20071353 Ver 2_More Info Received_20080915

WITHERS RAVENEL
ENGINEERS I PLANNERS 1 SURVEYORS
September 15, 2oo8
Ms. Annette Lucas
Department of Environment and Natural Resources
Division of Water Quality
2321 Crabtree Boulevard, Suite 250
Raleigh, NC 27604
Re: Avon Forest Subdivision - Nash County, NC
DWQ Project # 07-1353
W&R Project # 02070757.0
Dear Ms. Lucas:
If11 ??
SEP 15 2008
UENR - WATER Q
Wr. -ANDS ANDSTORAI A
Please find attached five (5) sets of revised construction plans and supporting documents for the
above-referenced project. This package is submitted in response to your letter requesting additional
information dated June 5, 2oo8. The plans have been revised in accordance with direction received
during our review meeting with you on July 23, 2oo8. The items listed in your letter have been
addressed as follows:
1. The previously-shown filter strip and level spreader on lot 7 have been replaced with a
bioretention cell as discussed in our meeting. The bioretention supplement forms and 0&M
documents are included with this submittal.
Per our meeting, additional measures are not required at required at FES-5, FES-6, FES-13 and
the ditch between lots 31 & 32 since those areas are not adjacent to riparian buffers. A level
spreader has been added on lot 37 near FES-3 in orderto provide diffuse flow of the runoff from
the roadside ditch at the north side of that crossing. Since the topography on lot 36 does not
support a level spreader, the runoff from that area is now being piped across the street to lot 28
where a level spreader is provided. As discussed in our meeting, Zone 2 of the riparian buffer
at both of those locations is being graded so as to conform to the maximum slope
requirements. The associated supplement forms and 0&M documents are included with this
submittal.
Should you have any questions about these revisions or require any additional information, please give
me a call at 919-469-3340•
Sincerely,
WITHERS & RAVENEL, INC.
Brad Hart, PE
Cc: Mike Jolley - Calnat, LLC
iii MacKenan Drive Cary, North Carolina 27511 tel:[phone] fax:[phone]oo8 www.withersravenet.com
Permit Number: 0 1 - 13 S 3
(to be provided by DWQ)
Drainage Area Number: LOT 7
Bioretention Operation and Maintenance Agreement
I will keep a maintenance record on this BMP. This maintenance record will be kept in a
log in a known set location. Any deficient BMP elements noted in the inspection will be
corrected, repaired or replaced immediately. These deficiencies can affect the integrity
of structures, safety of the public, and the removal efficiency of the BMP.
Important operation and maintenance procedures:
- Immediately after the bioretention cell is established, the plants will be watered
twice weekly if needed until the plants become established (commonly six
weeks).
- Snow, mulch or any other material will NEVER be piled on the surface of the
bioretention cell.
- Heavy equipment will NEVER be driven over the bioretention cell.
- Special care will be taken to prevent sediment from entering the bioretention cell.
- Once a year, a soil test of the soil media will be conducted.
After the bioretention cell is established, I will inspect it once a month and within 24
hours after every storm event greater than 1.0 inches (or 1.5 inches if in a Coastal
County). Records of operation and maintenance will be kept in a known set location
and will be available upon request.
Inspection activities shall be performed as follows. Any problems that are found shall
be repaired immediately.
BMP element: Potential problems: How I will remediate the problem:
The entire BMP Trash/debris is resent. Remove the trash/ debris.
The perimeter of the Areas of bare soil and/or Regrade the soil if necessary to
bioretention cell erosive gullies have formed. remove the gully, and then plant a
ground cover and water until it is
established. Provide lime and a
one-time fertilizer application.
The inlet device: pipe, The pipe is clogged (if Unclog the pipe. Dispose of the
stone verge or Swale applicable). sediment off-site.
The pipe is cracked or Replace the pipe.
otherwise damaged (if
applicable).
Erosion is occurring in the Regrade the swale if necessary to
swale (if applicable). smooth it over and provide erosion
control devices such as reinforced
turf matting or riprap to avoid
future problems with erosion.
Stone verge is clogged or Remove sediment and clogged
covered in sediment (if stone and replace with clean stone.
a licable .
Form SW401-Bioretention O&M-Rev.3 Page 1 of 4
BMP element: Potential problems: How I will remediate the problem:
The pretreatment area Flow is bypassing Regrade if necessary to route all
pretreatment area and/or flow to the pretreatment area.
gullies have formed. Restabilize the area after grading.
Sediment has accumulated to Search for the source of the
a depth greater than three sediment and remedy the problem if
inches. possible. Remove the sediment and
restabilize the pretreatment area.
Erosion has occurred. Provide additional erosion
protection such as reinforced turf
matting or riprap if needed to
prevent future erosion problems.
Weeds are present. Remove the weeds, preferably by
hand.
The bioretention cell: Best professional practices Prune according to best professional
vegetation show that pruning is needed practices.
to maintain optimal plant
health.
Plants are dead, diseased or Determine the source of the
dying. problem: soils, hydrology, disease,
etc. Remedy the problem and
replace plants. Provide a one-time
fertilizer application to establish the
ground cover if a soil test indicates
it is necessary.
Tree stakes/wires are present Remove tree stake/ wires (which
six months after planting. can kill the tree if not removed).
The bioretention cell: Mulch is breaking down or Spot mulch if there are only random
soils and mulch has floated away. void areas. Replace whole mulch
layer if necessary. Remove the
remaining much and replace with
triple shredded hard wood mulch at
a maximum depth of three inches.
Soils and/or mulch are Determine the extent of the clogging
clogged with sediment. - remove and replace either just the
top layers or the entire media as
needed. Dispose of the spoil in an
appropriate off-site location. Use
triple shredded hard wood mulch at
a maximum depth of three inches.
Search for the source of the
sediment and remedy the problem if
possible.
An annual soil test shows that Dolomitic lime shall be applied as
pH has dropped or heavy recommended per the soil test and
metals have accumulated in toxic soils shall be removed,
the soil media. disposed of properly and replaced
with new planting media.
Form SW401-Bioretention O&M-Rev.3 Page 2 of 4
BMP element: Potential problems: How I will remediate the problem:
The underdrain system Clogging has occurred. Wash out the underdrain system.
(if applicable)
The drop inlet Clogging has occurred. Clean out the drop inlet. Dispose of
the sediment off-site.
The drop inlet is damaged Repair or replace the drop inlet.
The receiving water Erosion or other signs of Contact the NC Division of Water
damage have occurred at the Quality 401 Oversight Unit at 919-
outlet. 733-1786.
Form SW401-Bioretention O&M-Rev. 3 Page 3 of 4
Permit Number:
(to be provided by DWQ)
I acknowledge and agree by my signature below that I am responsible for the
performance of the maintenance procedures listed above. I agree to notify DWQ of any
problems with the system or prior to any changes to the system or responsible party.
Project name: Avon Forest (Nash County, NC)
BMP drainage area number:
Print name: Michael D. Jolley
Title: Managing Member Calnat LLC
Address: 3408 Corsham Drive Apex NC 27539
Phone: [phone]
Signature:
Date: `7 112- u b U
Note: The legally responsible party should not be a homeowners association unless more than 50% of
the lots have been sold and a resident of the subdivision has been named the president.
I, KC,'? 4Z, M ?-A_ , a Notary Public for the State of
Noon Cc,_roV n&, , County of do hereby certify that
k-A i Unae y 'b. Jol\.ty personally appeared before me this 12-
day of SQplf-mbcr , 21:)o ?5' , and acknowledge the due execution of the
forgoing bioretention maintenance requirements. Witness my hand and official seal,
` •(IE MEZ ''%
y•.
9' . pUBOG
%FC OUL
SEAL
r^
My commission expires orb 2161 Form SW401-Bioretention I&M-Rev. 2

Page 4 of 4
Permit Number: D7- 1.3 5 3
(to be provided by DWQ)
Drainage Area Number: L.&-r 28
Filter Strip, Restored Riparian Buffer and Level Spreader
Operation and Maintenance Agreement
I will keep a maintenance record on this BMP. This maintenance record will be kept in a
log in a known set location. Any deficient BMP elements noted in the inspection will be
corrected, repaired or replaced immediately. These deficiencies can affect the integrity
of structures, safety of the public, and the removal efficiency of the BMP.
Important maintenance procedures:
- Immediately after the filter strip is established, any newly planted vegetation
will be watered twice weekly if needed until the plants become established
(commonly six weeks).
- Once a year, the filter strip will be reseeded to maintain a dense growth of
vegetation
- Stable groundcover will be maintained in the drainage area to reduce the
sediment load to the vegetation.
- Two to three times a year, grass filter strips will be mowed and the clippings
harvested to promote the growth of thick vegetation with optimum pollutant
removal efficiency. Turf grass should not be cut shorter than 3 to 5 inches and
may be allowed to grow as tall as 12 inches depending on aesthetic requirements
(NIPC,1993). Forested filter strips do not require this type of maintenance.
- Once a year, the soil will be aerated if necessary.
- Once a year, soil pH will be tested and lime will be added if necessary.
After the filter strip is established, it will be inspected quarterly and within 24 hours
after every storm event greater than 1.0 inch (or 1.5 inches if in a Coastal County).
Records of operation and maintenance will be kept in a known set location and will be
available upon request.
Inspection activities shall be performed as follows. Any problems that are found shall
be repaired immediately.
BMP element: Potential problem: How I will remediate the problem:
The entire filter strip Trash/ debris is present. Remove the trash/debris.
system
The flow splitter device The flow sputter device is Unclog the conveyance and dispose
(if applicable) clogged. of an sediment off-site.
The flow sputter device is Make any necessary repairs or
damaged. replace if damage is too large for
repair.
Form SWU401-Level Spreader, Filter Strip, Restored Riparian Buffer O&M-Rev.3 Page 1 of 3
BMP element: Potential problem: How I will remediate the problem:
The swale and the level The swale is clogged with Remove the sediment and dispose
lip sediment. of it off-site.
The level lip is cracked, Repair or replace lip.
settled, undercut, eroded or
otherwise damaged.
There is erosion around the Regrade the soil to create a berm
end of the level spreader that that is higher than the level lip, and
shows stormwater has then plant a ground cover and
bypassed it. water until it is established. Provide
lime and a one-time fertilizer
application.
Trees or shrubs have begun Remove them.
to grow on the swale or just
downslo a of the level lip.
The bypass channel Areas of bare soil and/or Regrade the soil if necessary to
erosive gullies have formed. remove the gully, and then
reestablish proper erosion control.
Turf reinforcement is Study the site to see if a larger
damaged or ripap is rolling bypass channel is needed (enlarge if
downhill. necessary). After this, reestablish
the erosion control material.
The filter strip Grass is too short or too long Maintain grass at a height of
if applicable). approximately three to six inches.
Areas of bare soil and/or Regrade the soil if necessary to
erosive gullies have formed. remove the gully, and then plant a
ground cover and water until it is
established. Provide lime and a
one-time fertilizer application.
Sediment is building up on Remove the sediment and
the filter strip. restabilize the soil with vegetation if
necessary. Provide lime and a one-
time fertilizer application.
Plants are desiccated. Provide additional irrigation and
fertilizer as needed.
Plants are dead, diseased or Determine the source of the
dying. problem: soils, hydrology, disease,
etc. Remedy the problem and
replace plants. Provide a one-time
fertilizer application.
Nuisance vegetation is Remove vegetation by hand if
choking out desirable species. possible. If pesticide is used, do not
allow it to get into the receiving
water.
The receiving water Erosion or other signs of Contact the NC Division of Water
damage have occurred at the Quality local Regional Office, or the
outlet. 401 Oversight Unit at 919-733-1786.
Form SWU401-Level Spreader, Filter Strip, Restored Riparian Buffer O&M-Rev.3 Page 2 of 3
Permit Number:
(to be provided by DWQ)
I acknowledge and agree by my signature below that I am responsible for the
performance of the maintenance procedures listed above. I agree to notify DWQ of any
problems with the system or prior to any changes to the system or responsible party.
Project name: Avon Forest (Nash County, NCB
BMP drainage area number:
Print name: Michael D. Jolley
Title: Managing Member, Calnat, LLC
Address: 3408 Corsham Drive, Apex, NC 27539
Phone: [phone] ,
Signature:
Date: 1? 114, -,'IQ
Note: The legally responsible party should not be a homeowners association unless more than 50% of
the lots have been sold and a resident of the subdivision has been named the president.
I, K k1 i k- me -y k , a Notary Public for the State of
o rk \ Cra,rDLi(lck- , County of W oLV_ , do hereby certify that
?Llxcle'A 1? . ?a\\ ?? 1 personally appeared before me this Z
day of deg ?em6cr Zv ou- , and acknowledge the due execution of the
forgoing filter strip, riparian buffer, and/or level spreader maintenance requirements.
Witness my hand and official seal,
II111/////
MEL/
.?pTARy'
SEAL
My commission expires 10 , Zola
T
Form SWU401-Level Spreader, Filter Strip, Restored Riparian Buffer O&M-Rev.3 Page 3 of 3
Permit Number: 01 - 1353
(to be provided by DWQ)
Drainage Area Number: L017'$7
Filter Strip, Restored Riparian Buffer and Level Spreader
Operation and Maintenance Agreement
I will keep a maintenance record on this BMP. This maintenance record will be kept in a
log in a known set location. Any deficient BMP elements noted in the inspection will be
corrected, repaired or replaced immediately. These deficiencies can affect the integrity
of structures, safety of the public, and the removal efficiency of the BMP.
Important maintenance procedures:
- Immediately after the filter strip is established, any newly planted vegetation
will be watered twice weekly if needed until the plants become established
(commonly six weeks).
- Once a year, the filter strip will be reseeded to maintain a dense growth of
vegetation
- Stable groundcover will be maintained in the drainage area to reduce the
sediment load to the vegetation.
- Two to three times a year, grass filter strips will be mowed and the clippings
harvested to promote the growth of thick vegetation with optimum pollutant
removal efficiency. Turf grass should not be cut shorter than 3 to 5 inches and
may be allowed to grow as tall as 12 inches depending on aesthetic requirements
(NIPC,1993). Forested filter strips do not require this type of maintenance.
- Once a year, the soil will be aerated if necessary.
- Once a year, soil pH will be tested and lime will be added if necessary.
After the filter strip is established, it will be inspected quarterly and within 24 hours
after every storm event greater than 1.0 inch (or 1.5 inches if in a Coastal County).
Records of operation and maintenance will be kept in a known set location and will be
available upon request.
Inspection activities shall be performed as follows. Any problems that are found shall
be repaired immediately.
BMP element: Potential problem: How I will remediate the problem:
The entire filter strip Trash/debris is present. Remove the trash/ debris.
system
The flow splitter device The flow splitter device is Unclog the conveyance and dispose
(if applicable) clogged. of an sediment off-site.
The flow splitter device is Make any necessary repairs or
damaged. replace if damage is too large for
repair.
Form SWU401-Level Spreader, Filter Strip, Restored Riparian Buffer O&M-Rev.3 Page 1 of 3
BMP element: Potential problem: How I will remediate the problem:
The swale and the level The swale is clogged with Remove the sediment and dispose
lip sediment. of it off-site.
The level lip is cracked, Repair or replace lip.
settled, undercut, eroded or
otherwise damaged.
There is erosion around the Regrade the soil to create a berm
end of the level spreader that that is higher than the level lip, and
shows stormwater has then plant a ground cover and
bypassed it. water until it is established. Provide
lime and a one-time fertilizer
application.
Trees or shrubs have begun Remove them.
to grow on the swale or just
downslo e of the level lip.
The bypass channel Areas of bare soil and/or Regrade the soil if necessary to
erosive gullies have formed. remove the gully, and then
reestablish proper erosion control.
Turf reinforcement is Study the site to see if a larger
damaged or ripap is rolling bypass channel is needed (enlarge if
downhill. necessary). After this, reestablish
the erosion control material.
The filter strip Grass is too short or too long Maintain grass at a height of
if applicable). approximately three to six inches.
Areas of bare soil and/or Regrade the soil if necessary to
erosive gullies have formed. remove the gully, and then plant a
ground cover and water until it is
established. Provide lime and a
one-time fertilizer application.
Sediment is building up on Remove the sediment and
the filter strip. restabilize the soil with vegetation if
necessary. Provide lime and a one-
time fertilizer application.
Plants are desiccated. Provide additional irrigation and
fertilizer as needed.
Plants are dead, diseased or Determine the source of the
dying. problem: soils, hydrology, disease,
etc. Remedy the problem and
replace plants. Provide a one-time
fertilizer application.
Nuisance vegetation is Remove vegetation by hand if
choking out desirable species. possible. If pesticide is used, do not
allow it to get into the receiving
water.
The receiving water Erosion or other signs of Contact the NC Division of Water
damage have occurred at the Quality local Regional Office, or the
outlet. 401 Oversight Unit at 919-733-1786.
Form SWU401-Level Spreader, Filter Strip, Restored Riparian Buffer O&M-Rev.3 Page 2 of 3
Permit Number:
(to be provided by DwQ)
I acknowledge and agree by my signature below that I am responsible for the
performance of the maintenance procedures listed above. I agree to notify DWQ of any
problems with the system or prior to any changes to the system or responsible party.
Project name: Avon Forest (Nash Count)
BMP drainage area number:
Print name: Michael D. Jolley
Title: Managing Member, Calnat, LLC
Address: 3408 Corsham Drive, Apex, NC 27539
Phone: 919-369-I6A328
Signature:
Date: `l
Note: The legally responsible party should not be a homeowners association unless more than 50% of
the lots have been sold and a resident of the subdivision has been named the president.
I, a Notary Public for the State of
County of do hereby certify that
m? (.h?,? ?? J \\t? personally appeared before me this. 12-
day of Sx_p\t. \Ckr Zoo g , and acknowledge the due execution of the
forgoing filter strip, riparian buffer, and/or level spreader maintenance requirements.
Witness my hand and official seal,
?OTAgy• ;
PUBL?G :'c,•
lilt ,IIA%%
SEAL
My commission expires
Form SWU401-Level Spreader, Filter Strip, Restored Riparian Buffer O&M-Rev.3 Page 3 of 3
AM
HCDENR
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
BIORETENTION CELL SUPPLEMENT
Permit Number: E) 1 - 1353
(to be provided by DWQ)
O?OF W ATE9OG
O c
This form must be filled out, printed and submitted.
The Required Items Checklist (Part III) must be printed, filled out and submitted along with all of the required information.
I. PROJECT INFORMATION
Project name Avon Forest (Nash County, NC)
Contact name Brad Hart, PE
Phone number 919-469-3340
Date September 10, 2008
Drainage area number Lot 7
II. DESIGN INFORMATION
Site Characteristics
Drainage area 92,783.00 ft2
Impervious area 25,700.00 ft2
Percent impervious 27.7% %
Design rainfall depth 1.00 inch
Peak Flow Calculations
1-yr, 24-hr runoff depth 2.68 in
1-yr, 24-hr intensity 0.11 in/hr
Pre-development 1-yr, 24-hr peak flow 1.99 ft3/sec
Post-development 1-yr, 24-hr peak flow 4.57 ft3/sec
Pre/Post 1-yr, 24-hr peak control 2.58 ft3/sec
Storage Volume: Non-SR Waters
Design volume 3,100.00 ft3
Storage Volume: SR Waters
Pre-development 1-yr, 24-hr runoff ft3
Post-development 1-yr, 24-hr runoff ft3
Minimum volume required 0.00 ft3
Volume provided ft3
Cell Dimensions
Ponding depth of water 12.00 inches OK
Ponding depth of water 1.00 ft
Surface area of the top of the bioretention cell 3627.00 ft2 OK
Length: 102.20 ft OK
Width: 35.50 ft OK
-or- Radius ft
Soils Report Summary
Drawdown time, ponded volume 12.00 hr OK
Drawdown time, to 24 inches below surface 0.00 hr OK
Drawdown time, total: 12.00 hr
In-situ soil:
Soil permeability 0.52 in/hr OK
Planting media soil:
Soil permeability 0.52 in/hr OK
Soil composition
% Sand (by weight) 86% OK
% Fines (by weight) 10% OK
% Organic (by weight) 4% OK
Total: 100%
Form SW401-Bioretention-Rev.3 Parts I and II. Design Summary, Page 1 of 2
Permit Number:
(to be provided by DWQ)
Phosphorus Index (P-Index)
Basin Elevations
Temporary pool elevation
Planting elevation (top of the mulch)
Bottom of the cell
Planting depth
Depth of mulch
SHWT elevation
Are underdrains being installed?
How many clean out pipes are being installed?
What factor of safety is used for sizing the underdrains? (See
BMP Manual Section 12.3.6)
Additional distance between the bottom of the planting media and
the bottom of the cell to account for underdrains
Bottom of the cell required
Distance from bottom to SHWT
Type of bioretention cell (answer "Y" to only one of the two
following questions):
Is this a grassed cell?
Is this a cell with trees/shrubs?
Planting Plan
Number of tree species
Number of shrub species
Number of herbaceous groundcover species
Additional Information
Does volume in excess of the design volume bypass the
bioretention cell?
Does volume in excess of the design volume flow evenly distributed
through a vegetated filter?
What is the length of the vegetated filter?
Does the design use a level spreader to evenly distribute flow?
Is the BMP located at least 30 feet from surface waters (50 feet if
SA waters)?
Is the BMP located at least 100 feet from water supply wells?
Are the vegetated side slopes equal to or less than 3:1?
Is the BMP located in a recorded drainage easement with a
recorded access easement to a public Right of Way (ROW)?
Inlet velocity (from treatment system)
Is the area surrounding the cell likely to undergo development in
the future?
Are the slopes draining to the bioretention cell greater than 20%?
Is the drainage area permanently stabilized?
Pretreatment Used
(Indicate Type Used with an "X" in the shaded cell)
Gravel and grass
(8'inches gravel followed by 3-5 ft of grass)
Grassed Swale
Forebay
20 (unitless) OK
254.00 fmsl
253.00 fmsl OK
251.00 fmsl
2.00 ft
4.00 inches OK
247.00 fmsl OK
Y (Y or N)
6 OK
5.00 OK
1ft
250.00 fmsl
3.00 ft OK
Y (Y or N) OK
N (Y or N)
0 More species are recommended.
0 More species are recommended.
0 More species are recommended.
Y (Y or N) OK
N (Y or N) Excess volume must pass through filter.
IWH TI
N (Y or N) Show how flow is evenly distributed.
Y (Y or N) OK
Y (Y or N) OK
Y (Y or N) OK
Y (Y or N) OK
5.27 fUsec Insufficient inlet velocity unless energy dissipating devices are
being used.
N (Y or N) OK
N (Y or N) OK
Y (Y or N) OK
Form SW401-Bioretention-Rev.3 Parts I and 11. Design Summary, Page 2 of 2
Permit No:
(to be assigned by DWQ)
III. REQUIRED ITEMS CHECKLIST
Please indicate the page or plan sheet numbers where the supporting documentation can be found. An incomplete submittal package will
result in a request for additional information. This will delay final review and approval of the project. Initial in the space provided to
indicate the following design requirements have been met. If the applicant has designated an agent, the agent may initial below. If a
requirement has not been met, attach justification.
Pagel Plan
Initial Sheet No.
44- V ir5
Slf.to" I
i0.1
_0- 10.1

_44- t')Ik
(0.
? lQ-I
N/?+
Plans (1" - 50' or larger) of the entire site showing:
Design at ultimate build-out,
Off-site drainage (if applicable),
Delineated drainage basins (include Rational C coefficient per basin),
Cell dimensions,
Pretreatment system,
High flow bypass system,
Maintenance access,
Proposed drainage easement and public right of way (ROW),
Clean out pipe locations,
Overflow device, and
Boundaries of drainage easement.
Plan details (1" = 30' or larger) for the bioretention cell showing:
Cell dimensions
Pretreatment system,
High flow bypass system,
Maintenance access,
Recorded drainage easement and public right of way (ROW),
Design at ultimate build-out,
Off-site drainage (if applicable),
Clean out pipe locations,
Overflow device, and
Boundaries of drainage easement.
3. Section view of the bioretention cell (1" = 20' or larger) showing:
Side slopes, 3:1 or lower
Underdrain system (if applicable), and
Bioretention cell layers [ground level and slope, pre-treatment, ponding depth, mulch depth, fill media
depth, washed sand, filter fabric (or choking stone if applicable), #57 stone, underdrains (if applicable),
SHWT level(s), and overflow structure]
4. A soils report that is based upon an actual field investigation, soil borings, and infiltration tests. The
results of the soils report must be verified in the field by DWQ, by completing & submitting the soils
investigation request form. County soil maps are not an acceptable source of soils information. All
elevations shall be in feet mean sea level (fmsl). Results of soils tests of both the planting soil and the in
situ soil must include:
Soil permeability, EK9 inea?'ai S4(ec4- 6- c4411
Soil composition (% sand, % fines, % organic), and M 4_4Vta(,S 5i ec?4W e ^ r La.
P-index.
5. A detailed planting plan (1" = 20' or larger) prepared by a qualified individual showing:
A variety of suitable species,
Sizes, spacing and locations of plantings,
Total quantity of each type of plant specified,
A planting detail,
The source nursery for the plants, and
Fertilizer and watering requirements to establish vegetation.
6. A construction sequence that shows how the bioretention cell will be protected from sediment until the
entire drainage area is stabilized.
7. The supporting calculations (including underdrain calculations, if applicable).
8. A copy of the signed and notarized operation and maintenance (0&M) agreement.
9. A copy of the deed restrictions (if required).
Form SW401-Bioretention-Rev.3 Part 111, Page 1 of 1
of-t3S3
A=*A
NCDENR
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>IIJWLJI'?
OIiii? r
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
LEVEL SPREADER, FILTER STRIP AND RESTORED RIPARIAN BUFFER SUPPLEMENT
This form must be completely filled out, printed and submitted.
DO NOT FORGET TO ATTACH THE REQUIRED ITEMS CHECKLIST AND ALL REQUIRED ITEMS (NEXT WORKSHEET)!
I. PROJECT INFORMATION
Project name Avon Forest (Nash County, NC)
Contact name Brad Hart, PE
Phone number 919469-3340
Date August 7, 2008
Drainage area number Lot 28
II. DESIGN INFORMATION
For Level Spreaders Receiving Flow From a BMP
Type of BMP N/A
Drawdown flow from the BMP cfs
For Level Spreaders Receiving Flow from the Drainage Area
Drainage area
Impervious surface area
Percent impervious
Rational C coefficient
Peak flow from the 1 in/hr storm
Time of concentration
Rainfall intensity, 10-yr storm
Peak flow from the 10-yr storm
Where Does the Level Spreader Discharge ?
To a grassed bioretention cell?
To a mulched bioretention cell?
To a wetland?
To a filter strip or riparian buffer?
Other (specify)
Filter Strip or Riparian Buffer Characterization (if applicable)
Width of grass
Width of dense ground cover
Width of wooded vegetation
Total width
Elevation at downslope base of level lip
Elevation at top of bank of the receiving water
Slope (from level lip to to top of bank)
Are any draws present?
Level Spreader Design
Forebay surface area
Feet of level lip needed per cfs
Answer "Y" to one of the following:
Length based on the 1 in/hr storm?
Length based on the 10-yr storm?
Length based on the BMP discharge rate?
Design flow
Is a bypass device provided?
30,600.00 ftz
7,070.00 ftZ
23.10 %
0.41
0.29 cfs
5.00 min
7.22 In/hr
2.08 cfs
N (Y or N)
N (Y or N)
N (Y or N)
Y (Y or N) Please complete filter strip characterization below
N/A
30.00 ft NOTE , Por-;on ok?I w s4r r v o 5,,8e o? e,he 11403
0.00 ft? ka 6? act re- seeded wj4k ?rotss.
30.00 ft
60.00 ft
270.30 fmsl
266.80 fmsl
5.83 % OK
N (Y or N) OK
N/A sq ft OK
39 ft/cfs
Y (Y or N)
N (Y or N)
N (Y or N)
0.29 cfs
Y (Y or N) OK
Form SW401-Level Spreader, Fitter Strip, Restored Riparian Buffer-Rev.5 Parts I. and Il. Design Summary, page 1 of 2
Length of the level lip
Are level spreaders in series?
Bypass Channel Design (if applicable)
Does the bypass discharge through a wetland?
Does the channel enter the stream at an angle?
Dimensions of the channel (see diagram below):
M
B
W
y
Peak velocity in the channel during the 10-yr storm
Channel lining material
•
------------
M
13.00 ft Level spreader length OK
N (Y or N)
N (Y or N)
Y (Y or N)
0.00 ft
6.00 ft
1.00 ft
2.94 fps/1.67 cfs cfs
Class A Riprap

1
M

Form SW401-Level Spreader, Filter Strip, Restored Riparian Buffer-Rev.5 Parts 1. and II. Design Summary, page 2 of 2
Ill. REQUIRED ITEMS CHECKLIST
Please indicate the page or plan sheet numbers where the supporting documentation can be found. An incomplete submittal package will
result in a request for additional information. This will delay final review and approval of the project. Initial in the space provided to
indicate the following design requirements have been met. If the applicant has designated an agent, the agent may initial below. If a
requirement has not been met, attach justification.
Page/ Plan
Initials Sheet No.
VARIES
1. Plans (1" 50' or larger) of the entire site showing:
Design at ultimate build-out,
- Off-site drainage (if applicable),
Delineated drainage basins (include Rational C coefficient per basin),
- Forebay (if applicable),
- High flow bypass system,
Maintenance access,
- Proposed drainage easement and public right of way (ROW), and
- Boundaries of drainage easement.
L?• 1 2. Plan details (1" = 30' or larger) for the level spreader showing:
Forebay (if applicable),
- High flow bypass system,
- One foot topo lines between the level lip and top of stream bank,
- Proposed drainage easement, and
Design at ultimate build-out.
??• ( "
'
3. Section view of the level spreader (1
= 20
or larger) showing:
- Underdrain system (if applicable),
- Level lip,
- Upslope channel, and
- Downslope filter fabric.
4. A date-stamped photograph of the filter strip that clearly shows the type of vegetation that is present.
5. A construction sequence that shows how the level spreader will be protected from sediment until the entire
drainage area is stabilized.
6. The supporting calculations.
1A_ 7. A copy of the signed and notarized operation and maintenance (O&M) agreement.
8. A copy of the deed restrictions (if required).
Form SW401-Level Spreader, Filter Strip, Restored Riparian Buffer-Rev.5 Part III, page 1 of 1
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STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
LEVEL SPREADER, FILTER STRIP AND RESTORED RIPARIAN BUFFER SUPPLEMENT
This form must be completely filled out, printed and submitted.
DO NOT FORGET TO ATTACH THE REQUIRED ITEMS CHECKLIST AND ALL REQUIRED ITEMS (NEXT WORKSHEET)!
I. PROJECT INFORMATION
Project name Avon Forest (Nash County)
Contact name Brad Hart, PE
Phone number 919-469-3340
Date August 7, 2008
Drainage area number Lot 37
II. DESIGN INFORMATION
For Level Spreaders Receiving Flow From a BMP
Type of BMP N/A
Drawdown flow from the BMP cfs
For Level Spreaders Receiving Flow from the Drainage Area
Drainage area 64,800.00 ftZ
Impervious surface area 9,860.00 ftz
Percent impervious 15.22 %
Rational C coefficient 0.36
Peak flow from the 1 in/hr storm 0.54 cfs
Time of concentration 5.00 min
Rainfall intensity, 10-yr storm 7.22 in/hr
Peak flow from the 10-yr storm 3.87 cfs
Where Does the Level Spreader Discharge ?
To a grassed bioretention cell? N (Y or N)
To a mulched bioretention cell? N (Y or N)
To a wetland? N (Y or N)
To a filter strip or riparian buffer? Y (Y or N) Please complete filter step characterization below,
Other (specify) NIA
Filter Strip or Riparian Buffer Characterization (if applicable)
Width of grass 26.00 ft tgOTE: Po,• an W ?'U--r S4rip oo+94e 4 one- NRB
Width of dense ground cover 0.00 >
ft +v b2 irade•.1 4 ire- seeded v, rdk yrasS_
Width of wooded vegetation 30.00 ft
Total width 56.00 ft
Elevation at downslope base of level lip 275.20 fmsl
Elevation at top of bank of the receiving water 272.00 fmsl
Slope (from level lip to to top of bank) 5.71 % OK
Are any draws present? N (Y or N) OK
Level Spreader Design
Forebay surface area NIA sq ft OK
Feet of level lip needed per cfs 41 ft/cfs
Answer "Y" to one of the following:
Length based on the 1 in/hr storm? Y (Y or N)
Length based on the 10-yr storm? N (Y or N)
Length based on the BMP discharge rate? N (Y or N)
Design flow 0.54 cfs
Is a bypass device provided? Y (Y or N) OK
Form SW401-Level Spreader, Fifter Strip, Restored Riparian Buffer-Rev.5 Parts I. and 11. Design Summary, page 1 of 2
Length of the level lip
Are level spreaders in series?
Bypass Channel Design (if applicable)
Does the bypass discharge through a wetland?
Does the channel enter the stream at an angle?
Dimensions of the channel (see diagram below):
M
B
W
y
Peak velocity in the channel during the 10-yr storm
Channel lining material
23.00 It Level spreader length OK
N (Y or N)
N (Y or N)
Y (Y or N)
0.00 ft
6.00 ft
1.00 ft
3.04 fps/ 3.87 cfs cfs
Class B Riprap
• •
------------
M

? t
M
Form SW401-Level Spreader, Fitter Strip, Restored Riparian Buffer-Rev.S Parts 1. and II. Design Summary, page 2 of 2
III. REQUIRED ITEMS CHECKLIST
Please indicate the page or plan sheet numbers where the supporting documentation can be found. An incomplete submittal package will
result in a request for additional information. This will delay final review and approval of the project. Initial in the space provided to
indicate the following design requirements have been met. If the applicant has designated an agent, the agent may initial below. If a
requirement has not been met, attach justification.
Pagel Plan
Initials Sheet No.
VARIrS 1. Plans (1" - 50' or larger) of the entire site showing:
Design at ultimate build-out,
- Off-site drainage (if applicable),
- Delineated drainage basins (include Rational C coefficient per basin),
Forebay (if applicable),
High flow bypass system,
Maintenance access,
Proposed drainage easement and public right of way (ROW), and
Boundaries of drainage easement.
I?• 2. Plan details (1" = 30' or larger) for the level spreader showing:
- Forebay (if applicable),
- High flow bypass system,
- One foot topo lines between the level lip and top of stream bank,
- Proposed drainage easement, and
- Design at ultimate build-out.
I? . 3. Section view of the level spreader (1" = 20' or larger) showing:
- Underdrain system (if applicable),
- Level lip,
- Upslope channel, and
- Downslope filter fabric.
py N/A 4. A date-stamped photograph of the filter strip that clearly shows the type of vegetation that is present.
I?•) 5. A construction sequence that shows how the level spreader will be protected from sediment until the entire

10 drainage area is stabilized.
.1 6. The supporting calculations.
_ 7. A copy of the signed and notarized operation and maintenance (0&M) agreement.
N- 8. A copy of the deed restrictions (if required).
Form SW401-Level Spreader, Filter Strip, Restored Riparian Buffer-Rev.5 Part III, page 1 of 1