Driveway Stream Crossing Procedures

The following is a breif summary of requirements for residential crossings over state’s waters with a bridge or culvert.  At a minimimum, a lot grading plan (LGP) with grading, drainage, erosion control measures, and permanent design for the stream crossing is required.  Additional comments may apply. 

If the disturbance is greater than 1 acre, a full land disturbance permit (LDP) will be required. 

Areas containing FEMA or Cherokee County Future Conditions Floodplain require special consideration.  Per ordinance, access must be 3 feet about FEMA or 1 foot above Future Conditions floodplain elevations, whichever is higher.  

Culvert Crossing

1.  A Georgia Registered civil engineering or surveying consultant shall prepare a design with plans for the culvert crossing with all applicable calculations for the 100-year storm including erosion control measures for the stream crossing (pipe size, lengths, type, slope, etc).
2. Note that the design is subject to a plan review fee. 
3. A Georgia Registered civil engineering or surveying consultant shall prepare a pre-construction notification (PCN) for the U.S. Army Corps of Engineers (USACE) and obtain associated approval if applicable. 
4. We recommend obtaining at least 3 bids on the plans, hydrology study (calculations), and PCN preparation/approval from a civil engineering or surveying consultant.

Bridge Crossing

1. If you plan to build a bridge, a civil engineering consultant will need to determine the 100 year elevation of the creek; the bridge decking will need to above that elevation, with the travel lane 1’ above the 100 year BFE.  You may use the Cherokee County Floodplain Elevation if desired
2. A structural design on the bridge prepared by a Georgia Registered civil engineering consultant.
3. Erosion control design is also required.
4.  Note that the design is subject to a plan review fee.  
5. We recommend obtaining at least 3 bids on the plans, hydrology study, & structural design/calculations from a civil engineering consultant
6. Structural calculations for bridges will be reviewed by a third-party engineer at the applicant's cost. 

It should be noted that USACE recently revised its regional conditions; additional information may be obtained from the USACE's Savannah District Website:

https://www.sas.usace.army.mil/Missions/Regulatory/Permitting/General-Permits/Nationwide-Permits/

A PCN is required for use of any NWP that results in temporary and/or permanent adverse effects to 0.1 acre or more of wetlands, other special aquatic sites, and other waters (such as lakes and ponds), or 0.01 acre of perennial and intermittent stream.

That is 0.01 acre below the ordinary high water mark (OHWM).  This is measured by the ordinary high-water mark (OHWM) times the linear feet of impact.  

For all crossings, cross-sections at the stream with the 100-year HW elevation, 25-year HW elevation, wrested vegetation, top of bank, ordinary high-water mark (OHWM) should be provided.  These items are required to demonstrate compliance with recently revised USACE regional conditions

Note: If the pipe is not in states’ waters, the pipe size should be submitted to the Engineering Department for review and approval.  The 25-year event may be utilized for the sizing.  An erosion permit will be required for the installation.  Questions should be forwarded to either of the following

Ben Morgan, PE, CFM
Cherokee County Engineering
1130 Bluffs Parkway
Canton, GA 30114
Direct: 678-493-6074
Fax:  678-493-6088
[email protected]

Andrea Yager
Cherokee County Engineering
1130 Bluffs Parkway
Canton, GA 30114
Direct: 678-493-6060
Fax:  678-493-6088
[email protected]