19991420 Ver 1_COMPLETE FILE_19991221

State of North Carolina
Department of Environment
and Natural Resources
Division of Water Quality
James B. Hunt, Jr., Governor
Bill Holman, Secretary
Kerr T. Stevens, Director
Mr. Dennis Davis
C/O Stewart Syke
1 • •
NCDENR
NORTH CAROLINA DEPARTMENT OF
ENVIRONMENT AND NATURAL RESOURCES
March 9, 1999
Wake County
DWQ Project # 991420
APPROVAL of 401 Water Quality Certification and Neuse River Buffer Rules
City of Raleigh
PO Box 590
Raleigh, NC 27602
Dear Mr. Sykes:
You have our approval, in accordance with the attached conditions, to stabilize a stream bank at 773 St.
George Road in Raleigh as described in your application dated December 21, 1999.After reviewing your application,
we have decided that this fill is covered by General Water Quality Certification Number 3102, and that this project is
in compliance with the Neuse River Buffer rules (15A NCAC 2B .0233). This certification allows you to use
Nationwide Permit Number 13 when the Corps of Engineers issues it. In addition, you should get any other federal,
state or local permits before you go ahead with your project including (but no limited to) Sediment and Erosion
Control, Coastal Stormwater, Non-Discharge and Water Supply Watershed regulations. This approval will expire
when the accompanying 404 or CAMA permit expires unless otherwise specified in the General Certification.
This approval is only valid for the purpose and design that you described in your application. If you change
your project, you must notify use and send a new application. If the property is sold, the new owner must be given a
copy of this approval letter and is thereby responsible for complying with all conditions. If total wetland fills for his
project (now or in the future) exceed one acre, compensatory mitigation may be required as described in 15A NCAC
211 .0506 (h). For this approval to be valid, you must follow the conditions listed in the attached certification.
If you do not accept any of the conditions of this approval, you may ask for an adjudicatory hearing. You
must act within 60 days of the date that you receive this letter. To ask for a hearing, send a written petition which
conforms to Chapter 150B of the North Carolina General Statutes to the Office of Administrative Hearings, P.O. Box
27447, Raleigh, NC 27611-7447. This approval and its conditions are final and binding unless you ask for a hearing.
This letter completes the review of the Division of Water Quality under Section 401 of the Clean Water Act.
If you have any questions, please telephone John Dorney at 919-733-9646.
Sinc ,
teven
cc: Corps of Engineers Raleigh Field Office
Raleigh DWQ Regional Office
Central Files
File Copy
Wetlands/401 Unit 1621 Mail Service Center Raleigh, North Carolina 27669-1621
Telephone [phone]FAX # [phone]
An Equal Opportunity Affirmative Action Employer
50% recycled/10% post consumer paper
State of North Carolina
Department of Environment
and Natural Resources
Division of Water Quality
James B. Hunt, Jr., Governor
Bill Holman, Secretary
Kerr T. Stevens, Director
ILF!WAA
NCDENR
NORTH CAROLINA DEPARTMENT OF
ENVIRONMENT AND NATURAL RESOURCES
County aq
WQC 401 Project #
APPROVAL f 401 at?r,Qpality Certification and Neuse River Buffer Rules Dear Mr.

You have our approval, in accordance with the attached conditions, to i of
f as you described in your application dated
After reviewing your application, we have decided that this fill is covered by General Water
V Quality Certification Number 3 ?p2 This Certification allows you to use Nationwide Permit Number 13
when the Corps of Engineers issues it. This approval is also valid for the Neuse River buffer rules (15A NCAC 213
.0233). In addition, you should get any other federal, state or local permits before you go ahead with your project
including (but not limited to) Sediment and Erosion Control, Coastal Stormwater, Non-Discharge and Water Supply
Watershed regulations. Also this approval will expire when the accompanying 404 or CAMA permit expires unless
otherwise specified in the General Certification.
This approval is only valid for the purpose and design that you described in your application. If you change your
project, you must notify us and send us a new application. If the property is sold, the new owner must be given a copy of
this Certification and approval letter and is thereby responsible for complying with all conditions. This approval shall
expire when the corresponding Nationwide Permit expires or as otherwise provided in the General Certification. If total
wetland fills for this project (now or in the future) exceed one acre, compensatory mitigation may be required as described
in 15A NCAC 2H .0506 (h). For this approval to be valid, you must follow the conditions listed in the attached
certification.
If you do not accept any of the conditions of this certification, you may ask for an adjudicatory hearing. You must
act within 60 days of the date that you receive this letter. To ask for a hearing, send a written petition, which conforms to
Chapter 150B of the North Carolina General Statutes to the Office of Administrative Hearings, P.O. Box 27447, Raleigh,
N.C. 27611-7447. This certification and its conditions are final and binding unless you ask for a hearing.
This letter completes the review of the Division of Water Quality under Section 401 of the Clean Water Act. If you
have any questions, please telephone John Dorney at 919-733-9646.
Sincerely,
Attachment
cc: C s f Engineers Field Office
DWQ Regional Office
ile 4opy
Central Files
Kerr T. Stevens
.ltr
Division of Water Quality • Non-Discharge Branch
1621 Mail Service Center Raleigh NC 27669-1621 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer • 50% recycled/10% post consumer paper
http://h2o.enr.state. nc.us/wetlandc.html
R°Q"I
MEMORANDUM
TO: John Dorney Regional Contact: Beth Barnes
Non-Discharge Branch WO Supervisor: Ken Schuster
Date:
SUBJECT: WETLAND STAFF REPORT AND RECOMMENDATIONS
Facility Name City of Raleigh for Dennis Davis County Wake
Project Number 99 1420 County2
Recvd From APP Region Raleigh
Received Date 12/21/99 Recvd By Region
Project Type' streambank stabilization
Certificates Stream Stream Impacts (ft.)
Permit Wetland Wetland Wetland Stream Class Acres Feet x
Type Type Impact Score Index Prim. Supp. Basin Req. Req. 574.
F13 Stream O YO N F_ -27-34-(1) ?- NSW 30,402. F_F_ ? I -
Mitigation Wetland
MitigationType Type Acres Feet
Is Wetland Rating Sheet Attached? Q Y 0 N Did you request more info? Q Y O N
Have Project Changes/Conditions Been Discussed With Applicant? Q Y 0 N
Is Mitigation required? Q Y 0 N Recommendation: Q Issue 6 Issue/fond O Deny
Provided by Region: Latitude (ddmmss) Longitude (ddmmss)
Comments:
Minimize rip, suggest A_jacks in combination with coconut husk fiber soaked and compressed
into logs plant vegetation directly into loos; and/or use vegetative matting with willow staking and
cc: Regional Office
Central Office Page Number 1
Facility Name City of Raleigh for Dennis Davis County Wake
Project Number 99 1420 Regional Contact: Beth Barnes
Date:
Comments (continued from page 1):
cc: Regional Office
Central Office Page Number 2
PAYMENT
RECEIVED 9 914 2
DWQ ID: CORPS ACTION ID: _ _ _ _
NATIONWIDE PERMIT REQUESTED (PROVIDE NATIONWIDE PERMIT #) _ _ _ _ _
PRE-CONSTRUCTION NOTIFICATION APPLICATION
FOR NATIONWIDE PERMITS THAT REQUIRE:
1. NOTIFICATION TO THE CORPS OF ENGINEERS
2. APPLICATION FOR SECTION 401 CERTIFICATION
3. COORDINATION WITH THE NC DIVISION OF COASTAL MANAGEMENT
SEND THE ORIGINAL AND (1) COPY OF THIS COMPLETED FORM TO THE APPROPRIATE FIELD
OFFICE OF THE CORPS OF ENGINEERS (SEE AGENCY ADDRESSES SHEET). SEVEN (7)
COPIES MUST BE SENT TO THE NC DIVISION OF WATER QUALITY,
27607. PLEASE PRINT OR TYPE.
1. OWNER'S NAME: Mr. Dennis Davis APPLICANT'S NAME: City of Raleigh
2. MAILING ADDRESS: P.O. Box 590
SUBDIVISION NAME
CITY: Raleigh STATE: N.C. ZIP CODE: 27602
PROJECT LOCATION ADDRESS, INCLUDING SUBDIVISION
MAILING ADDRESS ABOVE):
773 St. Geor e Road
3. TELEPHONE NUMBER: (HOME) (WORK) 890-3030
FROM
4. IF APPLICABLE: AGENT'S NAME OR RESPONSIBLE CORPORATE OFFICIAL, ADDRESS,
PHONE NUMBER:
Stewart J. Sykes. PE: City Engineer. P.O. Box 590 Raleigh. N.C. 27602
5. LOCATION OF WORK (PROVIDE A MAP, PREFERABLY A COPY OF USGS TOPOGRAPHIC MAP
OR AERIAL PHOTOGRAPHY WITH SCALE):
COUNTY: Wake - NEAREST TOWN: Raleigh
SPECIFIC LOCATION (INCLUDE ROAD NUMBERS, LANDMARKS, ECT.) 773 St. George Road
6. IMPACTED OR NEAREST STREAM/RIVER: Tributary to Walnut Creek RIVER BASIN: Neuse
7. (a) IS PROJECT LOCATED NEAR WATER CLASSIFIED AS TROUT, TIDAL SALTWATER, (SA),
HIGH QUALITY WATERS (HQW), OUTSTANDING RESOURCE WATERS (ORW), WATER
SUPPLY (WS-I OR WS-II)? YES 0 NO ® IF YES, EXPLAIN: _ _ _ _ .
(b) IS THE PROJECT LOCATED WITHIN A NORTH CAROLINA DIVISION OF COASTAL
MANAGEMENT AREA OF ENVIRONMENTAL CONCERN (AEC)? YES E] NO
(c) IF THE PROJECT IS LOCATED WITHIN A COASTAL COUNTY (SEE PAGE 7 FOR LIST OF
COASTAL COUNTIES), WHAT IS THE LAND USE PLAN (LUP) DESIGNATION? N/A
8. (a) HAVE ANY SECTION 404 PERMITS BEEN PREVIOUSLY REQUESTED FOR USE ON THIS
PROJECT? YES ? NO ® IF YES, PROVIDE ACTION I.D. NUMBER OF PREVIOUS PERMIT AND
ANY ADDITIONAL INFORMATION (INCLUDE PHOTOCOPY OF 401 CERTIFICATION): N/A
(b) ARE ADDITIONAL PERMIT REQUESTS EXPECTED FOR THIS PROPERTY IN THE FUTURE?
YES ? NO ® IF YES, DESCRIBE ANTICIPATED WORK: _ _ _ _ _
9. (a) ESTIMATED TOTAL NUMBERS OF ACRES IN TRACT OF LAND: 0.36
(b) ESTIMATED TOTAL NUMBER OF ACRES OF WETLANDS LOCATED ON PROJECT SITE:
0
10. (a) NUMBER OF ACRES OF WETLANDS IMPACTED BY THE PROPOSED PROJECT BY:
FILLING: 0 EXCAVATION: 0
FLOODING: 0 OTHER : 0
DRAINAGE : 0 TOTAL ACRES TO BE IMPACTED: 0
(b) (1) STREAM CHANNEL TO BE IMPACTED BY THE PROPOSED PROJECT (IF RELOCATED,
PROVIDE DISTANCE BOTH BEFORE AND AFTER RELOCATION:
LENGTH BEFORE: 100 FT AFTER: 100 FT
WIDTH BEFORE (based on normal high water contours): 8 FT
AVERAGE DEPTH BEFORE: 4 FT AFTER: 4 FT
(b) (2) STREAM CHANNEL IMPACTS WILL RESULT FROM: (CHECK ALL THAT APPLY)
OPEN CHANNEL RELOCATION: PLACEMENT OF PIPE IN CHANNEL:
CHANNEL EXCAVATION: CONSTRUCTION OF A DAM/FLOODING: _ _ _ _
OTHER: Streambank stabilization
11. IF CONSTRUCTION OF A POND IS PROPOSED, WHAT IS THE SIZE OF THE WATERSHED
DRAINING TO THE POND? N/S WHAT IS THE EXPECTED POND SURFACE AREA? N/A
12. DESCRIPTION OF PROPOSED WORK INCLUDING DISCUSSION OF TYPE OF MECHANICAL
EQUIPMENT TO BE USED? (ATTACH PLANS; 81/2 BY 11 DRAWINGS ONLY)
Flatten slopes on approximately 100 LF of severely eroded streambank to a max. slope of 1.5:1 and
stabilize with filter fabric and rip-rap
13. PURPOSE OF PROPOSED WORK: Streambank stabilization
14. STATE REASONS WHY IT IS BELIEVED THAT THIS ACTIVITY MUST BE CARRIED OUT IN
WETLANDS (INCLUDE ANY MEASURES TAKEN TO MINIMIZE WETLAND IMPACTS)
N/A
15. YOU ARE REQUIRED TO CONTACT THE US FISH AND WILDLIFE SERVICE AND/OR
NATIONAL MARINE FISHERIES SERVICE REGARDING THE PRESENCE OF ANY FEDERALLY
LISTED OR PROPOSED FOR LISTING ENDANGERED OR THREATENED SPECIES OR CRITICAL
HABITAT IN THE PERMIT AREA THAT MAY BE AFFECTED BY THE PROPOSED PROJECT.
DATE CONTACTED:
16. YOU ARE REQUIRED TO CONTACT THE STATE HISTORIC PRESERVATION OFFICER
(SHPO) REGARDING THE PRESENCE OF HISTORIC PROPERTIES IN THE PERMIT AREA
WHICH MAY BE AFFECTED BY THE PROPOSED PROJECT. DATE CONTACTED
17. DOES THE PROJECT INVOLVE AN EXPENDITURE OF PUBLIC FUNDS OR THE USE OF PUBLIC
(STATE) LAND? YES ® NO Fj (IF NO, GO TO 16)
(a) IF YES, DOES THE PROJECT REQUIRE PREPARATION OF AN ENVIRONMENTAL
DOCUMENT PURSUANT TO THE REQUIREMENTS OF THE NORTH CAROLINA
ENVIRONMENTAL POLICY ACT? YES ® NO ?
(b) IF YES, HAS THE DOCUMENT BEEN REVIEWED THROUGH THE NORTH CAROLINA
DEPARTMENT OF ADMINISTRATION STATE CLEARINGHOUSE YES F? NO
IF ANSWER 17b IS YES, THEN SUBMIT APPROPRIATE DOCUMENTATION FROM THE STATE
CLEARINGHOUSE WITH THE NORTH CAROLINA ENVIRONMENTAL POLICY ACT.
QUESTIONS REGARDING THE STATE CLEARINGHOUSE REVIEW PROCESS SHOULD BE
DIRECTED TO MS. CHRYS BAGGETT, DIRECTOR STATE CLEARINGHOUSE, NORTH
CAROLINA DEPARTMENT OF ADMINISTRATION, 116 WEST JONES STREET, RALEIGH,
NORTH CAROLINA 27603-8003, TELEPHONE [phone].
18. THE FOLLOWING ITEMS SHOULD BE INCLUDED WITH THIS APPLICATION IF PROPOSED
ACTIVITY INVOLVES THE DISCHARGE OF EXCAVATED OR FILL MATERIAL INTO
WETLANDS:
(a) WETLAND DELINEATION MAP SHOWING ALL WETLANDS, STREAMS, LAKES, AND
PONDS ON THE PROPERTY (FOR NATIONWIDE PERMIT NUMBERS 14, 18, 21, 26, 29, AND 38).
ALL STREAM (INTERMITTENT AND PERMANENT) ON THE PROPERTY MUST BE SHOWN ON
THE MAP. MAP SCALES SHOULD BE 1 INCH EQUALS 50 FEET OF 1 INCH EQUALS 100 FEET
OR THEIR EQUIVALENT.
(b) IF AVAILABLE, REPRESENTATIVE PHOTOGRAPH OF WETLANDS TO BE IMPACTED BY
PRODUCT.
(c) IF DELINEATION WAS PERFORMED BY A CONSULTANT, INCLUDE ALL DATA SHEETS
RELEVANT TO THE PLACEMENT OF THE DELINEATION LINE.
(d) ATTACH A COPY OF THE STORMWATER MANAGEMENT PLAN IF REQUIRED.
(e) WHAT IS LAND USE OF SURROUNDING PROPERTY?
(fl IF APPLICABLE, WHAT IS PROPOSED METHOD OF SEWAGE DISPOSAL? _ _ _ _ _
SIGNED AND DATED AGENT AUTHORIZATION LETTER, IF APPLICABLE.
NOTE: WETLANDS OR WATERS OF THE US MAY NOT BE IMPACTED PRIOR TO:
1. ISSUANCE OF A SECTION 404 CORPS OF ENGINEERS PERMIT,
2. EITHER THE ISSUANCE OR WAIVER OF A 401 DIVISION OF WATER QUALITY
CERTIFICATION, AND
3. (IN THE TWENTY COASTAL COUNTIES ONLY), A LETTER FROM THE NORTH
CAROLINA DIVISION OF COASTAL MANAGEMENT STATING THE PROPOSED
ACTIVITY IS CONSISTENT WITH THE
ROGRAM, NORT CAROLINA COASTAL MANAGEMENT
Z Z
bVWkJ'VGENT'S SIGNATURE DATE
(AUEN'NS SIGNATURE VALID ONLY
IF AUTHORIZATION LETTER FROM
THE OWNER IS PROVIDED).
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Feb 27. 1997 Raleigh

City Of ?aleish
North Carolina
January 6, 2000
Mr. John Dorney
N.C. Division of Water Quality
4401 Reedy Creek Road
Raleigh, N.C. 27607

Re: Pre-Construction Notification Application - 773 St. George Dr.
DWQ#991420
Dear Mr. Dorney:
Please find enclosed photographs, cross sections, profile, 100' scale plan view, and
stabilization specifications for the streambank stabilization petition project located at 773
St. George Dr. as requested in your letter of December 23, 1999.
As you will note in the photographs, certain areas along the stream are severely eroded.
In those areas we propose achieve a maximum slope of 1.5:1 and to stabilize with rip-rap
and fabric. Only those areas noted as being severely eroded will be stabilized. I have
included existing cross sections at 50' intervals and at those cross sections where
stabilization is proposed rip-rap and liner is shown.
This project is located on private property with the City sharing in the costs of
construction. Please review and contact me should you have questions or require further
information at [phone].
Sincer y,
,
Marty D. izzell CPESER
Stormwater Services Engineer
Cc: file
OFFICES • 222 `NEST HARGETT STREET • POST C=F!CE BOX 59-0- RALEIGH. NORTH CAROLINA 27602
Recycled Paper
Severely Eroded
Streambank
773 St. George Road
Severely Eroded
Streambank
773 St. George Drive - Cross Section 0+00
r
Cross Section for Irregular Channel
Project Description
Worksheet Irregular Channel
Flow Element Irregular Channel
Method Manning's Formu
Solve For Channel Slope
Section Data
Mannings Coefficie 0.040
Slope 0.000000 fvft
Water Surface Ele 212.00 ft
Elevation Range .40 to 212.00
Discharge 0.00 cfs
212.00 -
211.50
211.00
210.50
210.00
209.50
209.00
0+00 0+02 0+04 0+06 0+08 0+10 0+12 0+14 0+16
V:2.0
H:1
NTS
Project Engineer: Marty D. Bizzell
c:\haestad\fmw\petition.fm2 City- of Raleigh FlowMaster v6.0 (614b]
01/06/00 01:27:04 PM © Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA [phone] Page 1 of 1
773 St. George Dr. Cross Section 0+50
Cross Section for Irregular Channel
Project Description
Worksheet Irregular Channel -
Flow Element Irregular Channel
Method Manning's Formula
Solve For Channel Slope

Section Data
Mannings Coefficie 0.040
Slope 0.000000 ft/ft
Water Surface Ele 212.00 ft
Elevation Range .70 to 212.00
Discharge 0.00 cfs
212.OQ;
211.50
211.00
210.50
210.00
209.50
0+00 0+10 0+20 0+30 0+40 0+50 0+60 0+70 0+80 0+90
V:6.01\
H:1
NTS
I
Project Engineer: Marty D. Bizzell
c:\haestad\fmw\petition.fm2 City of Raleigh FlowMaster v6.0 (614b]
01/06/00 01:27:21 PM 0 Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA' [phone] Page 1 of 1
Y
773 St. George Dr. Cross Section 1+00
Cross Section for Irregular Channel
Project Description
Worksheet Irregular Channel -
Flow Element Irregular Channel
Method Manning's Formula
Solve For Channel Slope

Section Data
Mannings Coefficie 0.040
Slope 0.000000 ft/ft
Water Surface Ele 212.00 ft
Elevation Range .00 to 212.00
Discharge 0.00 cfs
212.00:
211.50
211.00
210.50
210.00 \
0+00 0+02 0+04 0+06 0+08 0+
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0+12 0+14 0+16 0+18
V:3.01
H:1
NTS
Project Engineer: Marty D. Bizzell
c:\haestad\fmw\petition.fm2 City of Raleigh FlowMaster v6.0 [614b]
01/04/00 05:47:34 PM © Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA [phone] Page 1 of 1
773 St. George Dr. - Cross Section 1+50
Cross Section for Irregular Channel
Project Description
Worksheet Irregular Channel -
Flow Element Irregular Channel
Method Manning's Formula
Solve For Channel Slope

Section Data
Mannings Coefficie 0.040
Slope 0.000000 fuft
Water Surface Ele 214.00 ft
Elevation Range .60 to 214.00
Discharge 0.00 cfs
214.00,-.-
213.50
213.00
212.50
212.00
211.50
211.00
210.50
0+00 0+05 0+10 0+15 0+20 0+
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0+30 0+35 0+40 0+45 0+50 0+55
V:4.01\
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Project Engineer: Marty D. Bizzell
c:\haestad\fmw\petition.fm2 City of Raleigh FlowMaster v6.0 (614b]
01/04/00 05:54:39 PM ©Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA [phone] Page 1 of 1
773 St. George Dr. - Cross Section 2+00
Cross Section for Irregular Channel
Project Description
Worksheet Irregular Channel -
Flow Element Irregular Channel
Method Manning's Formula
Solve For Channel Slope

Section Data
Mannings Coefficie 0.040
Slope 0.000000 ft/ft
Water Surface Ele 214.00 ft
Elevation Range .20 to 214.00
Discharge 0.00 cfs
214
213.
213.
212.
212,
211,
211.00
0+00 0+02 0+04 0+06 0+08 0+10 0+12 0+14 0+16 0+18 0+20
V:3.0
H:1
NTS
. Project Engineer: Marty D. Bizzell
c:\haestad\fmw\petition.fm2 City of Raleigh FlowMaster v6.0 (614bj
01/04/00 05:58:34 PM © Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA [phone] Page 1 of 1
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CENTRAL ENGINEERING SHEET of
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Chapter 19
RIPRAP
Definition
A permanent, erosion-resistant ground cover of large, loose, angular stone.
Purposes
1. To protect the soil surface from the erosive forces of concentrated runoff.
2. To slow the velocity of concentrated runoff while enhancing the potential for infiltration.
3. To stabilize slopes with seepage problems and/or non-cohesive soils.
Conditions Where Practice Applies
To soil-water interfaces where the soil conditions, water turbulence and velocity, expected vegetative cover,
etc., are such that the soil may erode under the design flow conditions. Riprap may be used, as appropriate, at
storm drain outlets, on channel banks and/or bottoms, roadside ditches, drop structures, at the toe of slopes,
etc.
Design Criteria
Gradation
The riprap shall be composed of a well-graded mixture down to the one-inch size particle such that 50% of the
mixture by weight shall be larger than the d50 size as determined from the design procedure. A well-graded
mixture as used herein is defined as a mixture. composed primarily of the larger stone sizes but with a sufficient
mixture of other sizes to fill the progressively smaller voids between the stones. The diameter of the largest
stone size in such a mixture shall be 1.5 times the d50 size.
The designer, after determining the riprap size that will be stable under the flow conditions, shall consider that
size to be a minimum size and then, based on riprap gradations actually available in the area, select the size or
sizes that equal or exceed the minimum size. The possibility of damage by children shall be considered in
selecting a riprap size, especially if there is nearby water to toss the stones into.
Thickness
The minimum thickness of the riprap layer shall be 1.5 times the maximum stone diameter but not less than 6
inches.
Quality of Stone
Stone for riprap shall consist of field stone or rough unhewn quarry stone of approximately rectangular shape.
The stone shall be hard and angular and of such quality that it will not disintegrate on exposure to water or
weathering and it shall be suitable in all other respects for the purpose intended. The specif ic gravity of the
individual stones shall be at least 2.5.
Rubble concrete may be used provided it has a density of at least 150 pounds per cubic foot, and otherwise
meets the requirements of this Standard and Specification.
Filter
A filter is a layer of material placed between the riprap and the underlying soil surface to prevent soil movement
into and through the riprap.
160
Riprap shall have a filter placed under it when either of the following conditions exists:
1. The riprap is not well graded down to the one-inch size particle.
2. Riprap is placed on the side slopes of a channel and the soil is sand-size or finer with a plasticity index,
PI, less than 10. This requirement applies to slopes having this soil in lenses or layers greater than three
inches in thickness.
A filter can be of two general forms. One is a single layer of plastic filter cloth manufactured for that express
purpose. The plastic filter cloth shall be woven of polypropylene monofilament yams and shall be equivalent to
"Poly-Filter X° as manufactured by Carthage Mills, Inc., Cincinnati, Ohio. Another is a properly graded layer of
sand, gravel, or stone.
The criteria for the design of an aggregate filter is as follows:
d15 Riprap 5 5 d15 Filter 255
d85 Filter d85 Base
in which d15 and d85 is the size of base, filter or riprap material of which 15 and 85 percent respectively is finer.
The base means the soil layer underneath the filter. The filter shall be graded down to sand-size particles.
Riprap that is 12* and larger shall not be dumped directly onto the plastic filter cloth since it may tear or displace
the filter cloth. Instead, a 4-inch minimum thickness blanket of gravel shall be placed over the filter cloth or the
riprap shall be placed directly on the filter cloth by hand or by the bucket of the equipment. Side slopes shall be
2:1 or flatter in order for the gravel not to slide down the filter cloth before placing the riprap.
Construction Specifications
1. The subgrade for the riprap or filter shall be prepared to the required lines and grades. Any fill required in
the subgrade shall be compacted to a density approximating that of the surrounding undisturbed material.
2. The rock or gravel shall conform to the specified grading limits when installed respectively in the riprap or
filter.
3. Plastic filter cloth shall be protected from punching, cutting or tearing. Any damage other than an
occasional small hole shall be repaired by placing another piece of cloth over the damaged part or by
completely replacing the cloth. All overlaps whether for repairs or for joining two pieces of cloth shall be a
minimum of one foot.
4. The stone for the filter and riprap may be placed by equipment. Both filter and riprap shall each be
constructed to the full course thickness in one operation and in such a manner to avoid displacement of
the underlying materials. The stone for filter and riprap shall be delivered and placed in a manner that will
insure that the filter and riprap each shall be reasonably homogeneous with the smaller stones and spalls
filling the voids between the larger stones. Riprap shall be placed in a manner to prevent damage to the
filter blanket. Hand placing will be required to the extent necessary to prevent damage to the permanent
works.
Maintenance
Once a riprap installation has been completed, it should require very little maintenance. it should, however, be
inspected periodically to determine if high flows have caused scour beneath the riprap or dislodged any of the
stone. If repairs are needed, they should be accomplished immediately.
161
SIZES FOR RIPRAP
AND EROSION CONTROL STONE
- N.C. Department of Transportation Specifications -

RIPRAP EROSION CONTROL SLOPE
PROTECTION"
Class Class Class Class
1 2 A B
Percent
5 to 200 lbs. 25 to 250 lbs. 2" to 6" 5" to 15" ,fig Passing
(15 to 8" 90-100
• 30% shall 60% shall 300 lbs.) 4" 30-70
weigh a minimum weigh a minimum 2 1/2" 10-35
of 60 lbs. each of 100 lbs. each 3/4" 0-5
• No more than No more than 10%
tolerance Or use
10% shall 5% shall weigh top & No. 4 stone,
bottom i.e., 1 1/2" to
weigh less less than 50 lbs. sizes 3/4"
than 15 lbs. ea. each. No gradation No gradation
specified specified
Also, Class A
2-6", material
• Not an NC-DOT Standard Specification
162
NCDENR
JAMES B: HUNT JR.
'GOVERNOR
BILL HOLMAN
SECRETARY
KERR T.STEVENS
;ZIRECTOR
NORTH CAROLINA DEPARTMENT OF
ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WATER QUALITY
December 23, 1999
Mr. Dennis Davis
PO Box 590
Raleigh NC 27602
RE: Streambank Work-Tributary Walnut Creek
Wake County
DWQ# 991420
The Division, of Water Quality has reviewed your submittal for a 404 permit for Wake
County. Your application was not complete since the streambank work plan included with
your application did not depict the actual work to be conducted on the streambank. For the
work you proposed, you must include detailed plans (including cross sectional profiles) of the
pattern, plan, and profile of the stream in question. This information should also include
documentation (photos would suffice) demonstrating the need for the project and detailed
plans of any structures to be used for stabilization purposes. Additionally, bioengineering (i.e.,
using root wads instead of just riprap) may be required of this project. Please submit this
information (including any information regarding riparian vegetation planting). More specific
requirements can be obtained by calling Mr. Todd St. John at 919-7339584. This information
is needed by DWQ in order for us to decide whether this project as proposed is practicable.
I can be reached at 733-1786 if you have any questions. Until this information is received, I
will request (by copy of this letter) that the Corps of Engineers place this project on hold.
Also, the project will be placed on hold for our processing due to the incomplete information
as per 15A NCAC 214 .0507(a)(4).
Sincerely,
John R. Dorney
Water Quality Certification Program
Cc: Beth Barnes, Raleigh DWQ Regional Office
Wilmington District of Corps of Engineers
Raleigh Field Office of Corps of Engineers
John Dorney
Central Files
1621 MAIL SERVICE CENTER, RALEIGH; NORTH CAROLINA 27699-1 ri21
:vebsite: esb. eh nr. state. nc. us PHONE 9 i 9-733-9960 FAX [phone]-:59
AN EQUAL OPPORTUNITY / AFFIRMATIVE ACTION EMPLOYER - 50% RECYCLED/10% POST-CONSUMER PAPER
00381131
991420
PgYMFNT
llt'C6Fa
NC DEPT OF ENVIRONMENT & NATURAL RESOURC
NC DIVISION OF WATER QUALITY
4401 REEDY CREEK RD
RALEIGH NC 27607
NUMBER DATE GR. AMOUNT ::DISCOUNT TAX ADD. CHRG. NET AMOUNT
ST GEORGE RD 12/08/99 200.00 .00 .00 .00 200.00
1f i.