Sturkie Creek

Introduction

The Sturkie Creek Mitigation site has "excellent potential" to provide over 32,300 stream mitigation credits that may be used to mitigate mid to large size construction sites throughout the east central Alabama area as required by the U.S. Army Corps of Engineers.

Site Location

The Sturkie Creek Mitigation site is located near Lee Road 145 in Salem, Lee County, Alabama. The study area is approximately 96 acres in size and is located at latitude 32.592°North and longitude 85.255°West in Section 32, Township 19 North, Range 28 East. The site is bordered by forested property to the north and east, agricultural land to the south and residential lots to the west. The area is depicted on the Parkers Crossroads, Alabama Quadrangle, United States Geological Survey Topographic Map (7.5-minute series). The site is within the Middle Chattahoochee-Walter F. George Reservoir watershed (HUC 0313003).
 
Watershed Boundary

Habitat

At the time of the fieldwork, dense loblolly pine forest occupied a large portion of the site. An uneven-aged mixed forest occurred along the stream channels. Trees in this habitat included water oak (Quercus nigra), tuliptree (Liriodendron tulipifera), sweetgum (Liquidambar styraciflua), and red maple (Acer rubra). Scattered exotic species are present including Chinese privet (Ligustrum sinense), autumn olive (Elaeagnus umbellate), microstegium (Microstegium vimineum), and Japanese honeysuckle (Lonicera japonica). 

Jurisdictional Streams

Preliminary jurisdictional studies revealed five streams (Sturkie Creek and four tributaries) within the project boundaries. These streams total approximately 6,956 linear feet.

 
Jurisdictional Streams
Stream Hydrology Length (ft)
1 Intermittent 1,851
2 Intermittent 993
3 (Sturkie Creek) Perennial 2,250
4 Intermittent 1,581
5 Intermittent 281
  Total 6,956

 

Mitigation Potential

In-stream restoration involves the construction of a new stream channel that provides functions and values consistent with those of a stable, natural stream. Visual observation of channel geomorphology and Rosgen classification were used to identify stream reaches that are candidates for in-stream restoration.

 

Portions of Streams 1, 2, and 4, and all of Stream 3 were determined to be candidates for in-stream restoration according to guidance provided in the USACE’s “Standard Operating Procedure (SOP), Compensatory Stream Mitigation Guidelines (2009)”. In order to estimate the number of credits that may be generated, Stream Channel / Streambank Restoration and Relocation Worksheets were completed for appropriate stream reaches. In-stream restoration could generate approximately 20,690 stream credits. A summary of credits that may be generated is presented in Table 2.

 

Potential Stream Credits Generated
Stream Treatment Length (ft) M Score Credits
1 In-Stream Restoration 700 4.75 3,325
2 In-Stream Restoration 640 4.75 3,040
3 In-Stream Restoration 2,250 5.10 11,475
4 In-Stream Restoration 600 4.75 2,850
  Total 4,190   20,690

Riparian Mitigation Potential

Riparian mitigation consists of the preservation, enhancement, or restoration of riparian (streamside) forests in order to provide functions necessary for stable streams. An assessment of species composition within the riparian zone of each stream was conducted in order to determine the appropriate mitigation strategy for each stream reach.
It was determined that the riparian zones of Streams 1, 2, 4, and 5 are appropriate for riparian preservation. The riparian zone of Stream 3 is appropriate for riparian enhancement. Riparian buffers were configured to provide the maximum number of credits. In the case of overlapping buffers, which are not permitted, the buffer that produced more credits was selected. Therefore, no buffers were configured for Stream 5 as it lies within the buffers for Stream 4.

Potential Riparian Buffer Credits Generated
Stream Treatment Length (ft) M Score Credits
1 Riparian Preservation 1,851 0.70 1,295.7
2 Riparian Preservation 993 0.70 695.1
3 Riparian Enhancement 2,250 4.05 9,112.5
4 Riparian Preservation 741 0.70 518.7
  Total 5,835   11,622.0

 

Conclusion

The Salem Tract site has excellent potential to provide stream mitigation credits for USACE permits. The estimated amount of stream credits that could be generated on the site (32,312) is consistent with the range of credits that may be required for permits for large projects.

In-stream mitigation work would include restoring degraded stream channels to appropriate pattern and profile to maintain stable banks and create natural aquatic habitat.

Riparian buffer enhancement would require removal of exotic species, planting of appropriate native vegetation, and five years of biannual monitoring in addition to recording a restrictive covenant. Removal of exotic species may include use of a mulcher in certain areas as well as manual removal, followed by herbicide application. Upon removal of exotics, native vegetation would be planted. Potential plantings may be selected based on wildlife habitat value, aesthetic criteria and appropriateness for the understory or midstory of this riparian forest. Approximately 24 acres are candidates for riparian enhancement.

The Salem Tract site is located in the appropriate HUC8 watershed (Middle Chattahoochee-Walter F. George Reservoir) for developing areas in Phenix City, Alabama, and areas adjacent to Ft. Benning, Georgia that may experience development related to expansion of the military base and nearby municipalities. The site is outside but adjacent to the Lower Tallapoosa (Auburn, Montgomery, and western Opelika, Alabama) and Middle Chattahoochee- Lake Harding (Lanett, Valley and eastern Opelika, Alabama) HUC8 watersheds.