HomeMy WebLinkAbout19960722 Ver 1_More Info Received_19991114t 10 i.
TBE JOHN K WADAMS COMP
LETTER OF TRANSMITTAL
To: Mr. John Dorney
NC Division of Water Quality
4401 Reedy Creek Road
Raleigh, NC 27607
Re: Eagle Ridge Stream Relocation
I am sending you the following item(s):
Date:
IVf A ?? i
U.'?aDS G* OUP
QUALITA'T l l
10-14-99
1?f?u? ?t C T VF' 1Z
Job No.: ACD-99000
COPIES DATE NO. DESCRIPTION
1 8/13/99 2 Detailed Planting plan for Eagle Ridge Stream Reloc.
1 10/14/99 5 Revised Stream Relocation Plans
1 10/13/99 1 Responses to Sept. 21, 1999, 401 Certification
1 10/1/99 1 Inadequate Buffer Delineation Exhibit
These are transmitted as checked below:
? As requested ? For your use
® For approval ?
? For review and comment ?
Remarks: Mr. Dorney, here is the revised set of construction plans for the Eagle Ridge Stream
Relocation (per DWQ's 9-21-99, 401 Certification). Also included is a letter of response to Conditions of
Certification numbers 5 & 7. An exhibit is included to display areas that are inadequately buffered as
referred to in the resDonse letter. Please call if you have anv auestions. Thanks.
Copy to: Brian Surak, P.E.
Signed:
I., S.S.I.T.
CIVIL ENGINEERING • LAND PLANNING • LANDSCAPE ARCHITECTURE • SURVEYING
PO Box 14005 • Research Triangle Park, NIC 27709 • (919) 361-5000 • fax (919) 361-2269
www.johnrmcadams.com
THE JOHN R. McADAMS COMPANY, INC.
October 13, 1999
Mr. John Dorney
North Carolina DENR
Raleigh Regional Office
Division of Water Quality
4401 Reedy Creek Road
Raleigh, NC 27607
Re: Eagle Ridge Stream Relocation
ACD-99000
WQC Project #960722
COE #199920576
Dear Mr. Dorney,
This letter is in response to your September 21, 1999 North Carolina 401 Water
Quality Certification for the Eagle Ridge Development and Golf Course. Several
Conditions of Certification were listed as part of the permit. This letter addresses
required amendments to the mitigation plan (condition #5) and areas of the
proposed stream relocation that are inadequately buffered along the railroad right-
of-way (condition #7).
Condition #5 states that: ,
A final detailed physical and biological monitoring plan for the stream r tn?'"`_
restoration shall be submitted for DWQ's written approval by November
15, 1999. This plan should include an amended mitigation plan (based
on your August 3, 1999 "Eagle Ridge Stream Relocation Plan")
depicting:
a) planting species and densities,
b) more detail for the "tie-in" to the natural channel
at the bottom of the reach,
c) the angle of the rootwad revetments, and
d) the "double-wing" deflectors changed to "single-
wing" deflectors or eliminated altogether.
CIVIL ENGINEERING • LAND PLANNING • LANDSCAPE ARCHITECTURE • SURVEYING
PO Box 14005 • Research Triangle Park, NC 27709 • (919) 361-5000 • fax(919)361-2269
www.johnrmcadams.com
THE JOHN R. McADAMS COMPANY, INC.
Mr. John Dorney
October 13, 1999
Page Two
The John R. McAdams Company is preparing the final mitigation plan, while the
he stream restoration is
final detailed physical elagi=?nsultant
being prepared by EnviroFor convenience, each
amendment to the milisted above.
A) In early July, M
r. Ken Jolly of the US Army Corps of Engineers was
contacted concerning suitable planting species and densities for the Eagle Ridge
site stream buffers. Mr. Jolly recommended speaking with Mr. Owen Anderson
of the NC Wildlife Resources Commission to obtain appropriate species and
spacing suggestions, since no written Corps of Engineers guidelines exist. After
talking with Mr. Owen Anderson, a detailed planting / landscaping plan (designed
by Mr. Shawn Anderson of Basnight Land & Lawn) for the stream relocation site
was submitted to DWQ (addressed to Mr. Todd St. John, P.E.) on August 16,
1999. This plan utilizes native, mass producing species recommended by Mr. ?w l I f
Owen Anderson. Mastproducing trees were recommended due to their benefits
to local wildlife versus simply planting live willow stakings. Mr. Owen Anderson
recommended that Mr. Shawn Anderson utilize spacings that he (Shawn) felt V ?v of
were appropriate for the selected species, since Shawn is highly experienced in M?? ) (19/1nP d
landscape design. The detailed planting plan, as submitted on August 16, 1999, Z
directly implements all of Mr. Owen Anderson's recommendations, and is more
than adequate to supply appropriate buffer materials due to the large size and type US
of trees selected.
B) More detail for the "tie-in" to the natural channel at the bottom of the reach is
supplied with an additional plan sheet. The additional plan sheet focuses on the
"tie-in" at a scale of 1"=10'. As this sheet displays, the existing channel
centerline makes approximately an 18-foot radius bend before continuing to the
next downstream bend. The proposed channel "tie-in" increases the bend radius
to approximately 27-feet; a 50% increase in bend radius as compared to the
existing stream centerline bend radius. By increasing its radius, this stream bend
will be more stable with the proposed channel in place than with existing
conditions.
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C) The details for the stream relocation plan have been updated to indicate that f , n G?1
rootwads are to be installed at an angle of 20 to 30 degrees from normal to the
face of the stream bank, with the base of the rootwad facing upstream. __I ?C
THE JOHN R. McADAMS COMPANY, INC.
Mr. John Dorney
October 13, 1999
Page Three
D) As a result of a telephone conversation with Mr. Eric Fleek of the NCDWQ,
all references to "double-wing" deflectors have been removed from the stream
relocation plan. Channel constrictors were viewed as more appropriate for a
stream of this size.
Condition #7 states that:
Contribution to the NC Wetland Restoration Program for the
inadequately buffered stream restoration shall be provided on the
enclosed form or a similar length of additional stream mitigation will be
needed. This area includes the fill authorized in our November 4, 1998
approval (316 feet), golf crossings as well as areas within the railroad
right-of-way, where a 50 foot wide wooded buffer cannot be assured. An
accounting of this length must be provided to DWQ by October 15, 1999
and payment received by November 15, 1999.
In order to calculate an equivalent length of inadequately buffered stream
requiring payment into the NC Wetland Restoration Program, measurements
indicating needed buffer area versus supplied buffer area, along with
corresponding channel lengths, were taken along stream sections where less than
50 feet of forested buffer is supplied. Since the developer cannot assure the long-
term maintenance of the existing forested vegetation within the railroad right-of-
way, this portion of the existing forested buffer was not counted in the
measurements. However, an average of 20 feet of canopy over the railroad right-
of-way, supplied by existing mature trees on the Eagle Ridge property, was
included in the measurements of supplied buffer, since the long-term maintenance
of these trees can be assured.
The average riparian buffer width in all areas that are less than 50 feet wide was
calculated using the measurements mentioned above. There are 6 areas along the
proposed stream where this occurs (analyzing each side of the stream separately).
Since the measured centerline lengths only represent one side of the channel, all
lengths were added and then divided by 2 in order to represent a true length of
inadequately buffered stream.
THE JOHN R McADAMS COMPANY, INC.
Mr. John Dorney
October 13, 1999
Page Four
Facing downstream, section A represents the left side of the stream from
approximately stakes 4 to 6. Section B represents the right side of the stream
from approximately stakes 3 to 10. Section C represents the left side of the
stream from approximately stakes 12 to 14. Section D represents the right side of
the stream from approximately stakes 20 to 24. Section E represents the left side
of the stream from approximately stakes 22 to 24. Section F represents the left
side of the stream from approxim y stakes 26 to 28.
17.1
Section A: L=85ft; Buffer Nee ed=5,530sf; Buffer Supplied=1,872sf
Section B: L=400ft; Buffer Needed=18,253sf; Buffer Supplied=10,887sf
Section C: L=65ft; Buffer Needed=4,972sf; Buffer Supplied=3,633sf
Section D: L=185ft; Buffer Needed=9,374sf; Buffer Supplied=7,775sf
Section E: L=70ft; Buffer Needed=4,997sf; Buffer Supplied=3,906sf
Section F: L=50ft; Buffer Needed=4,662sf; Buffer Supplied=3,063sf
Total Length=855ft Total Length / 2=427.5ft
Total Buffer Area Needed to Supply 50 ft width=47,788sf
Total Buffer Area Supplied According to Plans=31,136sf
.n
Average Buffer Width Where < 50ft Wide = 50ft x (31,136sf / 47,788sf) = 32.6ft
Equivalent Length of Stream That Needs To Be Paid for Due to Inadequate
Buffer Width
= [ 1 - (31,136sf / 47,788sf) ] x 427.5ft = 149ft
A plan delineating inadequately buffered stream lengths is included for your
reference. These calculations and measurements were performed to give a fair
accounting of inadequately buffered stream length. While 32.6 feet of buffer
width will not provide as much nutrient removal as a full 50 foot buffer would, it rx
removes considerably more nutrients than no buffer at all, therefore, its effects
should be accounted for. The calculations performed above represent this fact.
?655?
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THE JOHN R. McADAMS COMPANY, INC.
Mr. John Dorney
October 13, 1999
Page Five
If you have any questions or concerns about the responses to these conditions,
please do not hesitate to call.
Sincerely,
THE JOHN R. McADAMS COMPANY, INC.
Scott Mitchell, E.I., S.S.I.T.
Associate Project Engineer
C: Ken Jolly, US Army Corps of Engineers
Ken Bailey, Arland Community Development
Diana St. John, P.E., Arland Community Development
Melanie Connelly, P.E., Arland Community Development
Jim Spangler, Spangler Environmental Consultants
Brian Surak, P.E., The John R. McAdams Company, Inc.