20160804 Ver 2_401 Application_20200925

DWR
Division of Water Resources
Pre -Construction Notification (PCN) Form
September 1, 2020 Ver 3.2
Initial Review
Has this project met the requirements for acceptance in to the review process?*
r Yes
r No
Is this project a public transportation project?*
C Yes IT No
Change only if needed.
BIMS # Assigned
20160804
Is a payment required for this project?*
r No payment required
r Fee received
r Fee needed - send electronic notification
Reviewing Office *
Wilmington Regional Office - [phone]
Information for Initial Review
Ia. Name of project:
EAGLE ISLAND Cell 1 Improvements, Spillways 1-3
1a. Who is the Primary Contact?*
Emily Hughes
1b. Primary Contact Email:*
[e-mail]
Date Submitted
9/25/2020
Nearest Body of Water
Brunswick River
Basin
Cape Fear
Water Classification
SA, SC
Site Coordinates
Latitude:
34.193763
A. Processing Information
County (or Counties) where the project is located:
Brunswick
Is this a NCDMS Project
r Yes IT No
Longitude:
-77.962804
Is this project a public transportation project?*
r Yes r No
1a. Type(s) of approval sought from the Corps:
r Section 404 Permit (wetlands, streams and waters, Clean Water Act)
W Section 10 Permit (navigable waters, tidal waters, Rivers and Harbors Act)
Version#*
2
What amout is owed?*
IT $240.00
r $570.00
Select Project Reviewer*
Robb Mairs:eads\rlmairs2
1c. Primary Contact Phone:*
[phone]
1b. What type(s) of permit(s) do you wish to seek authorization?

W Nationwide Permit (NWP)
r Regional General Permit (RGP)
r Standard (IP)
1c. Has the NWP or GP number been verified by the Corps?
t^ Yes r No
Nationwide Permit (NWP) Number:
NWP Numbers (for multiple NWPS):
1d. Type(s) of approval sought from the DWR:
W 401 Water Quality Certification - Regular
r Non-404 Jurisdictional General Permit
r Individual Permit
7 - Outfall Structures/ Intake
le. Is this notification solely for the record because written approval is not required?
For the record only for DWR 401 Certification:
For the record only for Corps Permit:
F- 401 Water Quality Certification - E)press
r Riparian Buffer Authorization
1f. Is this an after -the -fact permit application?*
C Yes r No
1g. Is payment into a mitigation bank or in -lieu fee program proposed for mitigation of impacts?
r Yes r No
1g. Is payment into a mitigation bank or in -lieu fee program proposed for mitigation of impacts?
C Yes C No
Acceptance Letter Attachment
1h. Is the project located in any of NC's twenty coastal counties?
r Yes r No
1i. lathe project located within a NC DCM Area of Environmental Concern (AEC)?
r Yes f No
1j. Is the project located in a designated trout watershed?
C Yes r No
F. Applicant Information
1d. Who is applying for the permit?
fJ Owner W Applicant (other than owner)
le. Is there an Agent/Consultant for this project?*
r Yes r No
2. Owner Information
2a. Name(s) on recorded deed:
US OF AMERICA MARITIME COMM / DEPARTRMENT OF THE ARMY
2b. Deed book and page no.:
Null
2c. Responsible party:
2d.Address
Street Address
MARITIME ADMINISTRATION / 1200 NEW JERSEY AVENUE SE
Address Line 2
city
Washington
Postal / Zip Code
20590
2e. Telephone Number:
[phone]
2g. Email Address:*
emily. b. hug [e-mail]
C Unknown
Slate / Rmnce / Region
DC
Country
USA
2f. Fax Number:
r- Yes r No
r Yes r No
u

3. Applicant Information (if different from owner)
3a. Name:
Emily Hughes
3b. Business Name:
US ARMY CORPS OF ENGINEERS, WILMINGTON DISTRICT
3c.Address
Street Address
69 Darlington Ave
Address Line 2
City
Wilmington
Fbstal / Zip Code
28403
3d. Telephone Number:
[phone]
3f. Email Address:*
[e-mail]
C. Project Information and Prior Project History
1. Project Information
1b. Subdivision name:
ff appropriate)
1c. Nearest municipality/ town:
Wilmington
2. Project Identification
2a. Property Identification Number:
311600286346
2c. Project Address
Street Address
Address Line 2
City
Pbstal / Zip Code
3. Surface Waters
3a. Name of the nearest body of water to proposed project:*
Brunswick River
3b. Water Resources Classification of nearest receiving water:*
SA, SC
3c. What river basin(s) is your project located in?*
Cape Fear
3d. Please provide the 12-digit HUC in which the project is located.
03030005
4. Project Description and History
Slate / Province / Fbgion
NC
Country
USA
3e. Fax Number:
2b. Property size:
450
State / Rovince / Fbgion
Country
4a. Describe the existing conditions on the site and the general land use in the vicinity of the project at the time of this application:*

Eagle Island Confined Disposal Facility (CDF) is the primary disposal site for dredged material in the upper portion of the Wilmington Harbor. The initial CDF dikes were constructed in
the late 1970's and over successive years of dredging, the area has been filled and the dikes have been raised. The current configuration consists of three cells; Cell 1, Cell 2 and Cell
3, with diked areas of approximately 238, 273 and 274 acres, respectively. Outside the current CDF dikes, there are jurisdictional wetlands regulated under Section 404 of the Clean
Water Act and Section 10 of the Rivers and Harbors Act. These wetlands are influenced by tidal flows of both the Brunswick and the Cape Fear Rivers (Figure 1).
Cell 1 contains 3 spillway systems, of which only Spillway 1 is currently operable (see Figure 2). In 2009, Spillway 1 was relocated from the Brunswick River side of Cell 1 to the Cape
Fear River side after a dike breach occurred, causing the spillway structure to collapse.
During routine maintenance dredging of the upper portion of the Wilmington Harbor, hydraulic cutterhead pipeline dredges discharge a slurry of dredged material and water into the
contained cell. The slurry fills the cell and the material settles out. The spillway or spillways that release the "clean" water from the cell contain stop logs (weirs) that can be manipulated
to hold back water or allow more to flow. During every maintenance dredging contract, the contractor is required to monitor turbidity twice daily in the receiving river to assure that water
quality levels do not exceed the NC State standard of 25 NTUs.
Waters surrounding Eagle Island Cell 1 are listed as Primary Nursery Area (PNA) and are of the NCDWR surface water classifications SA and SC. The project is also located within a
DCM Area of Environmental Concern (AEC), as established by the Coastal Resources Commission.
Due to high vessel traffic, the widening of the Turning Basin Extension and proposed widening and deepening of the Wilmington Harbor project, the Corps is proposing to relocate
Spillway #1 to the west side of Cell 1.
4b. Have Corps permits or DWR certifications been obtained for this project (including all prior phases) in the past?*
B Yes f No r- Unknown
4c. If yes, please give the DWR Certification number or the Corps Action ID (exp. SAW-0000-00000).
Individual Cert #4113 issued April 21, 2017
DWR # 16-0804
Project History Upload
4d. Attach an 8 1/2 X 11 excerpt from the most recent version of the USGS topographic map indicating the location of the project site. (for DWR)
4e. Attach an 8 1/2 X 11 excerpt from the most recent version of the published County NRCS Soil Survey map depicting the project site. (for DWR)
4f. List the total estimated acreage of all existing wetlands on the property:
300
4g. List the total estimated linear feet of all existing streams on the property:
4h. Explain the purpose of the proposed project:*
To provide adequate drainage capabilities for Cell 1, Eagle Island that results in minimal damage to the surrounding freshwater tidal marsh.
4i. Describe the overall project in detail, including indirect impacts and the type of equipment to be used:*
Spillway Improvements
Spillway 1 will be relocated to the west side of Cell 1 (near its pre-2009 location). Spillways 2, and 3 will be removed and replaced in their same locations. New 30-inch diameter high -
density polyethylene (HDPE) pipes will be used through the dike embankment. Pipe bedding will be used underneath and also as backfill around the majority of the new pipe length. The
pipe bedding will consist of a silty sand (SM) or clayey sand (SC) with greater than 25 % fine material passing the No. 200 sieve (P200 > 25%). A filter diaphragm and horizontal sand
drain will be constructed on the portion of the spillway pipe near where it exits the dike. The filter diaphragm and horizontal sand drain will consist of material meeting the requirements of
ASTM C33 fine aggregate material. The configuration of the filter diaphragm and horizontal sand drain is based on the recommendations found in Chapter 6 of the Federal Emergency
Management Agency Technical Manual: Conduits through Embankment Dams, dated September 2005. The new 30-inch diameter HDPE pipes will be connected to the existing HDPE
outfall pipe outside the dike embankment draining to the Brunswick River. The timber cribbing support, if existing, will be left in place.
For Spillway 1, the existing walkway, spillway risers, spillway grating, and spillway anchors are to be removed and relocated from the Cape Fear side to the Brunswick side at the toe of
the new dike embankment step-in. Two new4-foot riser sections are to be added to Spillways 1 as well as a ladder installed on the new4-foot spillway riser sections.
For Spillways 2 and 3, the existing structural components will be demolished and removed from site and all new components will be fabricated newand installed.
The structure will be approximately 5.3' above Mean High Water (M.H.W). This is equal to an Elevation of +7.1' NAVD88. The pipe support structures for all three proposed spillways will
extend 30' from the toe of the newtoe berm into the marsh. This equates to an overwater area of 120 square feet per spillway. The 6x6 timber piles are spaced 8' apart and are driven
a minimum of 12' into the ground. All three pipe support structures are oriented in a western direction.
Installation
The piles are 6x6 timber piles typically vibrated into place. For each 30' pipe support, approximately 8 piles are used. The work has typically been achieved in the past utilizing a
vibratory attachment on a long reach excavator to install the piles from the landside. The contractor will be required to use mats in the marsh area.
In cases where the structure needs to be installed from the waterside a backhoe is mounted on a small barge get the cribbing in at high tide. Some Contractors have used a
pump/waterjet to assist with the pile installation. The waterjet is directed at the tip of the pile (typically underwater) to help loosen the soil and allow the pile to sink into the ground.
With proper care and when utilized correctly, mats typically do not cause permanent damage to the wetlands. Contractors are held responsible for restoration in the event wetland
damage occurs.
Sediment and Erosion Control
All sediment and erosion control measures will be installed prior to or in conjunction with the start of construction and will be maintained throughout the period of construction. Sediment
from the work site will be contained on site and not allowed to enter adjacent regulated wetlands or waters. Temporary and permanent sediment and erosion control measures will be
provided to stabilize all disturbed areas. Sediment and erosion control measures will include installation of temporary silt fence and seeding and mulching.
4j. Please upload project drawings for the proposed project.
EI21_CN101_overall-site-plan.pdf 4.39MB
EI21_CN102_east-site-plan.pdf 1.31 MB
E121_CN302_spillway_sections.pdf 475.84KB
EI21_CN501_Celll-2-3_SECP_Details.pdf 820.63KB
EI21_5101_spillwayl_profile.pdf 827.78KB
EI21_S102_spillway1_profile.pdf 897.76KB
5. Jurisdictional Determinations

5a. Have the wetlands or streams been delineated on the property or proposed impact areas?*
r Yes r No r Unknown
Comments:
5b. If the Corps made a jurisdictional determination, what type of determination was made?*
r Preliminary r Approved r Not Verified r Unknown r N/A
Corps AID Number:
5c. If 5a is yes, who delineated the jurisdictional areas?
Name (if known): Teresa Young, Jeff Richter
Agency/Consultant Company: USACE
Other:
5d. List the dates of the Corp jurisdiction determination or State determination if a determination was made bythe Corps or DWR
A site visit of the project area was made by Jeff Richter and Teresa Young of the US Army Corps of Engineers Wilmington District Office. During this site visit it was determined that
there were wetlands existing within the project area surrounding the existing dikes (flagged by Richter and Young).
5d1. Jurisdictional determination upload
6. Future Project Plans
6a. Is this a phased project?*
r Yes r No
7b. If yes, explain.
Improvements to the overall CDF will occur one cell at a time. This phased approach may occur over a period of up to 4-5 years, as funding becomes available.
Are any other NWP(s), regional general permit(s), or individual permits(s) used, or intended to be used, to authorize any part of the proposed project or related activity?
No.
D. Proposed Impacts Inventory u
1. Impacts Summary
la. Where are the impacts associated with your project? (check all that apply):
W Wetlands F Streams -tributaries r Buffers
r Open Waters F Pond Construction
2. Wetland Impacts
2a1 Reason (?)
2b. Impact type * (')
2c. Type of W.
2d. W. name *
2e. Forested *
2C Type of
2g. Impact
Jurisdicition*(?)
area*
S illwa 1
P Y
Overland construction
T
Tidal Freshwater Marsh
Brunswick River Marsh
No
DWR
0.003
1
(acres)
Spillway 2
Overland construction
T
Tidal Freshwater Marsh
Brunswck River Marsh2
DWR
0.003
(acres)
Spillway 3
Overland construction
T
Tidal Freshwater Marsh
k River Marsh3
DWR
0.003
(acres)
2g. Total Temporary Wetland Impact
0.009
2g. Total Wetland Impact
0.009
2g. Total Permanent Wetland Impact
0.000
2h. Comments:
Each structure is approximately 120 sq ft; estimated temporary impact area calculated at 150 sq ft per structure.
E. Impact Justification and Mitigation
1. Avoidance and Minimization
1a. Specifically describe measures taken to avoid or minimize the proposed impacts in designing the project:

All 3 spillways are being constructed in the same locations that have been used in the past. Length of structures has been minimized as much as
possible to avoid impacts to tidal wetlands.
Construction in areas below the Mean High Water line (MHW) is proposed to occur outside of the Primary Nursery Area (PNA) moratorium dates of 1
April — 31 July to avoid death or harm to anadromous fish.
No federally listed endangered or threatened species, water quality, fish and wildlife resources, or archaeological or cultural resources will be
significantly impacted by the proposed project.
1b. Specifically describe measures taken to avoid or minimize the proposed impacts through construction techniques:
Temporary silt fencing will be erected; contractor will be required to use timber mats when using heavy equipment in jurisdictional wetlands.
2. Compensatory Mitigation for Impacts to Waters of the U.S. or Waters of the State
2a. Does the project require Compensatory Mitigation for impacts to Waters of the U.S. or Waters of the State?
r Yes r No
2b. If this project DOES NOT require Compensatory Mitigation, explain why:
No permanent impacts are associated with the 3 spillway structures. 35.5. acres of fill impacts (toe berm) have already been mitigated for through purchase of wetland mitigation bank
credits.
F. Stormwater Management and Diffuse Flow Plan (required by DWR)
1. Diffuse Flow Plan
1a. Does the project include or is it adjacent to protected riparian buffers identified within one of the NC Riparian Buffer Protection Rules?
r Yes r No
If no, explain why:
No diffuse flow plan required.
2. Stormwater Management Plan
2a. Is this a NCDOT project subject to compliance with NCDOT's Individual NPDES permit NCS000250?*
r Yes r No
2b. Does this project meet the requirements for low density projects as defined in 15ANCAC 02H .1003(2)?
r Yes r No
Comments:
G. Supplementary Information
1. Environmental Documentation
1a. Does the project involve an expenditure of public (federal/state/local) funds or the use of public (federal/state) land?*
r Yes r No
V
1b. If you answered "yes" to the above, does the project require preparation of an environmental document pursuant to the requirements of the National or State (North Carolina)
Environmental Policy Act (NEPAUSEPA)?*
r Yes r No
Comments:*
This is a federal project that utilizes federal funds. SEPA requirements were fulfilled with the original permit for the toe berm construction.
2. Violations (DWR Requirement)
2a. Is the site in violation of DWR Water Quality Certification Rules (15ANCAC 2H .0500), Isolated Wetland Rules (15A NCAC 2H .1300), or DWR Surface Water or Wetland Standards or
Riparian Buffer Rules (15A NCAC 2B .0200)? *
r Yes r No
I Cumulative Impacts (DWR Requirement)
3a. Will this project result in additional development, which could impact nearby downstream water quality?*
r Yes r No
3b. If you answered "no," provide a short narrative description.
This is a federal project on federal land.
4. Sewage Disposal (DWR Requirement)
4a. Is sewage disposal required by DWR for this project?*
r Yes r Nor N/A

5. Endangered Species and Designated Critical Habitat (Corps Requirement)
5a. Will this project occur in or near an area with federally protected species or habitat?*
r Yes r No
5b. Have you checked with the USFWS concerning Endangered Species Act impacts?*
r Yes r No
5c. If yes, indicate the USFWS Field Office you have contacted.
Raleigh
5d. Is another Federal agency involved?*
r Yes r No
What Federal Agency is involved?
NMFS PRD and HCD
Se. Is this a DOT project located within Division's 1-8?
r Yes r No
St. Will you cut any trees in order to conduct the work in waters of the U.S.?
r Yes r No
5g. Does this project involve bridge maintenance or removal?
r Yes r No
5h. Does this project involve the construction/installation of a wind turbine(s)?'
r Yes r No
r Unknown
51. Does this project involve (1) blasting, and/or (2) other percussive activities that will be conducted by machines, such as jackhammers, mechanized pile drivers, etc.?
r Yes r No
If yes, please provide details to include type of percussive activity, purpose, duration, and specific location of this activity on the property.
5j. What data sources did you use to determine whether your site would impact Endangered Species or Designated Critical Habitat?
USFWS website: http://vAvN.fws.gov/nc-es/es/countyfr.html
Consultation Documentation Upload
6. Essential Fish Habitat (Corps Requirement)
6a. Will this project occur in or near an area designated as an Essential Fish Habitat?*
r Yes r No
Are there submerged aquatic vegetation (SAV) around the project vicinity?*
r Yes IT No O Unknown
6b. What data sources did you use to determine whether your site would impact an Essential Fish Habitat?*
Fish and crustacean species which may occur in the vicinity of Wilmington Harbor, and for which Fishery Management Plans (FMPs) have been
developed by the South Atlantic Fishery Management Council (SAFMC), Mid -Atlantic Fishery Management Council (MAFMC), and NMFS.
7. Historic or Prehistoric Cultural Resources (Corps Requirement)
7a. Will this project occur in or near an area that the state, federal or tribal governments have designated as having historic or cultural preservation status?*
r Yes IT No
7b. What data sources did you use to determine whether your site would impact historic or archeological resources?*
Determination from NC Clearinghouse response on Draft EA from Department of Cultural Resources; there are no anticipated impacts to historic or
archeological resources.
7c. Historic or Prehistoric Information Upload
8. Flood Zone Designation (Corps Requirement)
8a. Will this project occur in a FEMA-designated 100-year floodplain?*
r Yes r No
8b. If yes, explain how project meets FEMA requirements:
Although the project will be constructed within a FEMA-designated 10-year floodplain, it is not anticipated to affect the base flood or floodflows within
the surrounding area.
8c. What source(s) did you use to make the floodplain determination?*
North Carolina Flood Risk Information System (FRIS) at http://fris.nc.gov/fris/index.aspx?FIPS=129&ST=NC&user=General Public. Map Numbers:
3720311600K and 3720311700K; hftp://www.ncfloodrmps.w"
Miscellaneous

Comments
Miscellaneous attachments not previously requested.
Cell 1 Spillways 1-3.pdf 2.14MB
Signature
® By checking the box and signing below, I certify that:
• I have given true, accurate, and complete information on this form;
• I agree that submission of this PCN form is a "transaction" subject to Chapter 66, Article 40 of the NC General Statutes (the "Uniform Electronic Transactions Act");
• I agree to conduct this transaction by electronic means pursuant to Chapter 66, Article 40 of the NC General Statutes (the "Uniform Electronic Transactions Act");
• I understand that an electronic signature has the same legal effect and can be enforced in the same way as a written signature; AND
• I intend to electronically sign and submit the PCN form.
Full Name:
Emily Hughes
Signature
Date
9/25/2020

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95+0060+0045+00130+00135+00SOLICITATION NO.:DESIGNED BY:DESCRIPTION1
A MARKSIZE:SUBMITTED BY:DATECONTRACT NO.:CHECKED BY:DRAWN BY:ISSUE DATE:SHEET ID
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®
US Army Corps
of Engineers
CELL 1 IMPROVEMENTSEAGLE ISLAND DISPOSAL AREABRUNSWICK COUNTY, NORTH CAROLINAU.S.ARMY CORPS OF ENGINEERSWILMINGTON DISTRICT69 DARLINGTON AVENUEWILMINGTON, NORTH CAROLINA 2840322"X34"S. STELLOJ. MITCHELLDRAWING CODE:WH 104-07-41J. MANNINGSEPTEMBER 2020TBDK. HECKENDORFFILE NAME:95% DQC REVIEWOVERALL SITE PLANCN101 EI21_CN101_overall-site-plan.dwg1. FOR GENERAL NOTES SEE SHEET GI02.
2. CONTOURS SHOWN REPRESENT THE RESULTS OF SURVEYS PERFORMED ON
4 NOVEMBER 2018 (COINCIDENTAL AERIAL LIDAR AND IMAGERY DATA) AND 31
OCTOBER - 16 NOVEMBER 2018 FOR CONTROL PANELS, SPILLWAY LOCATIONS
AND CROSS SECTIONS. THE SURVEYS WERE PERFORMED USING NC RTKN
(VRS) NETWORK CONTROL. CONTOURS ARE SHOWN IN 2-FT INTERVALS.
3. THE CONTRACTOR SHALL CLEAR AREAS WITHIN THE FOOTPRINT OF
CONSTRUCTION. SEE SECTION 31 11 00.10, CLEARING AND
GRUBBING, OF THE SPECIFICATIONS FOR ADDITIONAL CLEARING
REQUIREMENTS.
4. THE CONTRACTOR SHALL DIG SUMPS AS SPECIFIED AT SPILLWAYS.
DEPTH OF SUMPS SHALL NOT GO BELOW THE TOP OF THE SPILLWAY
FOUNDATION FOR EACH SPILLWAY.
5. AFTER BORROW AREA ACTIVITIES ARE COMPLETE, THE CONTRACTOR SHALL
RESTORE ALL EAST-WEST PARALLEL DITCHES TO WORKING CONDITION AND
INSTALL A NEW PERIMETER DITCH TO ALLOW FLOW TO SPILLWAYS. THE
CONTRACTOR SHALL CONSTRUCT A CONNECTION DITCH TO EACH SPILLWAY
FROM THE PERIMETER DITCHES.
6. FOR MORE INFORMATION REGARDING EXISTING DITCHES AND DITCH
CONSTRUCTION SEE REFERENCE DRAWINGS R-1 & R-2.
NOTES:
SCALE IN FEET
0300 300 600 900
SCALE: 1" = 300'
EAGLE ISLAND CELL 1
CAPE FEAR RIVER
BRUNSWICK RIVER
7. ALL MATERIAL REMOVED FROM THE DITCHES SHALL BE PLACED IN PILES
ALONG THE SIDE OF EACH DITCH AS SHOWN IN TYPICAL DITCH SECTIONS
AND LAYOUTS. PILES SHALL BE NO CLOSER THAN 10' FROM EACH OTHER.
8. DITCHES SHALL BE CONSTRUCTED NO CLOSER THAN 150' FROM THE INSIDE
TOE OF THE PROPOSED STEP-IN.
9. DUE TO THE SOFT, WET CONDITIONS THAT EXIST INSIDE CELL 1, THE
CONTRACTOR SHOULD ANTICIPATE MAKING SEVERAL PASSES WITH HIS
EQUIPMENT TO ACHIEVE THE TYPICAL DITCH SECTION. PONDED WATER
MAY BE ENCOUNTERED AT THE SOUTH END OF CELL 1.
10. THE CONTRACTOR SHALL OPERATE SPILLWAYS AS NECESSARY TO REMOVE
WATER. ALL DISCHARGE OF WATER INTO THE BRUNSWICK RIVER AND
CAPE FEAR RIVER SHALL MEET NC STATE WATER QUALITY STANDARDS.
11. EXISTING SPILLWAY 1 IS TO BE DEMOLISHED AND NEW SPILLWAY 1
CONSTRUCTED AT NEW LOCATION AS SHOWN. SEE SHEET CN103 FOR
MORE INFORMATION.
12. THE CONTRACTOR SHALL PREPARE A DRAINAGE PLAN FOR APPROVAL BY
THE CONTRACTING OFFICER AND/OR CONTRACTING OFFICER'S
REPRESENTATIVE. CONTRACTOR WILL CONDUCT CONSTRUCTION OPERATIONS
IN ACCORDANCE WITH THE APPROVED DRAINAGE PLAN.
SHEET CN102
SHEET CN104MATCHLINE SHEET CN103 MATCHLINE SHEET CN104SHEET CN103
MATCHLINE SHEET CN103MATCHLINE SHEET CN104CELL 2
EXTERIOR TOE BERM
EXTERIOR TOE BERM
EXTERIOR TOE BERM
INTERIOR STEP-IN & DIKE RAISE
INTERIOR STEP-IN & DIKE RAISE
EXISTING DIKE CENTERLINE ALIGNMENT
BORROW AREA LIMITS (TYP.)
PROPOSED SPILLWAY 1
PROPOSED SPILLWAY 2
PROPOSED SPILLWAY 3
SURVEY CONTROL POINT PANEL 6
N: 163,572.35
E: 2,314,580.07
ELEV: 39.80'
SURVEY CONTROL POINT PANEL 8
N: 161,118.52
E: 2,314,287.61
ELEV: 40.06'
SURVEY CONTROL POINT PANEL 7
N: 161,421.93
E: 2,312,753.58
ELEV: 39.76'
SURVEY CONTROL POINT PANEL 5
N: 164,929.49
E: 2,312,337.29
ELEV: 40.76'
SURVEY CONTROL POINT PANEL 10
N: 166,689.81
E: 2,313,021.05
ELEV: 35.75'
LIMITS OF SURVEY (TYP.)
LIMITS OF SURVEY (TYP.)EXISTING SILT FENCE (TYP.)
LEGEND
SURVEY CONTROL POINT
EXISTING SPILLWAY 1
(TO BE RELOCATED)
13. MATERIAL FOR DIKE CONSTRUCTION SHALL BE OBTAINED FROM WITHIN CELL 1. NO
EXCAVATION FOR BORROW MATERIAL WILL BE ALLOWED WITHIN 150 FEET OF THE
TOE OF CROSS DIKE 1-2 WITHIN CELL 1 OR WITHIN 150 FEET OF THE PROPOSED TOE
OF THE STEP-IN FOR THE DIKE RAISE WITHIN CELL 1.
14. BORROW AREAS SHALL BE GRADED TO PROVIDE POSITIVE DRAINAGE TOWARD THE
ACTIVE SPILLWAY(S)
15. THE CONTRACTOR SHALL SEED AND MULCH ALL DISTURBED AREAS IN ACCORDANCE
WITH SECTION 32 92 19 OF THE SPECIFICATIONS. SEE TYPICAL SECTIONS ON SHEET
CN301 FOR SEEDING AND MULCHING LIMITS.
16. THE CONTRACTOR SHALL CONSTRUCT IMPROVEMENTS TO THE DIKE EMBANKMENT,
INCLUDING STEP-INS, DIKE RAISE, AND TOE BERM CONSTRUCTION, IN ACCORDANCE
WITH SECTION 31 01 00 OF THE SPECIFICATIONS.
17. NEW REINFORCED SILT FENCE SHALL BE INSTALLED AT 5' MINIMUM DISTANCE FROM
TOE OF PROPOSED EXTERIOR TOE BERMS.
18. PROPOSED SPILLWAY OUTFALL PIPES SHALL HAVE 1 FOOT MINIMUM COVER THROUGH
DIKE EMBANKMENT AND EXTERIOR TOE BERM. IF MINIMUM COVER CANNOT BE
PROVIDED BY FOLLOWING TYPICAL SECTION DESIGNS, SUFFICIENT COVER SHALL BE
ADDED TO MEET THIS REQUIREMENT.60+0045+0040+0035+0030+0050+0055+0065+0070+0075+0080+0085+0090+0095+00100+00105+
0
0
110+
0
0
115
+
0
0
1
2
0+
0
0
125+00130+00135+00140+00145+00150+00155+00160+00165+00170+00175+00180+00185+0019
0
+
0
0 195+00200+000+00
5+00
10+00
PROPOSED SILT FENCE
PROPOSED SILT FENCE(TYP.)
20
25
30
35
40
45
5050
20
30
40
5050
46+6250+0055+0060+0065+0070+0075+0080+0085+0090+0095+00
-ELEVATION IN FEETELEVATION IN FEETDISTANCE ALONG CENTERLINE IN FEET
SCALE IN FEET
0
0
HORIZONTAL SCALE: 1" = 200'
200 200 400 600
VERTICAL SCALE: 1" = 10'
10 10 20 30
CELL 1
C E L L 1
C A P E F E A R R I V E R
TOP OF EXISTING DIKETOP OF PROPOSED DIKE - EL. 46.0'
5555
16
17 40+0050+0055+0065+0070+0075+0080+0085+0090+00100+00140+00PC46+35.3PT46+87.9PI48+21.5PC49+13.1PT50+03.4PC51+21.4PT52+43.3PC56+89.2PT60+12.4PC62+96.8PT64+39.0PC64+57.9PT66+09.1PI73+85
.0PC74+40.1
P
T
7
6
+
8
8
.
0
PC
7
7
+
1
9
.
1PT79+48.8PI81+26.4PC83+40.4PT86+28.1PC88+16.7PT93+97.5PT101+25.0PT122+31.0PT130+07.3PI46+61.9PI49+58.4PI51+82.5PI58+52.7PI63+68.2PI65+33.8PI75+64
.9PI78+37
.2PI84+84.7PI91+09.2PI100+01.9PI142+31
.6
5+00
POB 0+
0
0
.
0
STA. 46+62.0 Cells 1-2-3 =STA. 0+00 Cross Dike 1-2STA. 13+47.8 Cross
D
ike
1-2
PI Sta.65+33.8
N 164735.9
E 2313979.6
T= 75.9'
R= 700.0'
Dc= 8°11'06.4"
Lc=151.2'
E= 4.1'
PI Sta.48+21.5
N 166404.7
E 2313687.9
PI Sta.49+58.4
N 166267.8
E 2313687.9
T= 45.3'
R= 500.0'
Dc= 11°27'33.0"
Lc=90.3'
E= 2.0'
PI Sta.51+82.5
N 166047.1
E 2313728.2
T= 61.1'
R= 700.0'
Dc= 8°11'06.4"
Lc=121.9'
E= 2.7'
PI Sta.58+52.7
N 165418.3
E 2313961.0
T= 163.6'
R= 850.0'
Dc= 6°44'26.4"
Lc=323.2'
E= 15.6'
PI Sta.63+68.2
N 164899.1
E 2313947.7
T= 71.4'
R= 650.0'
Dc= 8°48'53.0"
Lc=142.2'
E= 3.9'
PI Sta.73+85.0
N 163954.5
E 2314318.6
PI Sta.75+64.9
N 163792.8
E 2314397.3
T= 124.8'
R= 875.0'
Dc= 6°32'53.1"
Lc=248.0'
E= 8.9'
PI Sta.78+37.2
N 163589.8
E 2314581.4
T= 118.1'
R= 400.0'
Dc= 14°19'26.2"
Lc=229.7'
E= 17.1'
PI Sta.84+84.7
N 162944.1
E 2314685.0
T= 144.4'
R= 1400.0'
Dc= 4°05'33.2"
Lc=287.7'
E= 7.4'
PI Sta.91+09.2
N 162319.6
E 2314649.2
T= 292.5'
R= 2000.0'
Dc= 2°51'53.2"
Lc=580.8'
E= 21.3'
PI Sta.81+26.4
N 163298.5
E 2314632.0
95+0060+0045+00135+0015 10 5
15
16
17
10 5
35 40 45
45 40
363637
35
363637
40 45
45 40
35
3636
37
40 45
45 40
C E L L 2
SOLICITATION NO.:DESIGNED BY:DESCRIPTION1
A MARKSIZE:SUBMITTED BY:DATECONTRACT NO.:CHECKED BY:DRAWN BY:ISSUE DATE:SHEET ID
B
C
D
E
F
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2 3 4 5 6 7 8 9 10
®
US Army Corps
of Engineers
CELL 1 IMPROVEMENTSEAGLE ISLAND DISPOSAL AREABRUNSWICK COUNTY, NORTH CAROLINAU.S.ARMY CORPS OF ENGINEERSWILMINGTON DISTRICT69 DARLINGTON AVENUEWILMINGTON, NORTH CAROLINA 2840322"X34"S. STELLOJ. MITCHELLDRAWING CODE:WH 104-07-41J. MANNINGSEPTEMBER 2020TBDK. HECKENDORFFILE NAME:95% DQC REVIEWSITE PLAN & PROFILESTA. 46+62 TO STA. 95+00CN102 EI21_CN102_east-site-plan.dwg1.
2.
3.
4.
NOTES:
SEE SHEETS GI02 AND CN101 FOR GENERAL AND SITE PLAN NOTES.
CONTROL POINTS ARE NOTED ON SHEET CN101.
SEE SHEET CN301 FOR TYPICAL SECTIONS.
SEE SHEETS CN303 TO CN307 FOR CROSS SECTIONS OF AREAS
ON THIS SHEET.
MATCHLINE SEE SHEET CN104
EXTERIOR TOE BERM
SEE TYPICAL SECTION 3
ON SHEET CN301
INTERIOR STEP-IN & DIKE RAISE
SEE TYPICAL SECTION 1
ON SHEET CN301
INTERIOR STEP-IN & DIKE RAISE
SEE TYPICAL SECTION 1
ON SHEET CN301
INTERIOR STEP-IN & DIKE RAISE
SEE SHEETS CN103 & CN104
MATCHLINE SEE SHEET CN103BORROW AREA LIMITS
150' FROM PROPOSED
TOE OF STEP-IN
LIMITS OF SURVEY (TYP.)
EXISTING SILT FENCE (TYP.)CELL 1-2 CROSSDIKETOP OF BERM
100' WIDE PROPOSED
REINFORCED SILT
FENCE
1'4' TYP
4'
2'
CL
N.T.S.
N.T.S.
GEOTEXTILE (ELEV. VARIES)
7.5'7.5'3.8'7.5'13.8'12'
NEW
PIPE
NEW 30" DIAMETER
HDPE PIPE SDR 11
17.5'
DIKE EMBANKMENT EXCAVATION SECTION AT SPILLWAYS
DIKE EMBANKMENT EXCAVATION SECTION AT SPILLWAYS - FILTER DIAPHRAGM
SELECT FILL AND FILTER
SAND ABOVE AND
BELOW PIPE
GEOTEXTILE
EXISTING GROUND
30" HDPE PIPE
VARIES
1' (TYP.)
2' (TYP.)
N.T.S.
STEP CONSTRUCTED
AT 12H:4V (TYP.)
NEW 30" DIAMETER
HDPE PIPE SDR 11
GEOTEXTILE (ELEV. VARIES)
NEW
PIPE
CL
SELECT FILL & FILTER SAND DETAIL
THE LAYER OF NEW GEOTEXTILE (ELEVATION
VARIES) SHALL MATCH ELEVATION OF EXISTING
GEOTEXTILE. THE NEW GEOTEXTILE SHALL OVERLAP
THE EXISTING GEOTEXTILE BY 10'.
10'
SELECT FILL AND
FILTER SAND
FILTER SAND/
FILTER DIAPHRAGM
NOTE: GEOTEXTILE IS ALSO REQUIRED AT HIGHER
ELEVATION (ELEVATION VARIES) AND SHALL BE
CONTINUOUS INTO NEW INTERIOR STEP-IN.
SEE TABLE 1 ON SHEET CN301.
1'(TYP)12'
(TYP)
STEP CONSTRUCTED
AT 12H:4V (TYP.)
THE LAYER OF NEW GEOTEXTILE (ELEVATION
VARIES) SHALL MATCH ELEVATION OF
EXISTING GEOTEXTILE. THE NEW GEOTEXTILE
SHALL OVERLAP THE EXISTING
GEOTEXTILE BY 10'.
NOTE: GEOTEXTILE IS ALSO REQUIRED AT HIGHER
ELEVATION (ELEVATION VARIES) AND SHALL BE
ONTINUOUS INTO NEW INTERIOR STEP-IN.
SEE TABLE 1 ON SHEET CN301.
4'4'
GEOTEXTILE (ELEV. VARIES)
UNDER PIPE APPROX. 10.5' WIDE
SELECT FILL ABOVE
AND BELOW PIPE
GEOTEXTILE
EXISTING GROUND
30" HDPE PIPE
8' MIN.
7.5'
3' (TYP.)
3.8'
1' (TYP.)
2' (TYP.)
N.T.S.
SELECT FILL & FILTER SAND DETAIL AT FILTER DIAPHRAGM
NOTES:
1.SEE SHEETS S101 - S102 FOR LOCATION OF FILTER
DIAPHRAGM.
2.WHEN CONSTRUCTING THE FILTER DIAPHRAGM, BRING
EMBANKMENT FILL UP IN SIMILAR LIFTS AS FILTER SAND.
FILTER SAND IN FILTER
DIAPHRAGM & HORIZONTAL
DRAIN SOLICITATION NO.:DESIGNED BY:DESCRIPTION1
A MARKSIZE:SUBMITTED BY:DATECONTRACT NO.:CHECKED BY:DRAWN BY:ISSUE DATE:SHEET ID
B
C
D
E
F
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2 3 4 5 6 7 8 9 10
®
US Army Corps
of Engineers
CELL 1 IMPROVEMENTSEAGLE ISLAND DISPOSAL AREABRUNSWICK COUNTY, NORTH CAROLINAU.S.ARMY CORPS OF ENGINEERSWILMINGTON DISTRICT69 DARLINGTON AVENUEWILMINGTON, NORTH CAROLINA 2840322"X34"S. STELLOJ. MITCHELLDRAWING CODE:WH 104-07-41J. MANNINGSEPTEMBER 2020TBDK. HECKENDORFFILE NAME:95% DQC REVIEWTYPICAL SPILLWAYSECTIONS AND DETAILSCN302 EI21_CN303_spillway_sections.dwg
SEEDING AND MULCHING
IMMEDIATELY AFTER SEEDING, FIRM ENTIRE AREA EXCEPT FOR SLOPES IN EXCESS OF
3 TO 1 WITH ROLLER NOT EXCEEDING 90 POUNDS FOR EACH FOOT OF ROLLER WIDTH.
IF SEEDING IS PERFORMED WITH CULTIPACKER-TYPE SEEDER OR HYDROSEEDING,
ROLLING MAY BE ELIMINATED.
TEMPORARY SEED SPECIES FOR SURFACE EROSION CONTROL OR OVER SEEDING SHALL
BE AS FOLLOWS:
PLANTING PERIOD COMMON NAME
15 MAR - 14 SEP BROWNTOP, PROSO OR GERMAN
(FOXTAIL) MILLET 50
15 SEP - 14 JAN RYE GRAIN 112
15 JAN - 14 MAR SPRING OATS 128
PERMANENT SEED MIXTURE SHALL BE AS FOLLOWS:
PLANTING PERIOD COMMON NAME
1 FEB - 30 APR PENSACOLA BAHIAGRASS
COMMON OR KOBE LESPEDEZA 25
SPRING OATS 32
1 MAY - 31 AUG COMMON OR KOBE LESPEDEZA 25
BROWNTOP PROSO OR GERMAN
(FOXTAIL) MILLET 30
1 SEP - 31 JAN COMMON OR KOBE LESPEDEZA 40
RYE (GRAIN)56
ADDITIONAL PERMANENT SEED SPECIES SHALL BE PLACED AS FOLLOWS:
PLANTING PERIOD COMMON NAME
1 NOV - 28 FEB COMMON BERMUDAGRASS 20
(UNHULLED)
1 MAR - 31 JUL COMMON BERMUDAGRASS 12
(HULLED)
FERTILIZER SHALL BE COMMERCIAL GRADE, FREE FLOWING, UNIFORMLY COMPOSED.
FERTILIZER SHALL BE BALANCED WITH THE INCLUSION OF TRACE MINERALS AND
MICRO NUTRIENTS.
SYNTHETIC, GRANULAR CONTROLLED RELEASE FERTILIZER CONTAINING
THE FOLLOWING MINIMUM PERCENTAGES, BY WEIGHT OF PLANT FOOD NUTRIENTS:
10 PERCENT AVAILABLE NITROGEN
10 PERCENT AVAILABLE PHOSPHORUS
10 PERCENT AVAILABLE POTASSIUM
CONTROLLED RELEASE FERTILIZER, TO USE WITH HYDROSEEDING AND COMPOSED OF PILLS
COATED WITH PLASTIC RESIN TO PROVIDE A CONTINUOUS RELEASE OF NUTRIENTS FOR AT
LEAST 6 MONTHS AND CONTAINING THE FOLLOWING MINIMUM PERCENTAGES, BY WEIGHT, OF
PLANT FOOD NUTRIENTS:
10 PERCENT AVAILABLE NITROGEN
10 PERCENT AVAILABLE PHOSPHORUS
10 PERCENT AVAILABLE POTASSIUM
MINIMUM LBS
PER ACRE
MINIMUM LBS
PER ACRE
MINIMUM LBS
PER ACRE
VEGETATIVE STABILIZATION - SEEDING
TEMPORARY SEED
PERMANENT SEED
FERTILIZER
HAY OR STRAW MULCH
STRAW
HAY
MECHANICAL ANCHOR
WOOD CELLULOSE FIBER
SOIL PREPARATION
10
SEED PERMANENT GROUND COVER FOR ALL DISTURBED AREAS WITH 3H : 1V SLOPES OR
FLATTER WITHIN 14 CALENDAR DAYS AFTER COMPLETION OF CONSTRUCTION AND ALL
DISTURBED AREAS WITH SLOPES STEEPER THAN 3H : 1V WITHIN 7 CALENDAR DAYS AFTER
COMPLETION OF CONSTRUCTION.
TEMPORARY SILT FENCE (TSF) DETAIL
WIRE FABRIC
GROUND LINE3'-0" MAX.2'-0" MIN.4"
8"
COMPACTED FILL
2' MIN' (TYP)
STEEL POST
MIN. 12.5 GA.
INTERMEDIATE
WIRES
MIN. 10 GA.
TOP & BOTTOM
WIRES
FILTER
FABRIC
24" FILTERFABRIC36" MIN WIDTH
FILTER FABRIC
(8' MAX. STANDARD STRENGTH FABRIC WITH WIRE FENCE)
MIN. 12.5 GA.
VERTICAL WIRES
STEEL
POST
(TYP)
N.T.S.
VARIES AS DIRECTED BY THE CONTRACTING OFFICER
OR HIS/HER DESIGNATED REPRESENTATIVE
MULCH SHALL BE FREE FROM NOXIOUS WEEDS, MOLD, AND OTHER
DELETERIOUS MATERIALS. MULCH MATERIALS SHALL BE NATIVE TO
THE REGION. HAY OR STRAW MULCH SHALL BE SPREAD UNIFORMLY
AT THE RATE OF 2 TONS PER ACRE. MULCH SHALL BE SPREAD BY
HAND, BLOWER-TYPE MULCH SPREADER, OR OTHER APPROVED
METHOD. MULCHING SHALL BE STARTED ON THE WINDWARD SIDE
OF RELATIVELY FLAT AREAS OR ON THE UPPER PART OF STEEP
SLOPES, AND CONTINUED UNIFORMLY UNTIL THE AREA IS COVERED.
THE MULCH SHALL NOT BE BUNCHED OR CLUMPED. SUNLIGHT SHALL
NOT BE COMPLETELY EXCLUDED FROM PENETRATING TO THE GROUND
SURFACE. ALL AREAS INSTALLED WITH SEED SHALL BE MULCHED ON
THE SAME DAY AS THE SEEDING. MULCH SHALL BE ANCHORED
IMMEDIATELY FOLLOWING SPREADING.
STALKS FROM OATS, WHEAT, RYE, BARLEY, OR RICE. FURNISH IN
AIR-DRY CONDITION AND OF PROPER CONSISTENCY FOR PLACING
WITH COMMERCIAL MULCH BLOWING EQUIPMENT. STRAW SHALL
CONTAIN NO FERTILE SEED.
HAY SHALL BE NATIVE HAY, SUDAN-GRASS HAY, BROOMSEDGE HAY,
OR OTHER HERBACEOUS MOWING. AIR-DRY CONDITION AND OF
PROPER CONSISTENCY FOR PLACING WITH COMMERCIAL MULCH
BLOWING EQUIPMENT. HAY SHALL BE STERILE, CONTAINING NO
FERTILE SEED.
MECHANICAL ANCHOR SHALL BE A V-TYPE-WHEEL LAND PACKER;
A SCALLOPED-DISK LAND PACKER DESIGNED TO FORCE MULCH INTO
THE SOIL SURFACE; OR OTHER SUITABLE EQUIPMENT.
WOOD CELLULOSE FIBER SHALL BE APPLIED AS PART OF THE
HYDROSEEDING OPERATION. THE MULCH SHALL BE MIXED AND
APPLIED IN ACCORDANCE WITH THE MANUFACTURER'S
RECOMMENDATIONS.
SOIL ON SLOPES UP TO A MAXIMUM 3-HORIZONTAL-TO-1-VERTICAL
SHALL BE TILLED TO A MINIMUM 4 INCH DEPTH. ON SLOPES BETWEEN
3-HORIZONTAL-TO-1-VERTICAL AND 1-HORIZONTAL-TO-1-, THE SOIL
SHALL BE TILLED TO A MINIMUM 2 INCH DEPTH BY SCARIFYING
WITH HEAVY RAKES, SPIKED TOOTH HARROW, CHISEL PLOWS, OR
SIMILAR IMPLEMENTS, OR OTHER SIMILAR METHOD. ROTOTILLERS
SHALL BE USED WHERE SOIL CONDITIONS AND LENGTH OF SLOPE
PERMIT. AREAS COMPACTED BY CONSTRUCTION OPERATIONS SHALL
BE COMPLETELY PULVERIZED BY TILLAGE. THE FERTILIZER MAY BE
APPLIED DURING THIS PROCEDURE.
SOIL EROSION AND SEDIMENT CONTROL MEASURES
1. ALL EROSION AND SEDIMENTATION CONTROL MEASURES NOTED SHALL BE INSTALLED PRIOR TO START OF CONSTRUCTION AND
SHALL REMAIN IN EFFECT AND BE MAINTAINED THROUGHOUT THE PERIOD OF CONSTRUCTION.
2. SEDIMENTATION FROM WORK ON THIS SITE SHALL BE CONTAINED ON THE SITE AND SHALL NOT BE ALLOWED TO COLLECT ON ANY
OFFSITE AREA OR IN WATERWAYS.
3. CONTRACTOR SHALL APPLY TEMPORARY EROSION AND SEDIMENT CONTROL MEASURES AS SHOWN ON THESE PLANS OR AS DIRECTED BY
THE CONTRACTING OFFICER OR HIS/HER DESIGNATED REPRESENTATIVE. CONTRACTOR SHALL REMOVE TEMPORARY MEASURES AS SOON
AS PERMANENT STABILIZATION OF SLOPES, DITCHES, AND OTHER EARTH CHANGES HAVE BEEN ACCOMPLISHED.
4. DAILY INSPECTION SHALL BE MADE BY THE CONTRACTOR TO DETERMINE THE EFFECTIVENESS OF EROSION CONTROL MEASURES, AND
ANY NECESSARY REPAIRS SHALL BE MADE WITHOUT DELAY.
5. PERMANENT SOIL EROSION CONTROL MEASURES FOR ANY DISTURBED LAND AREA SHALL BE STABLIZIED AS SOON AS POSSIBLE. WHEN IT
IS NOT POSSIBLE TO PERMANENTLY STABILIZE A DISTURBED AREA IMMEDIATELY AFTER COMPLETION OF GRADING WORK, TEMPORARY
SOIL EROSION CONTROL MEASURES SHALL BE IMPLEMENTED IMMEDIATELY. ALL TEMPORARY SOIL EROSION CONTROL MEASURES SHALL
BE MAINTAINED UNTIL PERMANENT SOIL EROSION CONTROL MEASURES ARE IMPLEMENTED.
6. CONTRACTOR SHALL PROVIDE PERMANENT GROUND COVER FOR ALL DISTURBED AREAS WITH 3H:1V SLOPES OR FLATTER WITHIN 14 CALENDAR
DAYS FOLLOWING THE COMPLETION OF CONSTRUCTION AND ALL DISTURBED AREAS WITH SLOPES STEEPER THAN 3H:1V WITHIN 7 CALENDAR DAYS
AFTER COMPLETION OF CONSTRUCTION.
7. SEE SECTION 32 92 19 IN THE SPECIFICATIONS FOR DETAILS REGARDING MAINTENANCE AND APPLICATION OF SEEDING,
SOIL CONDITIONERS, FERTILIZERS, AND MULCH.
TEMPORARY SILT FENCE NOTES:
1. THE EXISTING TEMPORARY SILT FENCE (TSF) LOCATED WITHIN THE FOOTPRINT OF THE PROPOSED
CELL 1 EXTERIOR TOE BERMS SHALL BE REMOVED AND DISPOSED OF OFF GOVERNMENT
PROPERTY. NEW TEMPORARY SILT FENCE SHALL BE INSTALLED AT LOCATIONS SHOWN ON THE
PLANS. THE CONTRACTOR SHALL COMPLETE ALL TEMPORARY SILT FENCE INSTALLATION PRIOR TO
COMMENCEMENT OF CLEARING AND EARTHWORK OPERATIONS.
2. WIRE FABRIC SHALL BE A MINIMUM OF 32" IN WIDTH AND SHALL HAVE A MINIMUM OF 6 LINE WIRES
WITH 12" STAY SPACING.
3. FILTER FABRIC SHALL HAVE A MINIMUM OF 36" WIDTH. FILTER FABRIC SHALL BE FASTENED
ADEQUATELY TO THE FENCE FABRIC AS DIRECTED BY THE CONTRACTING OFFICER.
4. STEEL POSTS SHALL BE 5 FEET (MIN) IN HEIGHT AND SHALL BE OF THE SELF-FASTENER ANGLE
STEEL TYPE.
5. THE CONTRACTOR SHALL INSPECT TEMPORARY SILT FENCE AT LEAST ONCE EVERY 7 DAYS AND
AFTER ANY SIGNIFICANT STORM THAT PRODUCES 0.5 INCHES OR MORE RAINFALL AT THE SITE
AND MAKE ANY REQUIRED REPAIRS IMMEDIATELY. REMOVE SEDIMENT DEPOSITS AS NECESSARY
TO PROVIDE ADEQUATE STORAGE VOLUME FOR THE NEXT RAIN AND TO REDUCE PRESSURE ON
THE FENCE. TAKE CARE TO AVOID UNDERMINING THE FENCE DURING CLEANOUT.
6. THE CONTRACTOR SHALL PERFORM ALL WORK IN SUCH A MANNER THAT STATE WATER QUALITY
STANDARDS OUTSIDE OF THE CONSTRUCTION AREA ARE NOT VIOLATED. ALL EROSION AND
SEDIMENT CONTROL MEASURES SHALL BE IN ACCORDANCE WITH THE NORTH CAROLINA EROSION
AND SEDIMENT CONTROL PLANNING AND DESIGN MANUAL.SOLICITATION NO.:DESIGNED BY:DESCRIPTION1
A MARKSIZE:SUBMITTED BY:DATECONTRACT NO.:CHECKED BY:DRAWN BY:ISSUE DATE:SHEET ID
B
C
D
E
F
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2 3 4 5 6 7 8 9 10
®
US Army Corps
of Engineers
CELL 1 IMPROVEMENTSEAGLE ISLAND DISPOSAL AREABRUNSWICK COUNTY, NORTH CAROLINAU.S.ARMY CORPS OF ENGINEERSWILMINGTON DISTRICT69 DARLINGTON AVENUEWILMINGTON, NORTH CAROLINA 2840322"X34"S. STELLOJ. MITCHELLDRAWING CODE:WH 104-07-41J. MANNINGSEPTEMBER 2020TBDK. HECKENDORFFILE NAME:95% DQC REVIEWEROSION & SEDIMENTCONTROL DETAILSCN501 EI21_CN501_Cell1-2-3_SECP_Details.dwg
151+23.52
-10
0
10
20
30
40
50
60
-10
0
10
20
30
40
50
60
0 50 100 150 200 250 300 350 400 4500-50-100-150-200-250-300-350-400-450
PROPOSED
BUMP OUT
RELOCATED
5'x5'x1.5'
CONC. PAD
NEW GEOTEXTILE
(EL. 35.0)
NEW STEEL WALKWAY
NEW 4' STEEL
RISER SECTIONS
10'x15'x1'
CONC. PAD
EXISTING
GROUND 2
1
(max.)
NEW 30" OD HDPE PIPE
EL. 23.0'
NEW GEOTEXTILE
NEW 30" OD SDR 11 HDPE PIPE
NEW
4'x8' STEEL
RISER
PROPOSED DIKE RAISE
CONNECT NEW HDPE PIPES IN ACCORDANCE
WITH MANUFACTURER'S RECOMMENDATION
CONTRACTOR TO PROVIDE 2' OF CAMBER (NOT SHOWN)STA. -0+28SELECT FILLFILTER SAND
NEW FOUNDATION
SEE S503 FOR DETAILS
SEE SELECT FILL &
FILTER SAND DETAIL
ON SHEET CN302
(EL. 29.0)
30' MIN
PIPE INVERT MIN. 2' ABOVE
M.H.W (+3.83' NAVD 88)
NEW TIMBER FRAMES
@ 8' MAX. SPANS
SUPPORTING HDPE PIPE
MAINTAIN MIN.
1' COVER
EL. 47.0'
NOTES:
THE CONTRACTOR SHALL SUBMIT A DRAINAGE PLAN FOR APPROVAL PRIOR TO
DEMOLITION AND/OR CONSTRUCTION. DRAINAGE OPERATIONS AT SPILLWAYS
AND WITHIN THE PROJECT LIMITS SHALL FOLLOW THE APPROVED DRAINAGE
PLAN.
PRIOR TO EXCAVATION REQUIRED FOR REMOVAL OF THE EXISTING SPILLWAY
SYSTEMS, THE CONTRACTOR SHALL INSTALL A TEMPORARY COFFERDAM AT
EACH SPILLWAY TO PREVENT SEDIMENTATION FROM ESCAPING THE WORK
SITE INTO THE WETLANDS. THE TEMPORARY COFFERDAMS SHALL NOT BE
REMOVED UNTIL COMPLETION OF THE SPILLWAY PIPE AND RISER
INSTALLATION AND DIKE EMBANKMENT CLOSURE AND STABILIZATION AND
PERMANENT VEGETATION HAS BEEN RE-ESTABLISHED.
THE EXISTING 30-INCH DIAMETER STEEL REINFORCED POLYETHYLENE
(SRPE)PIPES AT SPILLWAYS 2 & 3 AND THE 30-INCH DIAMETER
CORRUGATED ALUMINUM ALLOY PIPE AT SPILLWAYS 2 & 3 WITHIN THE DIKE
EMBANKMENT SHALL BE REMOVED AND DISPOSED OF IN ACCORDANCE
WITH LOCAL, STATE AND FEDERAL REGULATIONS.
REMOVE FRENCH DRAINS AT ALL EXISTING SPILLWAYS. SEE EXISTING
FRENCH DRAIN DETAIL ON THIS SHEET.
FOR SPILLWAY PLAN, FOUNDATION AND ANCHOR DETAIL SEE SHEET S503.
FOR WALKWAY DETAILS SEE SHEETS S507 AND S508. FOR WALKWAY
CONCRETE PAD DETAIL SEE SHEET S507. FOR NEW 4' STEEL RISER
SECTION(S) SEE SHEET S501. FOR SPILLWAY GRATING DETAILS SEE
SHEET S506.
1.
2.
3.
4.
5.
THE WALKWAY SUPPORTS SHALL COMPLY WITH THE DETAILS SHOWN ON
SHEETS S507 & S508. LENGTH OF W12 x 65 SHALL BE AS REQUIRED TO FIT
WALKWAY FLUSH WITH THE TOP OF SPILLWAY GRATING.CONTRACTOR
SHALL FURNISH AND INSTALL ADDITIONAL STEEL MEMBERS AS REQUIRED.
DIKE EMBANKMENT BUMP OUT WIDTH AND ELEVATION SHALL BE FIELD
ADJUSTED AS NECESSARY FOR WALKWAY TO SPAN TO THE SPILLWAY
RISER. DIKE EMBANKMENT BUMP OUT TO EXTEND HORIZONTALLY 10' EACH
SIDE OF WALKWAY. MAXIMUM SIDE SLOPES ARE 2H:1V.
ALL MATERIALS REMOVED AND DEMOLISHED SHALL BE DISPOSED OF OFF
OF GOVERNMENT PROPERTY.
6.
7.
8.
N.T.S.
6" TYP.
GEOTEXTILE
2' - 3"
(TYP.)
SW / SP
2" TYP.
4" DIA.
CORRUGATED
PLASTIC
DRAIN
PIPE
NOTES:
PIPING CONSISTS OF 4" PERFORATED CORRUGATED
PLASTIC DRAIN PIPE WITH SOCK SLEEVE UP TO 10'
FROM WHERE DRAIN PIPE DAYLIGHTS OUT OF DIKE
EMBANKMENT.
4" SOLID CORRUGATED PLASTIC DRAIN PIPE
CONNECTS TO THE 4" PERFORATED PLASTIC DRAIN
PIPE AND EXTENDS THROUGH THE EMBANKMENT
10' DOWN SLOPE.
EXISTING FRENCH DRAIN DETAIL
EXISTING SPILLWAYS
30" PIPE
1.
2.
SPILLWAY 1 PROFILE Feet
VERTICAL SCALE 1" = 10'
4020010
Feet
HORIZONTAL SCALE: 1" = 40'
16080040 SOLICITATION NO.:DESIGNED BY:DESCRIPTION1
A MARKSIZE:SUBMITTED BY:DATECONTRACT NO.:CHECKED BY:DRAWN BY:ISSUE DATE:SHEET ID
B
C
D
E
F
G
2 3 4 5 6 7 8 9 10
®
US Army Corps
of Engineers
CELL 1 IMPROVEMENTSEAGLE ISLAND DISPOSAL AREABRUNSWICK COUNTY, NORTH CAROLINAU.S.ARMY CORPS OF ENGINEERSWILMINGTON DISTRICT69 DARLINGTON AVENUEWILMINGTON, NORTH CAROLINA 2840322"X34"S. STELLOJ. MITCHELLDRAWING CODE:WH 104-07-41J. MANNINGSEPTEMBER 2020TBDK. HECKENDORFFILE NAME:95% DQC REVIEW
S101SPILLWAY NO. 1 PROFILE AND NOTESSTA. 151+23.52
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0
10
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50
60
EI21_S101_spillway1_profile.dwg
122+50
-10
0
10
20
30
40
50
60
-10
0
10
20
30
40
50
60
0 50 100 150 200 250 300 3500-50-100-150-200-250-300-350-400-450-500-550
PROPOSED
BUMP OUT
NEW 5'x5'x1.5'
CONC. PAD
NEW GEOTEXTILE
(EL. 35.0)
NEW STEEL WALKWAY
NEW 4' STEEL
RISER SECTIONS
NEW 10'x15'x1'
CONC. PAD
EXISTING
GROUND 2
1
(max.)
NEW 30" OD HDPE PIPE
EL. 20.0'
NEW GEOTEXTILE
NEW 30" OD SDR 11 HDPE PIPE
NEW 4'x8'
STEEL RISER
NEW TIMBER FRAMES
@ 8' MAX. SPANS
SUPPORTING HDPE PIPE
PROPOSED DIKE RAISE
CONNECT NEW HDPE PIPES IN ACCORDANCE
WITH MANUFACTURER'S RECOMMENDATION
CONTRACTOR TO PROVIDE 2' OF CAMBER (NOT SHOWN)STA. -0+33SELECT FILLFILTER SAND
NEW FOUNDATION
SEE SHEET S503 FOR DETAILS
EL. 48.0'
30' MIN
PIPE INVERT MIN. 2' ABOVE
M.H.W (+3.83' NAVD 88)
MAINTAIN MIN.
1' COVER
(EL. 29.0)
171+07.11
-10
0
10
20
30
40
50
60
-10
0
10
20
30
40
50
60
0 50 100 150 200 250 300 3500-50-100-150-200-250-300-350-400-450-500-550
PROPOSED
BUMP OUT
NEW 5'x5'x1.5'
CONC. PAD
NEW GEOTEXTILE
(EL. 34.0)
NEW STEEL WALKWAY
NEW 4' STEEL
RISER SECTIONS
10'x15'x1'
CONC. PAD
EXISTING
GROUND
2
1
(max.)
NEW 30" OD HDPE PIPE
EL. 25.0'
NEW GEOTEXTILE
NEW 30" OD SDR 11 HDPE PIPE
NEW
4'x8' STEEL
RISER
PROPOSED DIKE RAISE
CONNECT NEW HDPE PIPES IN ACCORDANCE
WITH MANUFACTURER'S RECOMMENDATION
CONTRACTOR TO PROVIDE 2' OF CAMBER (NOT SHOWN)STA. -0+16SELECT FILLFILTER SAND
NEW FOUNDATION
SEE SHEET S503 FOR DETAILS
SEE SELECT FILL &
FILTER SAND DETAIL
ON SHEET CN302
(EL. 36.0)
30' MIN
NEW TIMBER FRAMES
@ 8' MAX. SPANS
SUPPORTING HDPE PIPE
PIPE INVERT MIN. 2' ABOVE
M.H.W (+3.83' NAVD 88)
MAINTAIN MIN.
1' COVER
EL. 45.0'
S102SPILLWAYS NO. 2 & NO. 3 PROFILESPILLWAY 3 PROFILE
Feet
HORIZONTAL SCALE: 1" = 40'
16080040
Feet
VERTICAL SCALE: 1" = 10'
4020010 SOLICITATION NO.:DESIGNED BY:DESCRIPTION1
A MARKSIZE:SUBMITTED BY:DATECONTRACT NO.:CHECKED BY:DRAWN BY:ISSUE DATE:SHEET ID
B
C
D
E
F
G
2 3 4 5 6 7 8 9 10
®
US Army Corps
of Engineers
CELL 1 IMPROVEMENTSEAGLE ISLAND DISPOSAL AREABRUNSWICK COUNTY, NORTH CAROLINAU.S.ARMY CORPS OF ENGINEERSWILMINGTON DISTRICT69 DARLINGTON AVENUEWILMINGTON, NORTH CAROLINA 2840322"X34"S. STELLOJ. MITCHELLDRAWING CODE:WH 104-07-41J. MANNINGSEPTEMBER 2020TBDK. HECKENDORFFILE NAME:95% DQC REVIEW
SPILLWAY 2 PROFILE
-10
STA. 122+50
-10
STA. 171+07.11
NOTE: FOR SPILLWAY CONSTRUCTION NOTES SEE SHEET S101.
60
50
40
30
20
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60 EI21_S101_spillway1_profile.dwg
Sp1A - ,.
Imagery: Google Earth 2019

.
Imagery: Goog'le Earth 2019
d
A 1
N
100ft C

Imagery: Google Earth 2019