SW6210903_Plansheet - SCM Detail_20210914

STORMWATER MANAGEMENT NOTES:
1. THE DEVELOPER OR HIS AGENT SHALL CONTACT THE DESIGN ENGINEER WHEN THE
BEST MANAGEMENT PRACTICE(S) ARE CONSTRUCTED AND ABOUT TO BECOME
OPERATIONAL SO A FINAL INSPECTION CAN BE PERFORMED 70 DETERMINE
COMPLIANCE WITH THE APPROVED PLAN CAN BE PERFORMED.
2. ANNUAL MAINTENANCE INSPECTION AND REPORT REQUIRED - THE OWNER OF A
PERMITTED STRUCTURAL STORMWATER BMP/CONTROL SHALL ANNUALLY SUBMIT A
MAINTENANCE AND INSPECTION REPORT FOR EACH BMP TO THE STORMWATER
ADMINISTRATOR. ANNUAL INSPECTIONS SHALL BEGIN WITHIN ONE YEAR OF THE
RECORDATION OF ANY DEED(S) SHOWING STORMWATER BMPs/CONTROL
STRUCTURES.
3, UPON COMPLETION OF THE PROJECT, AND BEFORE A CERTIFICATE OF OCCUPANCY
SHALL BE GRANTED, THE ENGINEER OF RECORD SHALL CERTIFY THAT THE
COMPLETED PROJECT 1S IN ACCORDANCE WITH THE APPROVED STORMWATER
MANAGEMENT PLANS AND DESIGNS.
4. A FINAL INSPECTION OF THE SITE AND STORMWATER MANAGEMENT BMP/CONTROLS
TO BE SCHEDULED WITH AND COMPLETED BY THE PROJECT ENGINEER.
5. NCDEQ AND THEIR ASSIGNS HAVE RIGHT TO ACCESS THE STORMWATER
CONTROL(s) FOR INSPECTIONS OR MAINTENANCE AS NECESSARY.
6. THE ENGINEER'S CERTIFICATION OF COMPLETION WILL BE REQUIRED PRIOR TO THE
FINAL PLAT OR CERTIFICATE OF OCCUPANCY. THE STORMWATER CONTROL IS TO
BE INSPECTED TO ENSURE IT IS FUNCTIONING AS DESIGNED AND HAS FULL
DESIGN VOLUME PRIOR TO ISSUANCE OF THE FINAL CERTIFICATE OF OCCUPANCY.
11, THE PROPERTY OWNER IS RESPONSIBLE FOR MAINTAINING THE STORMWATER
CONTROLS(s) ACCORDING TO THE APPROVED MAINTENANCE PLAN AND DIRECTION
OF NCDEQ.
OPERATION & MAINTENANCE PROVISIONS (INFILTRATION)
e emen :
o en is ro em:
Row io reme is e e ro am
The entire infiltration basin
Trash/debris is present
Remove the trash/debris
The grass filter strip or other pretreatment
Areas of bare soil and/or erosive gullies
Regrade the soil if necessary to remove
area
have formed
the gully, plant ground cover and water
until established. Provide lime and a
one-time fertilizer application
Sediment has accumulated to a depth
Search for the source of the sediment and
greater than three inches
remedy the problem if possible. Remove
the sediment and dispose of It in a
location where it will not cause impacts
to streams or the SCM
The flow diversion structure (if applicable)
The structure is clogged
Unclog the conveyance and dispose of any
sediment in a location where it will not
cause impacts to streams or the SCM
The structure is damaged
Make any necessary repairs or replace if
damage is too much for repair
The inlet device
The inlet pipe is clogged (if applicable)
Unclog the pipe and dispose of any
sediment in a location where it will not
cause impacts to streams or the SCM
The inlet pipe is cracked or otherwise
damaged (if applicable)
Repair or replace the pipe
Erosion is occurring in the Swale
Regrade the swale if necessary and
(if applicable)
provide erosion control devices such as
reinforced turf matting or rip -rap to avoid
future erosion problems
Stone verge is clogged or covered in
sediment (if applicable)
Remove sediment and clogged stone and
replace with clean stone
The basin
More than four inches of sediment has
Search for the source of the sediment and
accumulated
remedy the problem if possible. Remove
the sediment and dispose of it in a
location where it will not cause impacts
to streams or the SCM
Erosion of the basin surface has occurred
Provide additional erosion protection such
or riprop is displaced
as reinforced turf matting or riprop if
needed to prevent future erosion problems
Water is standing more than three days
after a storm event
Replace the top few inches of soil to see
if this corrects the standing water problem.
If not, consult an appropriate professional
for a more extensive repair
The embankment
Shrubs or trees are growing on the
embankment
Remove trees and shrubs immediately
An annual inspection by an appropriate
Make needed repairs immediately
professional shows that the embankment
needs repair
The outlet device
Clogging has occurred
Clean out the outlet device and dispose of
sediment in a location where it will not
cause impacts to streams or the SCM
The outlet device is damaged
Repair or replace the outlet device
The receiving water
Erosion or other signs of damage have
Repair the damage and improve the flow
occurred at the outlet
dissipation structure
Discharges from the infiltration trench are
causing erosion or sedimentation in the
Contact the local NCDEQ Regional Office
receiving water
rOPERATION AND MAINTENANCE
North Carolina storm water rules require quarterly inspections by the regulating agency of infiltration areas as a minimum. More
frequent inspections by the land owner or system operator are strongly encouraged to ensure the proper operation of infiltration
areas.
A. Rainfall Event
1. Inspect the basin after every rainfall event greater than 1.5 inches.
B. Monthly Inspection
1. Inspect the basin monthly
2. Check the infiltration area side slopes; remove trash and repair eroded areas before the next rainfall event.
3. Check the vegetative and rock filters for sediment accumulation, erosion and proper operation of the flow spreader
mechanism and repair as necessary.
C. Quarterly Inspection
1. Inspect the collection system (i.e. catch basin, pipes and grass swales) for proper functioning. Clear accumulated
trash from basin grates and basin bottoms. Check piping for obstructions.
2. Check pond inlet pipes for undercutting, replace rip -rap and repair broken pipes.
3. Reseed grassed swales, including the vegetated filter if applicable, twice a year as necessary. Repair eroded areas
immediately.
D. Six Month Inspection
1. Remove accumulated sediment from the bottom of the outlet structure or other areas where accumulated sediment is
noted.
2. Inspect the embankment taking note of any wet areas where water may be seeping through the soil.
E. General Inspection
1. Maximum grass height is to be 61n.
2. No woody vegetation shall be allowed to grow in the infiltration area.
3. Debris shall be removed from blocking the inlet and outlet structures and from areas of potential clogging.
4. Periodic removal of dead vegetation shall be accomplished.
5. All components of the infiltration system must be kept in good working order.
kSS SOD NOTE:
S SOD SHALL BE EITHER HYBRID BERMUDA GRASS OR CENTIPEDE THAT HAS BEEN GROWN IN A SOIL
IS FREE OF AN IMPERMEABLE LAYER (SUCH AS CLAY).
NOTES:
1. ALL INFILTRATION BASINS SHALL HAVE AN ACCESS EASEMENT CONNECTING TO A DEDICATED PUBLIC RIGHT OF WAY.
2. ALL DRAINAGE AREAS TO AN INFILTRATION BASIN ARE TO BE STABILIZED PRIOR TO INSTALLATION OF SOILS OR GRASS SOD.
3. THE DRAINAGE AREA OF THE INFILTRATION BASIN WILL BE CAREFULLY MANAGED TO REDUCE THE SEDIMENT LOAD TO THE SAND FILTER SYSTEM.
4. THE WATER LEVEL IN THE MONITORING WELL(S) WILL BE RECORDED ONCE A MONTH AND AFTER EVERY STORM EVENT GREATER THAN 1.5 INCHES.
5. IMMEDIATELY AFTER THE INFILTRATION BASIN IS ESTABLISHED, THE VEGETATION WILL BE WATERED TWICE WEEKLY IF NEEDED UNTIL PLANTS BECOME
ESTABLISHED (COMMONLY SIX WEEKS)
6. NO PORTION OF THE INFILTRATION BASIN WILL BE FERTILIZED AFTER THE INITIAL FERTILIZATION THAT IS REQUIRED TO ESTABLISH THE VEGETATION.
7. THE VEGETATION IN AND AROUND THE BASIN WILL BE MAINTAINED AT A HEIGHT OF APPROXIMATELY SIX INCHES.
EXISTING GRADE = 340.0
TOP OF EMBANKMENT = 340.0
1 STORMWATER MANAGEMENT DETAILS
NOT TO SCALE
N
RIP -RAP PRE-TREATMENT
FOREBAY AT PIPE INLETS
SEE DETAIL THIS SHEET
FILTER FABRIC
INFILTRATION BASIN TYPICAL SECTION
NTS
\
STORMWATER
/ a MANAGEMENT
EASEMENT
\ t _ GRASS SPILLWAY -
\ REFER TO DETAIL
/ r \ THIS SHEET
\
I \ k lJ e \
- _ _ - MANAGEMENT
_ _ -- / / '`� TOP OF EMBANKMENT \ \ �. _ STORMWATER
_ ELEV=340.0 0 �` \ ° \ \ ` \ 1 o EASEMENT
r. a
r
"Dc'
If
OBSERVATION WELL ✓ --' ��\ / , / /
\,,\
r /
two / / / �✓/ ���\� ��/ //
/ 141
\
I `• I / STORMWATER
MANAGEMENT I / _ ,®�1• /`' \ \� / J /S \\ \ -' l
I I - --
EASEMENT / / I I \ NL
If
It
PLAN VIEW
REMOVABLE CAP
6" SCHEDULE 40
PVC, SDR35, OR SMOOTH WALL
CORRUGATED PLASTIC
PIPE WITH 3/8" PERFORATIONS
0 6" ON CENTER
(4 HOLES PER ROW)
FLUSH WITH
PAVEMENT IN
PERMEABLE PAVEMENT
AREAS
r
0
0 0
o
a o
z
a
_
0 0
o
0 0
a
°
W
INFILTRATION
.
° a
SAND MEDIA
h
o.
0 0
�
a
o
0 0
a
°
o o
o
a
0 o
o
�
a a
0
0 0
0
0 0
o°o
UNDISTURBED SUBSOIL
INSERT
4"-6" INTO
IN -SITU
SOIL BASE
OBSERVATION
WELL
N.T.S.
SCALE:
STORM DRAINAGE PIPE
OR CONCRETE FL
OUTFACE INTO POND LENGTH 8c WIDTH
DIMENSIONS TO BE
PER RIP -RAP
- ' APRON DETAIL
.T - ;,- -- TAPER DEPTH
O
'i
-Tr rTf _ I FOREBAY 1'
2'
SILT FENCE AS NEEDED
FILTER BED
L��l'/�ILIi
BIO-RETENTION POND
a a'o 0 0
•°qf On440o �
6" CLASS B
RIP -RAP OVER
RIP -RAP FOREBAY FILTER FABRIC
SCALE: N.T.S.
MEDIA (SEE NOTE 2)
LEVEL
NOTE: 11 I
1 • PRIOR TO INSTALLATION, MANUFACTURER SPECIFICATIONS OF FILTER MEDIA SHALL
BE REVIEWED TO ENSURE THAT DISCHARGE FROM FILTER MEDIA SHALL MEET OR
EXCEED THE PROVISIONS OF THE CLEAN WATER ACT.
2. ENSURE THAT PUMP PRESSURE DOES NOT EXCEED FILTER MEDIA PRESSURE RATING.
3. FILTER MEDIA MAY BE, BUT NOT LIMITED TO, SAND MEDIA FILTRATION DEVICES,
RATED FILTER FABRIC BAGS OR POLYMER BASED DEWATERING PRACTICES.
T
4. PUMP STRAINER SHALL NOT BE IN CONTACT WITH BOTTOM OF POND. \Aq_
INFILTRATION BASIN DEWATERING LOW POINT
FLOW LONG.. SS CHANNEL LINING TOP OF EMBANKMENT SPILLWAY ELEVATION
SPILLWAY Q(100) SLOPE(%) H B W ELEVATION
W
EXTEND LINING TO EXTEND LINING TO
TOP OF SPILLWAY SPILLWAY
TOP OF
TOP OF EMBANK MENT=340.0
ss H
CHANNEL LINING
SPILLWAY ELEVATION=338.1
MATTING SHALL BE AS
NOTED OR APPROVED EQUAL.
B
GRASS SPILLWAY DETAIL
GRASS SOD ON SPILLWAY
AND SIDE
SLOPES
STAGE STORAGE TABLE
INFILTRATION BASIN
STAGE ELEVATION CONTOUR
INCREMENTAL
TOTAL
(FT) (FT) AREA (SF)
STORAGE
(CFZ STORAGE (CF)
0.0 333.0 27255
0
0
1.0 334.0 29505
28380
28380
2.0 335.0 31810
30658
59038
3.0 336.0 34170
32990
92028
4.0 337.0 36585
35378
127405
5.0 338.0 39060
37823
165228
6.0 339.0 41595
40328
205555
7.0 340.0 44180
42888
248443
STORMWATER MANAGEMENT DESIGN
INFILTRATION BASIN
RIVER BASIN: LUMBER
RECEIVING STREAM: LITTLE CREEK
STREAM INDEX: 14-2-17
STREAM CLASS: C
HUC: 03040203
POND DESIGN SUMMARY
DRAINAGE AREA TO POND:
34.53 ACRES
SITE IMPERVIOUS AREA TO POND:
9.07 ACRES
OFF -SITE DESIGN IMPERVIOUS AREA TO POND:
0.00 ACRES
TOTAL DESIGN IMPERVIOUS AREA TO POND:
9.07 ACRES
PRE -DEVELOPED
POST -DEVELOPED POST DEVELOPED
THROUGH POND
DRAINAGE AREA: 34.53 AC
34.53 AC
CURVE NUMBER: 57.0
70.3
INFILTRATION RATE:
4.0 IN/HR
1.0" STORM EVENT:
0.155 CFS
0.000 CFS
GRAPHIC SCALE
1-YEAR STORM EVENT: 3.625 CFS
43.35 CFS
0.000 CFS
30 0 15
30
2-YEAR STORM EVENT: 10.35 CFS
67,34 CFS
0.000 CFS
10-YEAR STORM EVENT: 39.93 CFS
140.83 CFS
0.000 CFS
100-YEAR STORM EVENT: 104.08 CFS
273.59 CFS
- 127.33 CFS
1 INCH = 30 FEET
SIM
Z
C�
Cie
W
CONSULTANT:
Triangle Site Design, PLLC
4004 Barrett Drive
Suite 101
Raleigh, NC 27609
[phone]
mlowder®trionglesitedesign.com
NC License #P-0619
®O.' EE5S7o ' i'I'':
® SEAL
051571
°'1sis��eo°• .�
OWNER/DEVELOPER:
Lee Humphrey
Double D Engineering, PLLC
150 S. Page Street
Southern Pines, NC 28387
910-684-8646 (Office)
9.10-206-1808 (cell)
lee®doubledeng.com
I�
CD
C)
L_+_J
This document, together with
the concepts and designs
presented herein, as an
instrument of services, is
intended only for the specific
purpose and client for which
it was prepared. Reuse of
and improper reliance on this
document without written
authorization and adaptation
by Triangle Site Design, PLLC
shall be without liability to
Triangle Site Design, PLLC.
Drawn
Checked
Approved
Project No: 048017
Date: September 7, 2021
Title
STORMWATER
CONTROL
MEASURE DETAILS
Sheet No.
S C M
INFILTRATION
127.33 CFS
3.33
1.9
30
�
41.4
3:1
STRAW WITH NET
340.0
338.10
SPILLWAY
NAG SHOREMAX
CLASS C W� P550