HomeMy WebLinkAbout20140822 Ver 1_More Info Received_20140416Burdette, Jennifer a
From: Neal Tucker <NTucker @stimmelpa.com>
Sent: Wednesday, April 16, 2014 4:24 PM
To: Burdette, Jennifer a
Cc: Ana Jaramillo (AJaramillo @toknc.com); Jeff Hunter Qhunter @popecompanies.com);
'Hank Perkins' (hank @eastcoastcapital.net); Homewood, Sue; Tom Davis
(tdavis @leainc.com)
Subject: 13 -114 Variance Request - Additonal Information - Blue Diamond Investment
Company
Attachments: Blue Diamond Variance - WQC Questions- Answers 4- 16- 14.pdf; Blue Diamond
Variance Request - Appended - WQC -EMC 4- 16- 14.pdf
Jennifer,
Attached you will find a letter addressing the questions in your e -mail to Ana Jaramillo dated April 7, 2014 with backup
information, and the final version of the appended letter requesting approval of the variance from the Town of
Kernersville.
Please contact me if you need additional information.
Thanks
C wMilikkk
stimmel
LANDSCAPE ARCHITECTURE I CIVIL ENGINEERING I LAND PLANNING
J. Neal Tucker, P.E. Partner/ Director oil' Civil Engineering
336.723.1067 x104 I cell: 336.817.2524
601 N. Trade St. Suite 200 1 Winston - Salem, NC 27101
www.stimmelpa.com
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April 16.2014
Ms. Jennifer Burd*tbe
4O1 /Buffer Coordinator
401 & Buffer Permitting Unit
Wetlands Branch
NCDENR — OVVR
1650 Mail Service Center
Ra|eigh.NC 27698'1650
Subject: Answers ho Questions from the Water Resources Committee Regarding the
Blue Diamond, LLC Variance Request
Dear Ms. Burdette,
Stimmel Associates, P.A. is working as an engineering consultant to Blue Diamond Investment Company, LLC for their
property east of the Veterans Administration Hospital inKememviUe. The purpose of this letter iohz address questions
from the Water Quality Committee outlined in your e-mail to Ana Jaramillo with the Town of Kernersville dated April 7,
2014. The questions / additional information requested and answers are as follows:
1. Conceptual plan of BMP on the VA site to handle all stormwater from upslope.
A: | have consulted with the VA's Civil Engineering consultant regarding this, During the design phase of the VA
project, they looked sd designing the pond to handle all runoff from upa|ope. however there was insufficient space
to fit the pond nn the site. A plan was not prepared representing this condition.
`
2. Cost difference between the VA treating only their stormwater vs. treating all stormwater from upslope.
A: The cost difference was not determined since a pond to handle all upslope runoff would not fit on the VA site.
%. Conceptual plan and design of BMP for Blue Diamond site including calculations used to size the BMP.
A: See the attached Drainage Area Map by Stimmel Associates with backup calculations. This drawing
represents a single pond to handle runoff in the developed condition. |i does not represent the two separate
B[NP'e that would be required for the pre-developed condition.
4. A complete site plan for the B01Pon the VAsite.
A: See the attached Overall Storm Drainage Plan by Littlejohn Engineering, and annotated by Stimmel
Associates.
5. Ownership history.
A: See letter from Jeff Hunter with Pope Companies, partner in Blue Diamond Investment Company, LLC,
addressing ownership history. -
G. Determination if EQ13514 applies to the VAHospital. If yes, then what provisions will be taken tocomply
with the Executive Order.
A: It in my understanding that this question has been addressed by Sue Homewood with NCOENR-DVVR. and that
E013514 does not apply.
W1 Trade Street Suite 2,00
Winston mmiem.wc 27101-2916
P, 336 723 1067 F, 3a6,723,1069
Blue Diamond Property
Shznnwaber Management Variance Request
September 27.2O13
Page `
Please contact meif you require additional information.
Sincerely,
J, Neal Tucker, PE
Stimmel Associates, PA
Attachments
Co: Jeff Hunter, Pope Companies
Ana Jaramillo, Town of Kernersville
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September 27, 2013
April 10, 2014 (Appended)
Town of Kernersville
P.O. Drawer 728
Kernersville, NC 27285
Attn: Russell Radford, PE, Town Engineer
Subject: Request for Variance for
Stormwater Management Requirement in the Pre - Developed Condition
Blue Diamond Property adjacent to the Proposed Veterans Administration Hospital
Dear Russell,
I am writing this letter on behalf of Blue Diamond Investments to request a variance in the timing of installation of
stormwater management BMP's for the subject property. The Veterans Administration (VA) Hospital site lies downslope of
the Blue Diamond Investments property. The VA site will have its own stormwater management system, sized to treat
runoff from its site only, therfore a stormwater bypass system must be constructed to convey stormwater runoff from the
Blue Diamond property around or through the VA site to keep runoff from Blue Diamond property separate from that of the
VA site. The bypass system discharge point falls within the West Fork Deep River buffer which is a tributary within the
Randleman Lake Water Supply Watershed. A rip rap lined channel will be provided through the buffer from the discharge
point to the river. The Randleman Rules require that concentrated runoff from manmade conveyances be converted to
diffuse flow before the runoff enters Zone 2 of the buffer, unless stormwater management is provided for the runoff. The
State's Stormwater BMP Manual requires 50 linear feet of level spreader per cfs of flow to provide diffuse flow from a
concentrated discharge point. For the 1.0 in. /hr. rainfall, 1,778 linear feet of level spreader is required for the flow from the
bypass line. A second requirement for level spreaders per the State Manual is that the maximum flow that can be directed
to a single level spreader is 2 cfs. With this limitation, the flow from the bypass line would have to be split into 18 discrete
level spreaders. Additionally, flows that exceed the 2 cfs capacity of the level spreaders are required to be diverted away
from the level spreaders. These higher rate flows would have to be channelized through the buffer to the stream as
currently planned, which is what the developer is requesting approval of. Given these constraints, it is impractical to
convert concentrated flow from the bypass line to diffuse flow. Since sufficient space to convert discharge from the bypass
system to diffuse flow is not available outside the buffer, a stormwater BMP is required by the Rules. Given the
topographic characteristics of the Blue Diamond property and other upslope properties, Blue Diamond Investments is
requesting a variance to delay installation of the BMP until such time as development of the Blue Diamond property
begins.
A development plan has not been prepared for the Blue Diamond property. Designing and building a stormwater BMP
without a development plan in place causes the development to be designed around the BMP, which may not yield the
best and highest use of the property. The topography of the Blue Diamond property upslope of the VA site forms two
drainage basins. Providing stormwater management for the property prior to development would require two BMP's to be
constructed, or the majority of the property to be graded to drain to a central location. If BMP's are constructed at the
current drainage collection points prior to development, these locations may not work with the final development plan and
would have to be moved. This would certainly be the case for the drainage feature adjacent to Kernersville Medical
Parkway, as the road frontage will be the most valuable property from a development perspective. Either of these
scenarios, mass grading or building BMP's represents a significant financial burden to the developer prior to development
activity commencing.
60,11 fit, Trade Streal Suite, 2114
ffim t n Sotern„ NC 271101.2916
R 336723,1067 F: 336323 1069
Blue Diamond Property
Stormwater Management Variance Request
September 27, 2013
Page 2
What are the impacts to the VA site if their BMP is upsized to treat post - developed runoff from the Blue Diamond
property ?:
As the attached VA storm drainage plan reflects, there is little to no room to expand the stormwater pond. We have
consulted with the VA's Civil Engineering consultant regarding upsizing their pond to accommodate runoff from the Blue
Diamond and upslope residential properties in a developed condition. The VA's consultant looked at this during the design
phase of the project and a pond of that size would not fit within the available space on the property.
What are the impacts to the VA site if their BMP is upsized to treat pre - developed runoff from the Blue Diamond
property, then bypass Blue Diamond runoff in the post - developed condition ?:
Although not specifically studied, it is possible that the VA pond as designed could accommodate the area draining to the
bypass system in the pre - developed condition, however when the Blue Diamond property develops, the bypass system
would have to be disconnected from the VA pond and extended to the Deep River, causing significant disruption and
damage to the VA site. Given this, it is unlikely that the VA and the site developer would agree to this arrangement.
What are the impacts to water quality in the Deep River if pre - developed runoff from the Blue Diamond property is
not treated ?:
The total basin area draining to the bypass system is approximately 48 acres. The Blue Diamond property (28.8 acres) is
undeveloped, with 0% built upon area (BUA). The remaining drainage area (19.2 acres) upslope of the Blue Diamond
property is very sparsely developed as large lot residential. The upslope area currently has approximately 7% BUA. The
aggregate BUA of all properties upslope of the VA site is 2.79 %. Runoff from this area flows overland through wooded
areas and vegetated conveyances to the point where the bypass system through the VA site would intercept this water.
The shortest flow path from the nearest rooftop is at least 700 feet from the bypass system inlet point.
Given the extremely low BUA of the upslope properties and the length of the vegetated conveyances, we believe that
adequate treatment is already being provided within the natural system without having to build an engineered BMP prior to
development of the property. Untreated stormwater runoff from the Blue Diamond property discharged into the buffer from
the bypass system will have the same characteristics in terms of quality as untreated runoff from the same area discharged
into the buffer through the natural system that existed prior to development of the VA site. We believe that water quality
will not be compromised by deferring installation of the Blue Diamond stormwater management BMP until development of
that property occurs, and that the intent of the Randleman Rules will be satisfied.
Blue Diamond Investments understands that stormwater management will be required for their development. They are
simply requesting that final design and construction of the stormwater BMP be deferred until development of their property
begins. The specific time frame anticipated for development of the property to begin moving forward is unknown, however
we believe that completion of the Kernersville Medical Parkway in the fourth quarter of 2013 will be a primary catalyst for
development in this area.
We believe that granting this variance request is justifiable for the following reasons:
• It is a minor deviation from the requirements of the Randleman Rules, since it only requests that implementation of
the stormwater management plan be deferred until development of the Blue Diamond property.
• Deferring implementation of the stormwater management plan will not negatively impact surface waters.
• The requirement for implementation of the stormwater management plan prior to development of Blue Diamond
property is not due to actions of Blue Diamond Investments, but rather due to development of the adjacent VA
property.
• The requirement for implementation of stormwater management prior to development of property is rare, and in
this case only applies to Blue Diamond Investments and not to the upslope residential property owners, which are
Blue Diamond Property
Stormwater Management Variance Request
September 27, 2013
Page 3
also contributors of runoff to the bypass system.
It is in harmony with the general purpose and intent of the State's riparian buffer protection requirements and the
Town's Ordinance and preserves its spirit.
The public safety and welfare have been assured, water quality has been protected and substantial justice has
been done.
Thank you for your consideration of this variance request. Please contact me if you require additional information.
Sincerely,
J. Neal Tucker, PE
Stimmel Associates, PA
Cc: Jeff Hunter, Pope Companies
Ana Jaramillo, Town of Kernersville
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