costs. The following lists ways you can convert common ground into community assets. If interested, contact the Stormwater Division for assistance.
- Replacing turf grass with more aesthetic landscape of native plants; to ensure this complies with city mowing/weed ordinances, a city-approved landscape plan and maintenance agreement may be required. Native Landscaping Manual
- Providing trees and native landscaping along lakes to increase property value and provide fish habitat
- Turning detention basins into lakes or wetlands (requires prior approval by the Engineering Division)
- Weed Identification Guide
- Secret of My Soggy Success (Homeowners’ Association Symposium)
- Frequently Asked Questions (found at the bottom of the page)
- Report a Concern
- Technical Assistance – please call the Stormwater Division at (636) 327-5101.