HomeMy WebLinkAbout20140332 Ver 1_Revised Draft Mitigation Plan eApproval Letter_20151103 November 3, 2015
Regulatory Division
Re:NCIRT Review and USACE Approval of the Browns Summit Creek revised DraftMitigation Plan;
SAW-2014-01642; DMS Project#96313
Mr. Tim Baumgartner
North Carolina Division of Mitigation Services
1652 Mail Service Center
Raleigh, NC 27699-1652
Dear Mr. Baumgartner:
The purpose of this letter is to provide the North Carolina Division of Mitigation Services
(NCDMS) with all comments generated bythe North Carolina Interagency Review Team (NCIRT)
duringthe reviewperiod for the Browns Summit CreekMitigation Project. These comments are
attached foryour review.
Based on our review of these comments,includingthe provider’s response, and comments
generated during the revisedplanreview, we have determined that no major concerns have been
identified with the revised Draft Mitigation Plandated September 2015, which is considered approved
with this correspondence. However, severalminor issues were identified, as described in the attached
revised plan comment memo, whichmust be addressed in the Final Mitigation Plan.
The Final Mitigation Plan is to be submitted with the Preconstruction Notification (PCN)
Application for Nationwide permit approval of the project along with a copy of this letter. Issues
identified above must be addressed in the Final Mitigation Plan. All changes made to the Final
Mitigation Plan should be summarized in an errata sheet included at the beginning of the document. If it
is determined that the project doesnot require a Department of the Army permit, you must still provide a
copy of the Final Mitigation Plan, along with a copy of this letter, to the appropriate USACE field office
at least 30 days in advance of beginning construction of the project.Please note that this approval does
not preclude the inclusion of permit conditions in the permit authorization for the project, particularly if
issues mentioned above arenot satisfactorily addressed. Additionally, this letter provides initial approval
for the Mitigation Plan, but this does not guarantee that the project will generate the requested amount of
mitigation credit. As you are aware, unforeseen issues may arise during construction or monitoring of
the project thatmayrequire maintenance or reconstruction that may lead to reduced credit.
REPLY TO
ATTENTION OF:
DEPARTMENT OF THE ARMY
WILMINGTON DISTRICT, CORPS OF ENGINEERS
69 DARLINGTON AVENUE
WILMINGTON, NORTH CAROLINA 28403-1343
Thank you for yourprompt attention to this matter, and ifyou have any questions regarding this
letter, the mitigation plan review process,or the requirements of the Mitigation Rule, please call me at
919-846-2564.
Sincerely,
Andrea Hughes
Mitigation ProjectManager
Enclosures
Electronic Copies Furnished:
NCIRT Distribution List
Jeff Schaffer, NCDMS
HUGHES.ANDREA.W
ADE.1258339165
Digitally signed by
HUGHES.ANDREA.WADE.1258339165
DN: c=US, o=U.S. Government, ou=DoD, ou=PKI,
ou=USA, cn=HUGHES.ANDREA.WADE.1258339165
Date: 2015.11.03 09:22:35 -05'00'
DEPARTMENT OF THE ARMY
WILMINGTON DISTRICT, CORPS OF ENGINEERS
69 DARLINGTON AVENUE
WILMINGTON, NORTH CAROLINA 28403-1343
REPLY TO
ATTENTION OF:
CESAW-RG/Hughes October 19, 2015
MEMORANDUM FOR RECORD
SUBJECT: Brown’s Summit Creek - NCIRT Comments/Revised Mitigation Plan Review
PURPOSE: The comments listed below were received in response to the revised Mitigation Plan
dated September 2015.
NCDMS Project Name: Browns Summit Creek Mitigation Project, Guilford County, NC
USACE AID#: SAW-2014-01642
NCDMS #: 96313
Initial Comment Deadline: 15 July 2015
Revised Mitigation Plan Posted to Portal: 21 September 2015
Ginny Baker, NCDWR, 15 October, 2015:
1.Response acceptable.
2.Response acceptable.
3.Response acceptable. Correction - NCDWR will require 30 days of consecutive baseflow
for monitoring wells installed in T1 and T3 during a normal rainfall year (not a during
normal growing season).
4.NCDWR found the detailed description and calculations of the proposed BMPs for R6
and T4 to provide the needed information required to better understand the design and
function of the BMPs.
5.The BMPs are proposed to generate a 1.5:1 credit ratio as was agreed to in the field.
Since these BMPs are credit generating assets a success standard is required, as it is for
all other credit generating assets at mitigations sites, even if this issue was not
specifically discussed during field visits. Please consider that it is not possible to review
every aspect of a proposed mitigation plan during the field visit which is why the
request for more information in regards to a success standard was made during the
draft plan review process. NCDWR recommends the following additions to the draft
mitigation plan.
a.The step-pool channels (R6 outlet and T4) will be considered successful if stability
has been attained as agreed upon by the IRT at closeout.
b.Constructed Wetland (R6) – Vegetation should be monitored yearly to determine
the percent coverage of the constructed wetland. A success standard of 70 percent
of native vegetation as defined in the NCDWR BMP manual (page 9-21 of the
NCDWR BMP manual) will be required. This should be a visual estimate of overall
coverage of the pool area, native volunteers can be included. The plot in the buffer
area of the BMP with planted stems should have the same standard success criteria
as other veg plots. All yearly maintenance and repairs, photopoints, replantings, and
invasive treatments will be documented in the monitoring reports. Sediment build-
up should be minimal and not require repeated maintenance at closeout as agreed
upon by the IRT for the constructed wetland to be considered successful.
c.NCDWR BMP field inspection - One field visit by NCDWR should be conducted
between years 2-5 to inspect the BMPs. It will be up to Baker to schedule this.
Annual monitoring may be requested by Baker instead of bi-annual monitoring for
the BMPs after five years until closeout if the stormwater control measure
structures are stable and have not required maintenance in the past year.
d.In Section 9.0 Performance Standards: Success criteria for the BMPs should be
added since they are not included in any of the referenced documents.
e.In Table 10.1 Monitoring Requirements: Change the frequency of stormwater BMP
inspections to semi-annually to be consistent with the earlier text.
Andrea Hughes, USACE, 19 October, 2015:
1.Response acceptable.
2.Response acceptable.
3.According to the Technical Proposal, the Browns Summit Creek Mitigation Project is
subject to applicable guidance associated with RFP 16-005568 (Monitoring
Requirements and Performance Standards for Stream and/or Wetland Mitigation dated
November 7, 2011). The performance standards in the guidance document provide
height requirements for planted vegetation.
4.Response acceptable.
5.See NCDWR #5 response above. The Corps concurs with NCDWR comments regarding
monitoring protocols and performance standards for the proposed BMPs.
6.Response acceptable.
7.Recommend groundwater hydrology data collection on a 12 month basis as opposed to
monitoring only during the growing season.
8.We do not anticipate a need for long-term management of the proposed BMP
structures provided they remain stable and functioning throughout the 7-year
monitoring period. In the event the BMPs fail to meet the standards noted above
(NCDWR #5 response), mitigation credits may be adjusted accordingly.
9.Response acceptable.
Andrea Hughes
Mitigation Project Manager
Regulatory Division
HUGHES.ANDREA.
WADE.1258339165
Digitally signed by
HUGHES.ANDREA.WADE.1258339165
DN: c=US, o=U.S. Government, ou=DoD,
ou=PKI, ou=USA,
cn=HUGHES.ANDREA.WADE.1258339165
Date: 2015.10.19 12:03:49 -04'00'
DEPARTMENT OF THE ARMY
WILMINGTON DISTRICT, CORPS OF ENGINEERS
69 DARLINGTON AVENUE
WILMINGTON, NORTH CAROLINA 28403-1343
REPLY TO
ATTENTION OF:
CESAW-RG/Hughes July 29, 2015
MEMORANDUM FOR RECORD
SUBJECT: Browns Summit Creek Mitigation Project - NCIRT Comments During 30-day Mitigation
Plan Review
PURPOSE: The comments listed below were posted to the NCDMS Mitigation Plan Review
Portal during the 30-day comment period in accordance with Section 332.8(g) of the 2008
Mitigation Rule.
NCDMS Project Name: Browns Summit Creek Mitigation Project, Guilford County, NC
USACE AID#: SAW-2014-01642
NCDMS #: 96313
30-Day Comment Deadline: 16 July 2015
Todd Bowers, USEPA, July 14, 2015:
1.Table 1; Page 2-1: R1 Drainage area is listed as 438 acres. This is not consistent with
other values such as Table 4.1 (448 acres)
2.Page 1-2: Recommend adding “restore stream and floodplain connectivity” in list of
bulleted primary goals especially since wetland hydrology performances are depending
on it.
3.Page 1-2: Stated objectives should be measurable (as well as specific, attainable,
reasonable and trackable). Improvement, as well as degradation, in water quality is
measurable. If this is the case then Baker should be measuring water quality for at least
some parameter to demonstrate that this objective has been achieved. Performance
standards relating to water quality, especially if tied to the BMPs (R6 and T4), should be
developed accordingly.
4.Page 2-2; last paragraph: R2 and R1 are not second-order streams, especially if R3 and
R4 are considered first-order. The inclusion of T-2 (zero order) does not change the
stream order of the main stem.
5.2.2.1; Page 2-3 first paragraph: Land use percentages of the “watershed” are not
consistent with those listed on Page 1-1 and Table 4.1. The “watershed” in question
changes from an 83-square mile HUC to the project watershed with differing
percentages in one comparison and same percentages in another comparison.
Recommend making this clearer in the document.
6.4.0 Baseline information: Some water quality parameter(s) should be included in order
to demonstrate that 1) the water quality is impaired and needs improvement and 2)
that improvements to water quality, a stated objective, has been achieved. Fecal
coliform or E. coli might be a suitable parameter in this case since we are dealing with
cattle exclusion.
7.Table 4.1: Project Drainage Area does not match R1 Drainage Area and 2.2.1
8.Table 4.1: Missing 7 percent of land use classification?
9.Table 5.1: BMP Elements. Both Elements state that improvement in water quality is part
of the Purpose/Function. How do we know that this will be achieved successfully?
10.7.1.3, Page 7-2: Live stake density appears erroneous. “40 stakes per 1,000 square feet”
should read “400 stakes per 1,000 linear feet” This will achieve the spacing required.
11.Page 7-5, last paragraph: “Reducing streambank sediment loading and removing cattle
will provide ecological uplift by improving water quality…” Once again a water quality
objective is stated with no baseline data or plans to collect data to support this
statement. Recommend collecting baseline water quality data to provide evidence that
ecological lift has (or has not) been achieved. The statement in the following paragraph
does provide for removing the inputs via cattle exclusion but that does not present
measurable data that water quality itself is better and if so by how much.
12.9.0, Page 9-1 and 9.2, Page 9-3: No performance standard is given for tree heights at 5
years (7’) and 7 years (10’). Recommend adding this performance standard unless Baker
can justify why this cannot be achieved.
13. 9.2, Page 9-3: First paragraph mentions R7. Remove R7
14.9.2, Page 9-3: Vegetation monitoring addresses riparian buffer monitoring and plot
density. It is unclear how wetland vegetation monitoring will be conducted. Recommend
at least one plot per wetland type/area in addition to monitoring riparian buffer
vegetation.
15.17.1.1.1, Page 17-1: R3 and R2 drainage areas do not match Table 1 in Site Selection
16.Tables 17-7 and 17-8: Design Estimates and Proposed Bankfull Velocities for R1, R2, R3
and R4 do not match.
17.17.5.1, Page 17-46: Are three automated groundwater wells enough coverage for
monitoring five wetland types? It appears that six stations are going to be installed per
Figure 9.1 on page 9-6
18.17.7.2, Page 17-51: Live stake density appea rs erroneous. “40 stakes per 1,000 square
feet” should read “400 stakes per 1,000 linear feet” This will achieve the spacing
required.
19.Tables 17.10 -12: Planting plan appears excellent for both riparian buffer and wetlands.
Ginny Baker, DWR, 1 June 2015:
1.Monitoring wells should be installed along intermittent reaches that are proposed for
priority 1 restoration to ensure a minimum of 30 consecutive days of base flow is
maintained during a normal growing season. One well should be installed in the upper
part of the reach for R4 (in the intermittent section if this overlaps with P1 restoration),
reach T1 and reach T3.
2.The hydrology success criteria proposed for wetlands located in the lower end of the
project along reaches 1 and 2 are inconsistent. The 12% success standard for a normal
precipitation year proposed for the wetland type 2 (degraded) and wetland type 3
(partially functioning) seems appropriate for a riverine/riparian associated wetland.. The
6% hydrology success standard proposed just upstream for wetland type 4 (filled),
which is the same type of wetland, does not seem appropriate, especially as a 1:1 credit
ratio is proposed. In addition, a 9% hydrology standard (which NC DWR finds acceptable
for a headwater wetland associated with a first order stream) is proposed further
upstream closer to the headwaters along Reach 4 in wetland type 5 (filled). NC DWR
understands Baker is concerned that only removing fill and using the E1 approach rather
than P1 restoration which would raise the channel and increase flooding may not result
in the same level of hydrological uplift as along Reach 1 where P1 restoration is
proposed. Perhaps the 1:1 ratio should be adjusted if only a partial hydrological uplift
for wetland type 3 is achieved.
3.Please add a vegetation plot to Wetland type 5, which is already established with
mature successional species.
4.NC DWR would like more design specifications to be provided in the final mitigation plan
for the two proposed BMPs. For the Constructed Wetlands, reference has been made
to the BMP manual. The plans should clearly identify all key elements of the design with
regards to requirements in either the BMP manual or the new MDC for Constructed
Wetlands with explanations for any deviations from the typical design requirements.
The BMP Supplement Form may provide guidance for what details to provide in future
design documents. Regenerative Stormwater Conveyances (RSCs) as proposed for T4 on
Table 7.1, page 7-4, are not in the NC BMP Manual so it is unclear what design standard
will be used for the RSC NC DWR would recommend that RSC designs adhere to the
Anne Arundel County, MD or the West Virginia design standards for RSCs, available at
http://www.aacounty.org/DPW/Watershed/StepPoolStormConveyance.cfm and/or
http://www.dep.wv.gov/WWE/Programs/stormwater/MS4/Documents/Specification_4.
2.7_Regenerative_Stormwater_Conveyance_WV-SW-Manual-11-2012.pdf.
5.The BMP success standards and objectives for R6 and T4 need further description in
Section 9.4. Please describe what performance standards will be used to document that
the BMPs are providing functional uplift to the mitigation project.
6.How will the two BMPs be maintained in perpetuity after the site is closed out?
Andrea Hughes, USACE, 26 July 2015:
1.Section 2.2: The mitigation plan indicates that another category of wetlands has been
added to the plan during mitigation plan development. During mitigation plan
development, the Corps made numerous visits to the Brown’s Summit site and held
several discussions regarding changes to the mitigation plan associated with proposed
mitigation activities and determination of mitigation credits. The intent of on-site
meetings and discussions is to resolve concerns or issues associated with the mitigation
proposal prior to submitting the draft mitigation plan. At no time during the course of
these meetings was the proposal to add another category of wetlands to the mitigation
plan in order to generate additional credits discussed with the Corps and/or the IRT.
Please remove from the mitigation plan those areas located adjacent to Reach 4 and
identified as “5-Hydrologic Reestablishment, 1:1 credit ratio” on Figure 9.1. No
mitigation credits will be generated for these areas.
2.Section 8.1: Regarding the proposed BMPs, Table 8.1: Routine Maintenance
Components states that the stormwater management devices will be monitored and
maintained per the protocols and procedures defined by the NCDWR Stormwater BMP
Manual (BMP manual). Please list the routine maintenance activities as specified in the
BMP manual or reference the page number/table from the manual that lists the specific
maintenance activities that will be performed. The frequency of maintenance
inspections should be consistent with the BMP manual.
3.Section 9.2: The NCDMS Monitoring Requirements and Performance Standards for
Stream and/or Wetland Mitigation dated November 7, 2011 stipulates that planted
vegetation must average 10 feet in height in each plot at year 7. Please include this
requirement in the vegetation performance standards.
4.Section 9.3.2 Wetland Hydrology: The mitigation plan states that performance
standards for wetland hydrology will follow a range from 6-12%, depending on the
specific wetland location and the mitigation activity proposed. Wetland areas receiving
credit for restoring or enhancing wetland hydrology should demonstrate saturation
within 12 inches of the soil surface for a minimum 8.5% of the growing season for
Guilford County.
5.Section 9.0: Please provide performance standards for the constructed wetland (R6) and
the regenerative stormwater control device (T4). In addition, please provide
appropriate monitoring protocols that demonstrate compliance with the proposed
performance standards.
6.Section 10.0: Post-construction profile data should be provided for the entire length of
all Restoration/ Enhancement I stream components.
7.Section 10.0: The Table 1: Monitoring Requirements chart should include a section for
wetland hydrology monitoring requirements.
8.Section 11.0: The Long-Term Management Plan should include a list of long-term
management activities required for site sustainability, the party responsible for
conducting these activities, and details regarding the funding of these activities.
According to the BMP manual, BMPs require routine inspections on at least a quarterly
basis and after each large storm event. Please provide additional information regarding
the annual costs associated with BMP maintenance and repair; funding for maintenance
and repair activities, and the party responsible for these activities. If the conservation
easement holder will assume responsibility for these annual maintenance activities and
any associated emergency maintenance and repair costs, please provide written
confirmation from the conservation easement holder. For those areas where no long-
term management activities are anticipated (stream and wetland
restoration/enhancement), please include a statement to this effect in the mitigation
plan along with an explanation.
9.Temporary and permanent impacts to existing wetlands and streams must be accounted
for in the PCN and the loss or conversion of those waters must be replaced on-site.
Please include a map depicting the location of all impacts with the PCN.
Andrea Hughes
Mitigation Project Manager
Regulatory Division
HUGHES.ANDREA.
WADE.1258339165
Digitally signed by
HUGHES.ANDREA.WADE.1258339165
DN: c=US, o=U.S. Government, ou=DoD, ou=PKI,
ou=USA, cn=HUGHES.ANDREA.WADE.1258339165
Date: 2015.07.29 16:42:33 -04'00'