20151118 Ver 1_Riparian Buffer Authorization_20151026

34 Castlewood Drive
Clayton, NC 27520
(919) 624 -8825
October 21, 2015
NCDWR — 401 & Buffer Permitting Unit
1617 Mail Service Center
Raleigh, NC 27699.1 617
2 °951
1 18
Re; Riparian Buffer Authorization Request for a Level Spreader Bypass Channel and
Temporary Erosion Control ;Matting into an Unnamed Tributary to Mark's Creek
Rivenvood Athletic Club — ,Alpine Valley Phase 6D1
PIN #: 176000-99-7610,176000.!89-7514, 176000 -89 -6113
Dear Sir/Madam:
Please find enclosed an After- the -fact Riparian Buffer Authorization Request, a copy of the
written response letter from DC Adams Engineering to the Division of Water Resources
regarding an on -site inspection of the site, a retrofit design for a modified land quality level
spreader with splitter box and high -flow bypass channel, soil map, and USGS topographical map.
The level spreader with a splitter box and bypass channel was constructed and installed in July,
20 15 to address concerns of concentrated flow into an unnamed tributary to Mark's Creek. The
area was inspection on October 16, 2015 and it was noted that the retrofit level spreader appears
to be working as designed for the 1 hAir storm event. All stormwater flows that exceed the
expected peak flow from the I in/hr storm event discharges through the buffer in the bypass
channel.
If any additional information is needed. please advise.
Sincerely.
Jamie Guerrero, PE, CPSWQ
PNTA Environmental Consultants
OCT Q:5 L;g 0 W [2 0
2 c zoos
DENR - WATER RESOURCES
401 & BUFFER PERMITTING

Pictures from October 16, 2015
Existing stormwater outfall ditch lined with riprap located up -stream of the riparian buffer.
Land quality style level spreader. View point is from the splitter boa facing the retrofit level
spreader.

Bypass Channel. View point is from the splitter box looking at the bypass channel toward the
unnamed tributary. The low -flow level spreader is to the left of the picture.
Low flow level spreader with inlet pipe from splitter box shown. The bypass channel is shown at
the top of the picture. The splitter boa manhole lid is barely visible at the top of the picture next
to the corner of the privacy fence.

I,
State of North Carolina
D,W-
,R Department of Environment and Natural Resources
Division of Water Resources Division of Water Resources
15A NCAC 02B.0233 (8)(b), .0243 (8)(b), .0250 (11)(b), .0259 (8)(b),.0267 (11)(c), .0607 (e)(2) — Buffer Authorization
FORM: BA 10 -2013
Riparian Buffer Authorization Form
A. Applicant Information
1. Project Information
1a. Name of project: Riverwood Athletic Club — Alpine Valley Phase 6D1
1 b. County: Johnston
1c. Nearest municipality: Clayton
ld Subdivision name: Alpine Valley Phase 6D1
1e. Is the project located in any of North Carolina's ❑ Yes ® No
twenty coastal counties. If yes, answer 1f below.
1f. Is the project located within a NC Division of Coastal ❑ Yes ® No
Management Area of Environmental Concern (AEC)?
2. Owner Information
2a. Name on Recorded Deed-
Riverwood on the Neuse, LLC; Simmental Ventures, LLC
2b Deed Book and Page No.
BK 3988 PG 0150
2c. Map Book and Page No.
BK 79 PG 164
(include a copy of the recorded
Donnie Adams, PE
map that indicates when the lot
Business name
was created):
DC Adams Engineering, Inc.
2d. Responsible Party
Riverwood on the Neuse, LLC; Simmental Ventures, LLC
(for Corporations):
2e. Street address:
400 Riverwood Drive
2f. City, state, zip:
Clayton, NC 27527
2g. Telephone no.: (919) 763 -7278
2h. Fax no.:
2i. Email address -
3. Applicant Information (if different from owner)
3a.
Applicant is.
® Agent ❑ Other, specify:
3b.
Name:
Donnie Adams, PE
3c
Business name
DC Adams Engineering, Inc.
(if applicable):
3d.
Street address.
335 Athletic Club Blvd
3e
City, state, zip:
Clayton, NC 27527
3f.
Telephone no -
919 - 763 -7278
3g.
Fax no.:
3h.
Email address:
[e-mail]
-- I
A
�II
— I
FORM: BA 10 -2013 Page 1 of 6

Section A. Applicant Information, continued
4. Agent/Consultant Information (if applicable)
4a. Name: Jamie Guerrero, PE
4b. Business name I PNTA Environmental Consultants
34 Castlewood Driive
Clayton, NC 27520
919- 624 -8825
pntaengineer @gmail.com
FORM: SSGP3080 8 -13 Page 2 of 6
(if applicable):
4c.
Street address:
4d.
City, state, zip:
4e.
Telephone no.:
4f.
Fax no.:
4g.
Email address:
34 Castlewood Driive
Clayton, NC 27520
919- 624 -8825
pntaengineer @gmail.com
FORM: SSGP3080 8 -13 Page 2 of 6

B. Project Information and Prior Project History
1.
Property Identification
1a.
Property identification no. (tax PIN or parcel ID):
1 176000 -99 -7610, 176000 -89 -7154, 176000 -89 -6113
1 b.
Site coordinates (in decimal degrees):
I Latitude: 35.69759 Longitude: - 78.43112
1 c.
Property size:
I acres
2.
Surface Waters
2a.
Name of nearest body of water to proposed project:
I UT to Mark's Creek
2b.
Water Quality Classification of nearest receiving
I C, NSW
water:
2c.
River basin:
I Neuse
3.
Project Description
3a.
Describe the existing conditions on the site and the general
land use in the vicinity of the project at the time of
this application:
Residential subdivision
3b. Attach an 8'/ x 11 excerpt from the most recent version of the USGS topographic map indicating the location
of the site J
3c. Attach an 8'h x 11 excerpt from the most recent version of the published County NRCS Soil Survey Map
depicting the project site J
3d. List the total estimated linear feet of all existing streams (intermittent and perennial) on the property:
3e. Explain the purpose of the proposed project:
Retrofit of an existing stormwater outfall with a level spreader / splitter box with bypass channel in order to
provide diffuse flow through the buffer.
3f. Describe the overall project in detail, including the type of equipment to be used:
Construction of level spreader with bypass channel and installation of geotextile liner using light construction
equipment and manual labor.
4. Jurisdictional Determinations J
4a. Have jurisdictional wetland or stream determinations by the ® Yes ❑ No ❑ Unknown
Corps or State been requested or obtained for this property/ Comments:
project (including all prior phases) in the past?
4b. If yes, who delineated the jurisdictional areas? Agency/ Consultant Company: Soil &
Name (if known): Environmental Consultants
Other:
4c. If yes, list the dates of the Corps jurisdictional determinations or State determinations and attach
documentation.
5. Project History
5a. Have permits or certifications been requested or obtained for ® Yes ❑ No ❑ Unknown
this project (including all prior phases) in the past? J
5b. If yes, explain and detail according to "help file" instructions.
This project is a phase of the Riverwood Athletic Club development which has 401 and 404 permits. JI
6. Future Project Plans
6a. Is this a phased project? ® Yes ❑ No
6b. If yes, explain.
This is a phased planned unit development with multiple phases.
FORM: BA 10 -2013 Page 3 of 6

C. Proposed Impacts Inventory
1. Buffer Impacts
1a. Project is in which protected
❑ Neuse
❑ Tar - Pamlico ❑ Catawba
basin?
❑ Randleman
❑ Jordan ❑ Goose Creek
1 b. Individually list all buffer impacts below. If any impacts require
mitigation, then you MUST fill out Section D of
this form.
Buffer impact Reason for
Type of impact
Stream name Buffer Zone 1 Zone 2
number — impact
(exempt, allowable,
mitigation impact impact
Permanent P
(
allowable w/
)
re q
q uired? (sq ft) (sq ft)
or Temporary
mitigation)
(T)
B1 ® P ❑ T Bypass channel
Allowable
UT to Mark's
❑ Yes ® No
200 130
Creek
B2 ❑ P ® T
❑ Yes ❑ No 180 316
B3 ❑P ❑T
❑ Yes ❑No�
B4 ❑ P ❑ T I
I ❑ Yes ❑ No
B5 ❑ P ❑ T
❑ Yes ❑ No
B6 ❑ P ❑ T
❑ Yes ❑ No
Total buffer impacts 380 446
1 c. Comments: Area 131 is for a level spreader bypass channel installed on a retrofit level spreader constructed in
order to mitigate erosion concerns in the riparian buffer.
D. Impact Justification and Mitigation
1. Avoidance and Minimization
1a. Specifically describe measures taken to avoid or minimize the proposed impacts in designing project.
This is an after - the -fact buffer authorization request for a bypass channel and temporary liner in the riparian
buffer in order to prevent further erosion from occurring in the buffer due to concentrated stormwater runoff.
1 b. Specifically describe measures taken to avoid or minimize the proposed impacts through construction
techniques. No large trees will be required to be removed.
FORM: BA 10 -2013 Page 4 of 6

E. Diffuse Flow Plan
All buffer impacts and high ground impacts require diffuse flow or other form of ® Diffuse flow
stormwater treatment. Include a plan that fully documents how diffuse flow will be ❑ Other BMP
maintained. If a Level Spreader is proposed, attach a Level Spreader Supplement Form.
If due to site constraints, a BMP other than a level spreader is proposed, please provide a
plan for stormwater treatment as outlined in Chapter 8 of the NC Stormwater BMP
Manual and attach a BMP Supplement Form.
F. Supplementary Information
1. Environmental Documentation
1 a. Does the project involve an expenditure of public (federal /state /local) funds or the use ❑ Yes ® No
of public (federal /state) land?
1 b. If you answered "yes" to the above, does the project require preparation of an ❑ Yes ❑ No
environmental document pursuant to the requirements of the National or State (North
Carolina) Environmental Policy Act (NEPA/SEPA)?
1c. If you answered "yes" to the above, has the document been finalized by the State ❑ Yes ❑ No
Clearing House? (If so, attach a copy of the NEPA or SEPA final approval letter.)
Comments:
2. Violations
2a. Is the site in violation of DWR Wetland Rules (15A NCAC 02H .0500), Isolated Wetland ❑ Yes ❑ No
Rules (15A NCAC 02H .1300), DWR Surface Water or Wetland Standards, or Riparian
Buffer Rules (15A NCAC 02B .0200)?
2b. Is this an after - the -fact permit application?
® Yes ❑ No
2c. If you answered "yes" to one or both of the above questions, provide an explanation of the violation(s):
_6,u ✓A v G AA, --, o, s J"I L- c C<Zz
Applicant/Agent's Printed Name Applicant /Agent's Signature Date
(Agent's signature is valid only if an authorization letter from the applicant is provided )
Send 3 complete sets of this form and accompanying documents to the following:
For government transportation projects sent
by First Class Nail via the US Postal Service:
NC DWR, Transportation Permitting Unit
1617 Mail Service Center
Raleigh, NC 27699 - 1617
For all other projects sent by First Class Mail
via the US Postal Service
Karen Higgins
NCDWR — 401 & Buffer Permitting Unit
1617 Mall Service Center
Raleigh, NC 27699 - 1617
For government transportation projects sent
by delivery service ((JPS, FedEx, etc.).
OR NC DWR, Transportation Permitting Unit
512 N. Salisbury Street
Raleigh, NC 27604
For all of /ter projects sent by delivery service
(UPS, FedEx, etc):
OR Karen Higgins
NCDWR — 401 & Buffer Permitting Unit
512 N. Salisbury Street
Raleigh, NC 27604
FORM: BA 10 -2013 Page 6 of 6

Riverwood Subdivision
Alpine Valley
Clayton, North Carolina
PNTA Environmental
Consultants
34 Castlewood Drive
Clayton, NC 27520
(919) 624 -8825
Soil Survey of Johnston County,
North Carolina
Issued: October 1994
Property Info.
Simmental Ventures, LLC
NC Pin# 176000 -99 -7610
Riverwood Subdivision
Bradshaw Way
Clayton, NC 27529

e
A
Riverwood Subdivision
Alpine Valley
Clayton, North Carolina
PNTA Environmental
Consultants
34 Castlewood Drive
Clayton, NC 27520
(919) 624 -8825
i
I�
l ?I
USGS Topographic Map
Clayton Quadrangle
7.5 Minute Series
1\
Property Info:
Simmental Ventures, LLC
NC Pin# 176000 -99 -7610
Riverwood Subdivision
Bradshaw Way
Clayton, NC 27529

k�i ./`� °� �'� �� ^�
- —� - - -
r
ENGINEERING, 1Nr,
June 22, 2015
Danny Smith
NC DENR -D WR
3800 Barrett Drive
Raleigh, NC 27699
Subject: Response to Site Visit in Riverwood Athletic Club
Alpine Valley Phase 6D 1
Johnston County
Dear Mr. Smith,
This letter is provided as written response to our onsite meeting in May 2015 at Riverwood Athletic —
Alpine Valley Phase 6D1 (Bradshaw Dr). Per discussion and recommendations from our onsite meeting
the following actions have been taken:
1. Area around the outfall swale between lots 6137/6138:
a. During the meeting it was determined that the current method to provide diffuse flow at the
end of this Swale was not working properly. Recommendations were made to provide an
alternate design. Attached please find a design for a splitter box, level spreader and bypass
channel.
b. The developer plans to mobilize immediately to begin repair /installation in this area
according to the attached design. Unless I hear otherwise from you or your office, work
according to the attached plan will begin within 2 weeks from the date of this letter.
c. Also, during the meeting it was noted that the erosion control measures at the intersection
of Bradshaw and Tarkenton needed maintenance. The developer moved immediately to
make sure the measures were maintained. See attached pictures.
d. A small amount of sediment was noted in the stream adjacent to this site. The developer
has contracted Angler Environmental to assist with, and ensure remediation efforts are
completed in a satisfactory manner. Angler Environmental is on standby for cleanup until
the repairs noted in l.e above have been completed.
2. Area at end of Bradshaw Way:
a. Per our onsite meeting, it was noted that the temporary sediment basin is properly located
and will serve as a sediment control measure until development is completed in this area.
Although, the basin is operating properly concentrated flow from large storm events
(greater than the 1" storm) is having an effect in the buffer area. As discussed on site, the
developer will install a temporary geotextile liner as a temporary bypass channel. This
work will be conducted at the same time as the work in Le. above. (to begin within 2
weeks from the date of this letter).
DC ADAMS ENGINEERING, INC s 335 Athletic Club Blvd, Clayton, NC 27527 e Office: 919 - 763 -7278 • Firm License # C -3894

b. Although the above noted measures will protect the buffer during continued construction,
design of a permanent plan that meets the diffuse flow requirements will be incorporated
into the design of the future extension of Bradshaw Way. This extension is planned for
2016.
c. The developer will work closely with the Johnston County Stormwater Administrator as
well as DWR to provide an appropriate design. I plan to submit the first review set for this
design around the end of 2015 or early 2016.
Pictures:
If you have any questions or commen%,P1ggA Dive me a call at 919 - 763 -7278 or
email to donnie @dcadamspe.com . CAR
Sincerely,
_ SEAL
2:469 �
Donald C. Adams, Jr, PE F ? 6/2Z/201 '
S,li1J`f /f1N11111155H�t0�� , `,

1 IN /HR STORM EVENT
SWAN TRAIL LEVEL SPREADERSP_1 Rainfall Duration =60 min, Inten =1.00 in /hr
Prepared by Microsoft Printed 6/9/2015
HydroCADO 10.00 s/n 05088 © 2011 HydroCAD Software Solutions LLC Page 1
Time span =0.00 -3.00 hrs, dt =0.01 hrs, 301 points
Runoff by Rational method, Rise /Fall= 1.0/1.0 xTc
Reach routing by Stor- Ind +Trans method - Pond routing by Stor -Ind method
Pond 6P: MH -1 Peak Elev= 199.81' Inflow =1.17 cfs 0.097 of
Primary=1.17 cfs 0.096 of Secondary=0.01 cfs 0.000 of Outflow =1.17 cfs 0.097 of

1 IN /HR STORM EVENT
SWAN TRAIL LEVEL SPREADERSP_1 Rainfall Duration =60 min, Inten =9.00 in /hr
Prepared by Microsoft Printed 6/9/2015
HydroCADO 10.00 s/n 05088 © 2011 HvdroCAD Software Solutions LLC Pacie 2
Summary for Pond 6P: MHA
[57] Hint: Peaked at 199.81' (Flood elevation advised)
Inflow Area = 3.750 ac, 0.00% Impervious, Inflow Depth = 0.31"
Inflow =
1.17 cfs @
0.09 hrs,
Volume=
0.097 of
Outflow =
1.17 cfs @
0.09 hrs,
Volume=
0.097 af, Atten= 0% Lag= 0.0 min
Primary =
1.17 cfs @
0.09 hrs,
Volume=
0.096 of
Secondary=
0.01 cfs @
0.09 hrs,
Volume=
0.000 of
Routing by Stor -Ind method, Time Span= 0.00 -3.00 hrs, dt= 0.01 hrs
Peak Elev= 199.81'@ 0.09 hrs
Device Routing Invert Outlet Devices
#1 Primary 196.80' 4.6" Round Culvert L= 7.0' RCP, groove end projecting, Ke= 0.200
Inlet/ Outlet Invert= 196.80'/ 196.50' S=0.0429'/' Cc= 0.900
n=0.010 PVC, smooth interior, Flow Area= 0.12 sf
#2 Secondary 199.80' 24.0" Round Culvert L= 20.0' RCP, groove end projecting, Ke= 0.200
Inlet/ Outlet Invert= 199.80'/ 197.00' S=0.1400'/' Cc= 0.900
n= 0.012 Concrete pipe, finished, Flow Area= 3.14 sf
Primary OutFlowMax =1.17 cfs@ 0.09 hrs HW= 199.81' (Free Discharge)
L1= Culvert (Inlet Controls 1.17 cfs @ 10.11 fps)
Secondary OutFlowMax =0.00 cfs @ 0.09 hrs HW= 199.81' (Free Discharge)
L2= Culvert (Inlet Controls 0.00 cfs @ 0.49 fps)
3
0
Pond 6P: MH -1
Hydrograph
.._.,.
1 4 4-7 -9-
if9
0.01 cfs
0 -4
Inflow Area =3.750 ac
Peak Elev= 199.81'
0 1 2 3
Time (hours)
■ Inflow
�_ ] Outflow
❑ Primary
❑ Secondary

10 -YR, 24 -HR STORM EVENT
SWAN TRAIL LEVEL SPREADER Q10_3 Rainfall Duration =60 min, Inten =5.88 in /hr
Prepared by Microsoft Printed 6/9/2015
HydroCADO 10.00 s/n 05088 © 2011 HydroCAD Software Solutions LLC Paae 1
Time span =0.00 -3.00 hrs, dt =0.01 hrs, 301 points
Runoff by Rational method, Rise /Fall= 1.0/1.0 xTc
Reach routing by Stor- Ind +Trans method - Pond routing by Stor -Ind method
Subcatchment2S: DA -1 Runoff Area =3.750 ac 0.00% Impervious Runoff Depth= 1.82"
Tc =11.9 min C =0.31 Runoff =6.89 cfs 0.570 of
Pond 6P: MH -1 Peak Elev= 200.70' Inflow =6.89 cfs 0.570 of
Primary=1.34 cfs 0.127 of Secondary=5.55 cfs 0.443 of Outflow =6.89 cfs 0.570 of
Total Runoff Area = 3.750 ac Runoff Volume = 0.570 of Average Runoff Depth = 1.82"
100.00% Pervious =3.750 ac 0.00% Impervious = 0.000 ac

10 -YR, 24 -HR STORM EVENT
SWAN TRAIL LEVEL SPREADER Q10_3 Rainfall Duration =60 min, lnten =5.88 in /hr
Prepared by Microsoft Printed 6/9/2015
HydroCAD® 10.00 s/n 05088 © 2011 HydroCAD Software Solutions LLC Paae 2
Summary for Subcatchment 2S: DA -1
Runoff = 6.89 cfs @ 0.20 hrs, Volume= 0.570 af, Depth= 1.82"
Runoff by Rational method, Rise /Fall= 1.0/1.0 xTc, Time Span= 0.00 -3.00 hrs, dt= 0.01 hrs
Rainfall Duration =60 min, Inten =5.88 in /hr
Area (ac) C Description
3.750 0.31
3.750 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
11.9 Direct Entry,
3
0
M
6_
5.
4=
3=
2_
1:
0=
0
i1
Subcatchment 2S: DA -1
Hydrograph
Rainfall
Duration =60 min,
Inten =5.88 in /hr
Runoff Area =3.750 ac
- ------- - - - - --
Runoff Volume =0.570 of
- - - - - / Runoff Depth= 1:82"
Tc =11.9 min
C =0.31
U�iiii /iiiiiiiii�'
1 2 3
Time (hours)
p Runoff

10 -YR, 24 -HR STORM EVENT
SWAN TRAIL LEVEL SPREADER Q10_3 Rainfall Duration =60 min, Inten =5.88 in /hr
Prepared by Microsoft Printed 6/9/2015
HydroCADO 10.00 s/n 05088 © 2011 HydroCAD Software Solutions LLC Paae 3
Summary for Pond 6P: MH -1
[57] Hint: Peaked at 200.70' (Flood elevation advised)
Inflow Area = 3.750 ac; 0.00% Impervious, Inflow Depth = 1.82"
Inflow =
6.89 cfs @
0.20 hrs, Volume=
0.570 of
Outflow =
6.89 cfs @
0.20 hrs, Volume=
0.570 af, Atten= 0 %, Lag= 0.0 min
Primary =
1.34 cfs @
0.20 hrs, Volume=
0.127 of
Secondary=
5.55 cfs @
0.20 hrs, Volume=
0.443 of
Routing by Stor -Ind method, Time Span= 0.00 -3.00 hrs, dt= 0.01 hrs
Peak Elev= 200.70'@ 0.20 hrs
Device Routinq Invert Outlet Devices
#1 Primary 196.80' 4.6" Round Culvert L= 7.0' RCP, groove end projecting, Ke= 0.200
Inlet/ Outlet Invert= 196.80'/ 196.50' S=0.0429'/' Cc= 0.900
n= 0.010 PVC, smooth interior, Flow Area= 0.12 sf
#2 Secondary 199.80' 24.0" Round Bypass
L= 25.0' RCP, groove end projecting, Ke= 0.200
Inlet/ Outlet Invert= 199.80'/ 196.85' S=0.1180'/' Cc= 0.900
n= 0.012 Concrete pipe, finished, Flow Area= 3.14 sf
Primary OutFlowMax =1.34 cfs @ 0.20 hrs HW= 200.70' (Free Discharge)
t-1 =Culvert (Inlet Controls 1.34 cfs @ 11.59 fps)
Secondary OutFlowMax =5.55 cfs@ 0.20 hrs HW= 200.70' (Free Discharge)
`--2= Bypass (Inlet Controls 5.55 cfs @ 4.04 fps)

10 -YR, 24 -HR STORM EVENT
SWAN TRAIL LEVEL SPREADER Q10_3 Rainfall Duration =60 min, Inten =5.88 in /hr
Prepared by Microsoft Printed 6/9/2015
HydroCADO 10.00 s/n 05088 © 2011 HydroCAD Software Solutions LLC Paae 4
3
0
FZ
I non-s-
6.89 cfs
7- �y -
5 55 cfs"
5_
4.. --
2-?-
1
Oat
0
Pond 6P: MH -1
Hydrograph
Inflow Area =3.750 ac
Peak Elev =200.70'
1 2 3
Time (hours)
■ Inflow
Outflow
❑ Primary
❑ Secondary

Or
Figure 6.40b Detail of level spreader cross section.
000 000
000 000
000 .0-0
000 000
000 000,
/0", --ft 4ftw -ftft ftftm�
,CLASS B RIPRAP BYPASS CHANNEL
(NTS)
7 AOO �10
NP
FUTURE ROAD CULVER7
(TO BE SIZED LATER)
226
B t iW mV PACT
SUMMARY
CQ
PAST AREA I
.4
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Z
E
ZONE 1®
PERM 200 SF
TEMP — 0 SF
ZONE 2.-
PERM — 13 0 S F "REVISED
P."
7:32 am Jun 16, 20
,
TEMP 0 SF ---
C)
co
MPAC--',- AREA 2*-.
ZONE I PERM — 0 SIF
TEMP — 180 SF