19990929 Ver 1_Other Agency Comments_20080407

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STATE OF NORTH CAROLINA
DEPARTMENT OF TRANSPORTATION
MICHAEL F. EASLEY
GOVERNOR
April 3, 2008
Mr. William Wescott
Washington Regulatory Office ACOE
P.O. Box 1000
Washington, NC 27889-1000
LYNDO TIPPETT
SECRETARY
Re: Southwest Creek Mitigation Site, Lenoir County, State Project No. 6.201017, TIP No.
R-2001B; Action ID No. 199705426, DWQ WQC #. 990929
Mr. Wescott:
As you are aware, the Department has monitored the Southwest Creek Mitigation Site since its
construction in March of 2003. The site is located in Lenoir County, adjacent to the NC 11
bypass and just north of South Lenoir high school in the old NC 11 roadbed. The Southwest
Creek Mitigation Site provides compensatory mitigation for impacts associated with the
construction of the NC 11 Deep Run Bypass (TIP No. R-2001 B). The site provides 43.1 acres of
wetland preservation, approximately 3.61 acres of wetland restoration and includes both
bottomland hardwood and freshwater marsh communities. Following site grading, the entire site
was planted with bottomland hardwood trees. Hydrologic monitoring gauges were set in April
and May of 2003. NCDOT proposed to monitor the Southwest Creek mitigation site for five
years or until success criteria were met; with both hydrological and vegetation monitoring
conducted annually. After each growing season, annual monitoring reports were submitted to the
appropriate regulatory agencies via the Natural Environment Unit's (NEU) website:
http://www.ncdot.or,z/dohlpreconstructIDelneu/MonitoringIMonitorinzReports html
Hydrologic success criteria states that the site must be inundated or saturated (within 12 inches of
the surface) by surface or groundwater for at least a consecutive 12.5% of the growing season
during years of normal rainfall. As stated in the mitigation plan, the success of the restored
marsh will be determined by comparing the hydrologic data to that recorded within the reference
marsh system adjacent to the site. Surface gauges were also set at the site to determine the
frequency of inundation patterns. Table 1 provides a summary of the hydrologic data (the
percentage of the growing season that saturation was indicated) at each groundwater gauge
location for the past five years of monitoring.
MAILING ADDRESS: TELEPHONE: [phone] LOCATION:
NC DEPARTMENT OF TRANSPORTATION FAX: [phone] PARKER LINCOLN BUILDING
PROJECT DEVELOPMENT AND ENVIRONMENTAL ANALYSIS 2728-168 CAPITAL BOULEVARD
1598 MAIL SERVICE CENTER WEBSITE.' WWW.NCDOT.ORG RALEIGH, NC 27604
RALEIGH NC 27699-1598
Table 1. Summary of Hvdroloaic Monitorinu Data. 2003-2007
Monitoring 2003 2004 '2005 2006 - j 007
Gauge Results Results Results Results Results
SW-GW1 75.4 38.9 36.9 46.1 17.6
SW-GW2 75.4 35.6 76.6 31.1 3.7
Climate Average Average Average Average Below
Conditions Rainfall Rainfall Rainfall Rainfall Average
Rainfall
After five years of bottomland hardwood vegetation monitoring, vegetation data for 2007
indicates that the site has met vegetative success criteria by yielding an average tree stem density
of 680 trees per acre surviving, well above the minimum requirement of 260 trees per acre.
Individual vegetation monitoring data for is provided within the annual monitoring reports
submitted between 2003 and 2007.
NCDOT requests that the appropriate resource agencies provide written documentation stating
that no further monitoring is required and that the site is closed. If you have any questions about
this project, please contact Mr. Randy Griffin at [phone].
Sincerely,
Philip S. Harris, III, P.E., Unit Head
PDEA-Natural Environment Unit
cc: Mr. David Wainwright, DWQ
Mr. Travis Wilson, WRC
Ms. Kathy Matthews, EPA
Mr. Gary Jordan, USFWS
Mr. David Harris, P.E., NCDOT-REU
Mr. Jay Johnson, NCDOT-DEO