Mitigation Management developed a compensatory mitigation restoration plan for the Etowah River Road Mitigation Bank in accordance with the following regulatory guidance/rules:
- Standard Operating Procedure, Compensatory Mitigation [March 2004] (“2004 SOP”),
- Compensatory Mitigation for Losses of Aquatic Resources [33 CFR Part 332, 73 FR 19594-19705, April 10, 2008] and [40 CFR Part 230] (“2008 Final Rule”).
The Etowah River Road Mitigation Bank (ERRMB) was authorized as a commercial mitigation bank to provide stream and wetland mitigation credits for sale within its designated service area to public and private permittees that receive a Section 404 permit authorization from the U.S. Army Corps of Engineers (USACE) and a Section 401 certification from the Georgia Environmental Protection Division (GEPD). The ERRMB may also be utilized by public and private permittees that require mitigation credits associated with stream buffer impacts based on the GEPD stream buffer variance mitigation guidance.
The Etowah River Road Mitigation Bank (ERRMB) is an approximately 175-acre site situated along the floodplain of the Etowah River. The site is located in Dawson County, Georgia within the Etowah River watershed (HUC 03150104). The majority of the ERRMB was historically used for agricultural purposes. These past historic agricultural activities created an extensive ditch system throughout the bank boundary. These ditches served to drain the historic slope hydrology driven wetlands that existed on the property. This led to the loss of a high level of historic wetland function (hydrology, vegetation, and soil dynamics). Additionally, the ditching of historic streams lead to a loss of stable habitat and an increase and downstream sediment contribution. This greatly effected populations of the endangered Cherokee Darter (Etheostoma scotti) located on site within Proctor Creek.
As part of the proposed ERRMB restoration plan, streams and their associated buffers were stabilized and restored. Reductions in sediment was achieved by restoring these ditched and channelized streams to their proper function through raising the channel beds and creating a stable pattern and dimension. Additionally, historic slope wetland systems were restored and enhanced through the channel restoration activities, backfilling historic agricultural ditches, and afforestation of both the wetland, riparian, and upland areas.
The goals of the ERRMB were to improve the resource functions of two unnamed tributaries and Proctor Creek through natural channel design as they descend through valleys and adjacent wetland systems. Additionally, goals also included the restoration of historic wetland function. Specifically, the goals of the ERRMB are:
Wetland restoration component:
- Restore historic hydrology
- Increase function as defined by HGM standards
- Enhance flood-flow attenuation
- Increase groundwater recharge
- Improve vegetative diversity
- Diversify vegetative stratums
- Increase hydrophytic vegetation
- Create stable habitat heterogeneity
Stream restoration component:
- Increase diversity of benthic organisms
- Increase diversity of EPT taxa
- Decrease percentage of generalist/herbivore fish species
- Increase epifaunal habitat availability
- Improve vegetative diversity in the riparian buffer
- Create varied vegetative stratums
- Decrease baseflow turbidity
- Decrease bank erosion rates
- Restore floodplain connectivity
- Attenuate storm flows.
- Decrease in-channel shear stress
- Increase median particle size
Ultimately, the organization was responsible for implementing the final restoration plan. This plan included:
- Approximately 5,549 LF of Priority 1/2/3 Stream Channel Restoration
- Installation of 21 Rock Vanes
- Installation 8 Brush Mattresses
- Installation 21 Toe Wood Structures
- Approximately 41,035 cubic yards of grading
- Backfilling of historic channels and ditches