20011549 Ver 1_Stormwater Info_20030117

WITHERS &- RAVE N E L LETTER O TRANSWTTAL
ENGINEERS I PLANNERS I SURVEYORS
111 MacKenan Drive
CARY, NORTH CAROLINA, 27511
[phone]
FAX [phone]oo8
To: NCDENR
Division of Water Quality
2321 Crabtree Blvd
Raleigh, North Carolina 276o4
DATE 01/17/03 JOB NO. 201113.1
ATTENTION Todd St. John
PHONE # [phone]
RE: Lon Lake Subdivision
Lot 2, Phase
Phase - Stormwater Management Plan

WE ARE SENDING YOU ® Attached ? Under separate cover via
Shop Drawings ? Prints ® Plans ? Samples
? Copy of Letter ? Change order ? Diskette ?
COPIES DATE NO. DESCRIPTION
2 Phase Construction Plans
1 Supporting Calculations
1 O&M Agreement

THESE ARE TRANSMITTED as checked below:
® For approval ? Approved as submitted ? Resubmit copies for approval
? For your use ? Approved as noted ? Submit copies for distribution
? As requested ? Returned for corrections ? Return corrected prints
? For review and comment ?
? FOR BIDS DUE
REMARKS: 20 ? PRINTS RETURNED AFTER LOAN TO US
CC Zee j?v IveR C/1 G

COPY TO: File
SIGNED: Ken Jesneck, PE
/f enclosures are not as noted, kindly notify us at once.
the following items:
? Specifications
WITHERS,-'N'
, RAVEN EL
ENGINEERS I PLANNERS I SURVEYORS
January 17, 2003
Mr. Todd St. John
North Carolina Department of Environment and Natural Resources
Division of Water Quality
2321 Crabtree Boulevard
Raleigh, North Carolina 27604-226o
Re: Storm Water Management Plan
Long Lake Subdivision
DWQ Project Number 01-1549
W&R Project 201113.0
Mr. St. John
Please find the attached Storm Water Management Plan, Phase 4, for the Long Lake
Subdivision. This submittal is in response to the conditions of the April 18, 2002s401 Water
Quality Certification, Additional Conditions. The plans, Operation and Maintenance
Agreement, and supporting calculations are included with this submittal for this structural
management practices. The structural management practice proposed for Tract 4 is being
postponed until Phase 5.
Please advise should you have any questions or comments.
Sincerely,
WITH RS &-RAVENEL, INC.
Ken jesneck, P
Attachments
iii MacKenan Drive i Cary, North Carolina 27511 1 tel: [phone] fax: [phone]oo8 i www.withersravenet.com
LONG LAKE SUBDIVISION
TRACT 2 POND F (FES #50) EXTENDED DRY DETENTION BASIN
OPERATION AND MAINTENANCE AGREEMENT
The dry detention basin system is defined as the dry detention basin, pre-treatment including forebays and the
vegetated filter if one is provided.
Maintenance activities shall be performed as follows:
After every significant runoff producing rainfall event and at least monthly:
a. Inspect the dry detention basin system for sediment accumulation, erosion, trash accumulation,
vegetated cover, and general condition.
b. Check and clear the orifice on the skimmer of any obstructions such that drawdown of the temporary
pool occurs within 2 to 5 days as designed.
2. Repair eroded areas immediately, re-seed as necessary to maintain good vegetative cover, mow
vegetative cover to maintain a maximum height of six inches, and remove trash as needed.
3. Inspect and repair the collection system (i.e. catch basins, piping, swales, riprap, etc.) quarterly to
maintain proper functioning.
4. Remove accumulated sediment from the dry detention basin system semi-annually or when depth is
reduced to 75% of the original design depth (see diagram below). Removed sediment shall be disposed
of in an appropriate manner and shall be handled in a manner that will not adversely impact water quality
(i.e. stockpiling near a detention basin or stream, etc.).
The measuring device used to determine the sediment elevation shall be such that it will give an accurate
depth reading.
When the sediment depth reads 1.6 feet in the main pond, the sediment shall be removed.
When the sediment depth reads 1.6 feet in the forebay, the sediment shall be removed.
BASIN DIAGRAM
0
Sediment emoval El.
Top of Dam Elevation 365.0 ft
7
_ Sediment Removal Elevation 360.6 ft 75%
------ ------- -
Bottom evation 359.0 5% ---------------------------------------------= ------
FOREBAY
Bottom Elevation 359.0 ft 25%
MAIN POND
Page 1 of 2
LONG LAKE SUBDIVISION
TRACT 2 POND F (FES #50) EXTENDED DRY DETENTION BASIN
OPERATION AND MAINTENANCE AGREEMENT
5. Remove cattails and other indigenous wetland plants when they cover 50% of the basin surface
6. All components of the dry detention basin system shall be maintained in good working order.
7. Level spreaders or other structures that provide diffuse flow shall be maintained every six months. All
accumulated sediment and debris shall be removed from the structure, and a level elevation shall be
maintained across the entire flow spreading structure. Any down gradient erosion must be repaired and/or
replanted as necessary.
I acknowledge and agree by my signature below that I am responsible for the performance of the seven
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.
Print name: Alan C. Hill
Title Director of Land
Address: Pulte Home Corporation, 401 Harrison Oaks Blvd., Suite 250, Cary, NC 27513
Phone:
Signatu
Date:
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
personally appeared before me this day of , and acknowledge the due
execution of the forgoing wet [wetland] detention basin maintenance requirements. Witness my hand and
official seal,
SEAL
My commission expires
Page 2 of 2
WITHERS ?\-
?7 RAVENEL
ENGINEERS I PLANNERS I SURVEYORS
February 4, 2003
Mr. Todd St. John
North Carolina Department of Environment and Natural Resources
Division of Water Quality
2321 Crabtree Boulevard
Raleigh, North Carolina 27604-226o
Re: Storm Water Management Plan
Long Lake Subdivision
DWQ Project Number 01-1549
W&R Project 201113.0
Dear Mr. St. John:
Enclosed you will find the revised Phase 4, Storm Water Management Plan. The revision is
the relocation of the skimmer discharge to another location with its own rip-rap dissipater
pad. Please note that the maximum flow rate for the skimmer is 0.055 cubic feet per second.
If you have any questions, please contact me at [phone]•
Sincerely,
W117HER!q (?r-RAVEt4EL, INC.
Jesnec
in MacKenan Drive i Cary, North Carolina 27511 1 tel: [phone] fax: [phone]oo8 i www.withersravenel.com