20030147 Ver 2_Staff Comments_20070817

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MEMO
TO: Coleen Sullins
THROUGH: Tom Reeder
Michael F. Easley, Governor
William G. Ross Jr., Secretary
North Carolina Department of Environment and Natural Resources
Coleen H. Sullins, Director
Division of Water Quality
August 17, 2007
Paul Rawls
FROM: John Dorn
RE: Approval of policy gu nce on Stream Mitigation for FERC-related 401 Certifications
The attached guidance was developed with the NC Division of Water Resources and DWQ staff with
input from Progress Energy and Duke Power as well as the private banking community. The goal of the
guidance is to address how hydroelectric projects can use stream and buffer preservation to offset unavoidable
impacts to streams and rivers during the 404 Certification process for FERC (Federal Energy Regulatory
Commission) relicensing. This policy was put out to public comment through our mailing list on March 12,
2007 and we did not receive any public comment on the proposed policy. I can be reached at 919-733-9646 if
you have any questions.
_ Ane C~Ollna
~Ellrally
Wetlands and Stormwater Branch 1617 Mail Service Center Raleigh, NC 27699-1617 Phone [phone]
Internet: h2o.enr,state.nc.us 512 N. Salisbury St. Raleigh, NC 27604 FAX [phone]
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North Carolina Department of Environment and Natural Resources
Michael F. Easley, Governor
Division of Water Quality
William G. Ross, Jr., Secretary
Coleen Sullins, Director
MEMO
TO: Interested Parties
FROM: Coleen Sullins, Director
RE: Stream Mitigation for FERC-related 401 Certifications
Internal DWQ Guidance, NC Division of Water Quality, Version 1.5
DATE: August 24, 2007
The following policy is hereby approved for use by DWQ staff and the public when
reviewing or commenting on 401 Water Quality Certifications (15A NCAC 2H .0500) for FERC
(Federal Energy Regulatory Commission) permits and relicensing. This policy was sent to
public comment on March 12, 2007. This policy is effective upon the signature date. If you
have any questions about this policy, please contact John Dorney of my staff at 919-733-9646.
Regulatory background
The Division of Water Quality must issue 401 Water Quality Certifications for FERC
licenses and has done so for several years. The review process that DWQ uses is
outlined in the 401 Water Quality Certification rules (15A NCAC 2H .0500) and
generally follows the 404(b)(1) guidelines -namely, 1) avoid the impact, then 2)
minimize the impact to the maximum extent practical and then 3) finally, mitigate for
unavoidable impacts. The following guidelines assume that the FERC project has
been reviewed for avoidance and minimization and that the remaining unavoidable
impacts to stream channels are to be addressed through compensatory stream
mitigation. In some cases, stream restoration or enhancement can be done to
replace the unavoidably lost uses. The process for these practices is well outlined in
various documents but primarily in the joint state/federal stream mitigation guidelines
(US Army Corps of Engineers 2003). These guidelines state that stream restoration
is generally the preferred approach. In other situations, preservation of streams,
their adjacent buffers or perhaps entire watersheds can be acceptable alternatives.
This guidance focuses on the preservation option in order to provide additional
details to DWQ staff and the regulated community on this approach for FERC
relicensing. These guidelines are advisory and present DWQ's preferred approach
to meet this regulatory requirement. If applicants can demonstrate an alternative
way that adequately addresses these regulatory issues, then DWQ will carefully
consider all proposed alternative approaches.
401 Wetlands Certification Unit
1650 Mail Service Center, Raleigh, North Carolina 27699-1650
2321 Crabtree Boulevard, Suite 250, Raleigh, North Carolina 27604
Phone: [phone] FAX [phone] Internet: http://h2o.enr.state.nc.us/ncwetlands
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NorthCarolina
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II. Stream buffers and water quality
From a review of the scientific literature, it is clear that wooded stream buffers
provide essential water quality benefits to the adjacent stream. Indeed, stream
restoration and enhancement projects in NC have always required restoration or
enhancement of the stream buffers (generally, 50 feet in the piedmont and coastal
plain or 30 feet in the mountains). There is also a positive relationship between the
width of the stream buffer and the degree of water quality benefit whereby a larger
buffer has greater water quality benefit. However, the relationship is not linear.
Above a certain buffer width, increases in water quality benefits tend to level off.
From analysis of scientific literature on buffer width and pollutant removal (Figures 1,
2 and 3 in Appendix 2), the incremental water quality benefits of stream buffers wider
than 50 feet tend to be relatively small. It should be noted that the sediment removal
curve (Figure 2) provides support for buffers greater than 50 feet and up to 100 feet
wide. Several comprehensive reviews of the buffer literature (Castelle, et. al. 1994,
Doohaluk 2000 and Wenger 1999) suggest that a 100 foot buffer is important for
long-term water quality protection since most of the studies that are reflected in
Figures 1 - 3 Appendix 2) are based on short-term research. Therefore, DWQ
believes that protected buffers of 50 feet should generally be the minimal width but
that protected buffers of 100 feet should be encouraged and receive more beneficial
credit ratios.
III. Existing state/federal stream mitigation guidelines
In 2003, the state and federal regulatory agencies developed and adopted the
"Stream Mitigation Guidelines" (April 2003) to provide guidance to the US Army
Corps of Engineers, US Environmental Protection Agency, NC Wildlife Resources
Commission and NC Division of Water Quality as well as the regulated community in
our review and approval of stream mitigation projects. These guidelines are
intended to be used for 404 and 401 permitting decisions but also provide a useful
framework for FERC-related stream mitigation issues.
The guidelines define four types of stream mitigation (Restoration, Enhancement
Level I, Enhancement Level II and Preservation) with corresponding mitigation ratios
(1:1, 1.5:1, 2.5:1 and 5:1, respectively). Preservation sites must meet the criteria
shown on page 16 of this document. Foremost in those criteria is that in addition to
the biological value of the streams, the site must be in an area with threats to
development (see Appendix 1). In many cases for FERC permits, preservation is a
viable option to provide mitigation for unavoidably reduced stream flow. The
following guidance is intended to expand upon the Stream Mitigation Guidelines in
the FERC-context. DWQ intends to open discussions with the other state and
federal agencies to include these items in a revised Stream Mitigation Guidelines
once we have more experience with these issues in the FERC-context. Additionally
if stream buffers can only be protected on one side of a stream, then only one-half
the credit is available. Finally, if an existing regulatory buffer exists, then any
additional buffer must go beyond the protected buffer in order to count at a reduced
ratio for mitigation credit.
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IV. Proposed policy
a. Demonstrable threat
Sites proposed for preservation must have a demonstrable threat as defined in
Appendix 1. This definition was developed for and approved by the Performance
Assessment and Consistency Group (PACG) by the relevant state and federal
agencies including DWQ. Written documentation of the demonstrable threat to a
particular site or group of sites is needed before a preservation site can be
approved by DWQ.
b. Preservation mechanism
Preservation should be fee simple acquisition with title given to a relevant state
or federal land management agency or responsible local conservation group
(non-governmental organization) such as The Nature Conservancy or local land
trust. A conservation easement shall also be provided with the land. Provisions
for land management, access and other activities shall be clearly spelled out in
the conservation easement using guidance available from agencies such as the
US Army Corps of Engineers, EEP or the Clean Water Management Trust Fund.
c. Preservation of 100 foot stream buffers
Preservation of 100 foot stream buffers shall receive a 4:1 mitigation ratio since
preservation of this wider buffer is more important to water quality than
preservation of the typical 50 foot buffer.
d. Preservation of entire watersheds
Preservation of an entire local watershed surrounding a particular stream
channel shall receive a 3:1 mitigation ratio for the length of streams in the
watershed since preservation of the entire watershed will protect water quality in
these streams in perpetuity. Protection of the entire watershed provides longer
term water quality benefits than protection of 50 or 100 foot buffers.
e. Example (hypothetical,~
The following example (Figure 4) is provided to illustrate the use of the above
preservation ratios. This example is hypothetical and is therefore not based on a
particular site. This example assumes that the site has a demonstrable threat
and that a fee simple acquisition is contemplated with a conservation easement.
In this example, there are 10,000 feet of unavoidable stream impact for a
particular project. A proposed mitigation package includes 24,000 feet of stream
in Parcel A and 9,000 feet of streams outside Parcel A. We will presume that an
applicant propose to preserve the entirety of Parcel A as well as 100 foot wide
buffers along 4,000 feet of streams outside Parcel A and 100 foot wide buffers
along 5,000 feet of streams outside Parcel A. The following amount of stream
credit would then be available for this proposal:

Table 1: Stream mitigation credits from different types of stream
preservation assuming impact and mitigation sites are within one stream
order of each other. This example assumes 10,000 feet of stream
mitigation is required.
Type of Length of Mitigation
Preservation streams (feet) Mitigation Ratio Credits
Watershed 24,000 3:1 8
000 foot-credits
preservation ,
100 foot wide 4
000 4:1 1
000
buffers , ,
50 foot wide 5
000 5:1 1
000
buffers , ,
Totals 33,000 10,000 credits
Therefore this proposed stream mitigation package provides sufficient
compensatory mitigation for the 10,000 feet of stream impact assuming that
stream size considerations (discussed below) are met.
Stream size considerations
The Stream Mitigation Guidelines state that mitigation should be within one
stream order of the impact. In many cases for FERC projects, mitigation will
need to be done for larger stream impacts with preservation on smaller stream
channels. A strong effort should be made to provide mitigation for larger order
streams (third and up) with large streams (third order or up) and for smaller
streams (first and second order) with smaller streams. When this is not possible,
the applicant must provide written justification that the proposed mitigation will
adequately replace lost aquatic life functions. Finally, preservation should focus
on the perennial stream segments rather than the intermittent segments unless
the impact is on intermittent streams.
g. Statistically-based estimates of stream length
Once the above calculations are made to determine the amount of mitigation
requirement for a particular project, it will be necessary to tally the length of
stream on a particular site. If an exact stream length can be readily determined
in the field, this is the preferred approach. If questions arise as to whether a
particular feature is a stream or not, then NC DWQ's "Identification Methods for
the Origins of Intermittent and Perennial Streams" (Version 3.1; January 1, 2005)
should be used to make this determination.
However in many cases of watershed preservation, it is not practical to map all
the streams found in the watershed. Unfortunately there are no available maps
which accurately depict stream length in NC. As an initial, rough estimate, the
length of stream shown on the 1:24,000 USGS topographic maps can be used
along with regional correction data. However for a specific mitigation proposal, a
more accurate determination of stream length is required.
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In lieu of comprehensive mapping of watersheds, it may be possible to collect
statistically-based estimates of stream length as long as the preservation sites
are similar in geology and topography. DWQ would need to approve this study
design which should be based on the on-going stream mapping effort
coordinated by DWQ, NC Center for Geographic Information and Analysis
(CGIA) and DOT and based on the US Environmental Protection Agency's
Ecoregion Map (Griffith, G.E., et. al. 2002). If statistically valid data are collected,
then these data can be used to accurately predict the length of streams in a
particular watershed without extensive stream mapping in that watershed.
V. References
Castelle, A.J, et. al. 1994. Wetland and stream buffer requirements - A review.
Journal of Environmental Quality 23:878-882.
Doohaluk, D.A. 2000. A summary of the integration of science and policy: A case
study on riparian forest buffers. Master of Public Health report, Institute for Public
Affairs, University of South Carolina. Columbia, SC.
Griffith, G.E., et. al. 2002. Ecoregions of North and South Carolina. Reston, VA.
N.C. Division of Water Quality. 2005. Identification Methods for the Origins of
Intermittent and Perennial Streams. Version 3.1. Raleigh, NC
U.S. Army Corps of Engineers, U.S. Environmental Protection Agency, NC Wildlife
Resources Commission and NC Division of Water Quality. 2003. Stream Mitigation
Guidelines. Wilmington, NC.
Wenger, S. 1999. A review of the scientific literature on riparian buffer width, extent
and vegetation. Institute of Ecology, University of Georgia. Athens, GA.

Appendix 1
Preservation Demonstrable Threat Guidance Criteria
(Prepared for use by the NC EEP Program Assessment and Consistency Group -PACG)
April 5, 2004
Version 1.1
The 1995 Federal Guidance for the Establishment, Use and Operation of Mitigation Banks and Corps Mitigation
RGL 02-2 (12-26-02) have almost identical language concerning preservation and the demonstrable threat
requirement. Both documents state that the use of preservation as a sole basis for mitigation should only be under
exceptional circumstances and should meet the following requirements:
"Districts will consider whether the wetlands or other aquatic resources: 1) perform important physical, chemical or
biological functions, the preservation and maintenance of which is important to the region where those aquatic
resources are located; and, 2) are under demonstrable threat of loss or substantial degradation from human activities
that might not otherwise be avoided. The existence of a demonstrable threat will be based on clear evidence of
destructive land use changes that are consistent with local and regional (i.e., watershed) land use trends, and
that are not the consequence of actions under the permit applicant's control." (RGL 02-2)
These two guidance documents establish two conditions that must be met for "stand alone" preservation to be used
for mitigation credit. Stand alone preservation is defined as preservation not augmenting the functions of newly
established, restored or enhanced aquatic resources. The EEP Program Assessment and Consistency Group (PACG)
developed the Preservation Criteria Guidance to use for determining if preservation sites satisfy the first criteria, i.e.,
ecologically significant to the region. The following guidance is to be used to determine if the second criteria, i.e.,
"clear evidence of demonstrable threat" has been satisfied.
It is o8en difficult to document whether a "demonstrable threat" exists to an aquatic resource and the resource
agencies have not developed specific guidelines for making this determination. For this reason, the PACG has
prepared the following list of items to be considered when preparing the "clear evidence of a demonstrable threat of
loss or substantial degradation from human activities" documentation. When consulting this list, one should
consider what is reasonably foreseeable within the next ten years and realize there may be additional items which
should be considered for individual scenarios.
Demonstrable Threat Items*
^ Development trends in the watershed.
^ Nearby tracts being developed
^ Proximity of metropolitan areas
^ Water and/or sewer lines extension plans for the area
^ Local and DOT thoroughfare plans
^ Specific development plans for tract
^ Timbering threat to stream buffers
^ Local land trust (or other sources) of local information on potential development
^ Age of landowners in the area
^ Threats to listed species (if present)
^ Buffer protection rules in watershed, trout waters, etc.
^ Permitting issues -how likely to be permitted for fill activities (high quality wetlands, etc.)
^ To what extent is resource already protected by local/state/federal ordinances and regulations
*This list is not intended to be used as a checklist. The above are items to be considered when preparing the
demonstrable threat discussion for preservation sites for mitigation during the EEP transition phase.
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Appendix 2
Figure 1. Reduction of nitrate nitrogen as a function of riparian buffer width
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Width (feet)
Figure 2. Sediment reduction

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Width (feet)
Figure 3. Phosphorus reduction
60 70
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