Watercourse Protection

It is the policy of St. Charles County to protect and maintain the native vegetation adjacent to natural watercourses by implementing specifications for the establishment, protection and maintenance of a vegetated buffer along all natural watercourses under St. Charles County’s jurisdiction that are left in their natural state.

Current code

Chapter 405, Article VI in the County ordinances provides regulations for the protection of natural watercourses within the unincorporated county. Section 405.060 defines a Natural Watercourse as a channel formed in the existing surface topography of the earth prior to changes made by unnatural conditions and it defines a Channel as a natural or artificial watercourse of perceptible extent, with definite beds and banks to confine and conduct continuously or periodically flowing water. 

Protected watercourses

The ordinance requires that all natural watercourses that are depicted on the most current United States Geological Survey 7.5 Minutes Series (Topographic) Maps must be left in their natural state.

Vegetated buffers 
The ordinance requires that all natural watercourses that are left in their natural state be flanked with vegetated buffers. Within all vegetated buffers there shall be no clearing, grading, construction, or disturbance of vegetation except as permitted by Section 405.5026 of the County Codes.

 Minimum buffer widths of 50 feet are required along the main branches of Dardenne Creek, Peruque Creek, Femme Osage Creek, Big Creek, and McCoy Creek and 25 feet along all other natural watercourses left in their natural state. The vegetated buffer (setback) shall begin at the edge of the bank of the natural watercourse.

Berms & dams 
This ordinance also regulates the removal or installation of berms and dams across natural watercourses. Removal or installation of dams across watercourses depicted on USGS topographic maps must be approved by the County Council per Section 405.5026.A. Removal or installation of dams across watercourses not depicted on USGS topographic maps must be approved by the Director of Community Development per Section 405.5026.B.5.  A separate permit is required for the installation or removal of Water Reservoirs/Dams.

Natural Watercourse Permit
Learn more about the process to obtain a Natural Watercourse Permit.

Federal & state permits
Permits are also required from the United States Army Corps of Engineers (404 - wetlands) for any impacts to Waters of the United States and from the Missouri Department of Natural Resources (401 – water quality certification) for any impacts to Waters of the State.

Benefits
Vegetated buffers adjacent to natural watercourses provide numerous environmental protection and resource management benefits that can include:

• Allowing for the natural meandering of natural watercourses reducing the likelihood of infrastructure and property damage and minimizing the need for costly engineering solutions to erosion problems
• Furnishing recreational opportunities
• Minimizing encroachment
• Providing infiltration areas for storm water runoff
• Providing tree canopy, organic matter, and habitat for wildlife
• Reducing flood impacts
• Reduction of sediment transportation and erosion
• Removing pollutants from storm water
• Slowing the velocity of floodwaters
• Stabilizing stream banks