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STATE OF NORTH CAROLINA (2111
DEPARTMENT OF TRANSPORTATION
MICHAEL F. EASLEY LYNDO TIPPETT
GOVERNOR SECRETARY
April 3, 2008
Mr. Doug Huggett
NC Division of Coastal Management
Parker Lincoln Building
2728 Capital Boulevard
Raleigh, NC 27604
Re: Sawmill Mitigation Site, Craven County, State Project No. 8.1170801, TIP Nos.
B-2531WM, Action ID No. 199401568, CAMA Permit No. 81-95, DWQ Project No.
95123 (Certification No. 2997)
Mr. Huggett:
As you are aware, the Department has monitored the Sawmill Mitigation Site since construction
in March of 2003. The site is located in Craven County, under the US 17 Neuse River Bridge
and adjacent to Howell Road in New Bern. The Sawmill Mitigation Site provides compensatory
mitigation for impacts associated with the construction of the Neuse River Bridge (TIP No. B-
2531). The 4.07 acre site includes both preservation and restoration of brackish tidal marsh as
well as tidal cypress-gum swamp. The entire site was planted and hydrologic monitoring gauges
were set in April of 2003. NCDOT proposed to monitor the Sawmill mitigation site for five
years or until success criteria were met; with both hydrological and vegetation monitoring
conducted each year. 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 ldoh/preconstruct/pe/neu/Monitoring/MonitorinZReports html
Hydrologic success criteria states that the site must demonstrate hydrologic frequency, duration,
and depth consistently within 10% of the hydrology of the reference areas. The site specific
criteria vary from the current federal guidelines that require a site to be inundated or saturated
(within 12" of the surface) by surface or groundwater for a consecutive 12.5% of the growing
season. 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: 919-715-1334 LOCATION:
NC DEPARTMENT OF TRANSPORTATION FAX: 919-715-5501 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 Hydrologic Monitoring Data, 2003-2007
Monitoring 2003 2004 2005 2006 2007
-Gauge Results Results Results Results Results
S-GW i . REF 75.5 94? 60.3 97.9 100.0
.S-GW2 EF) 75.8 100.0 100 0 68.2 100.0
S-GW3 75.8 42.9 71.5 100.0 28.0
S-GW4 75.8 100.0 95.0 100.0 45.0
S-GW5 68.2 50.0 78.1 100.0 36.0
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 541 trees per acre surviving, well above the minimum requirement of 260 trees per acre.
After five years of brackish tidal marsh vegetation monitoring, vegetation data for 2007 indicates
that the site has met the 70% frequency of targeted species criteria by yielding 100.0%. The
vegetative cover scale value of 4.5 is very close to meeting the requirement of 5.0 for year five.
Individual vegetation monitoring data 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 (919) 715-1425.
Sincerely,
Philip S. Harris, 111, P.E., Unit Head
PDEA-Natural Environment Unit
cc: Mr. William Wescott, ACOE
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