20150023 Ver 1_Buffer Variance Request_20141229

GENESIS
NORTH CAROLINA
I
TO: Tom Anderson
City of,lacksonvidle
FROM: Kevin Krick, P.E,, LEED AP Y,
Genesis North Carolina, LLP
RE: Jacksonville Marketplace — Parcels A, B, C, and D
Request for Stream Buffer Variance
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,ION I
We have determined that the unnamed tributary north of the Jacksonville Marketplace property is classified as
an "intermittent stream". It is our understanding from Ordinance 62009-0t7
) —An Ordinance to Enact Pliase lJ
Stormwater Standards for tho gf V ol` /ac %svnvllle and an accompanying memo dated February 29, 2012, that
"all built-upon area" shall be at a minimum of 50 feet landward of all perennial and intermittent surface waters.
We are requesting a variance of this requirement as described below.
Parcel A
The North Carolina Division of Water Quality defines "built-upon area" as a measure of the impervious cover
for a site. It further defines an impervious surface as any material that prevents infiltration of water into the soil.
We have designed the proposed infrastructure, using pervious concrete, in a manner that keeps all built-upon
area landward of the 50 feet buffer, with the exception of approximately 260 square feet, which encroaches
approximately 10 feet into the buffer. In other areas on Parcel A, we have extended the stream buffer up to a
maximum of 60 feet.
Parcel B
We have designed the proposed infrastructure to avoid a majority of the stream buffer, with the exception of
approximately 16 square feet, which encroaches approximately 2 feet into the buffer. This design includes the
use of pervious concrete for future parking spaces. This encroachment is the result of the following:
The proposed access road was designed to connect to two (2) fixed ends: 1) the cross-driveway at
Marine Chevrolet and 2) Gateway Drive North. The connection at Gateway Drive North was placed as
far north of Western Boulevard as possible to meet the minimum requirements of the North Carolina
Department of Transportation (NCDOT) and was also placed adjacent to an existing bulkhead that was
installed and permitted previously, by others. The internal portion of the access road was designed as
far back in the parcels as possible to allow for adequate internal driveway circulation and parking to
meet the City of Jacksonville zoning requirements. Because of this, it is not possible to move the
access road any closer to the front of the site and away from the stream buffer,
In other areas an Parcel B, we have extended the stream buffer up to a maximum of 100 feet.

GENESUS
NORTH CAROLINA
11=1
On Parcel C and D, we are proposing a stream buffer of 15 foot, up to the point where the buffer joins the
existing and permitted bulkhead. The design includes the use of pervious concrete for the parking spaces.
Because of this design, an effective buffer of approximately 30 feet will be maintained throughout Parcel C and
most of Parcel D. The encroachment is the result of the proposed access road location as described
previously, In addition, because of the relatively small size of Parcel C, the access road must be located as
proposed to accommodate the minimum number of parking spaces required by zoning ordinance.
Other Information
In an effort to preserve water quality in the stream buffer, we have removed the stormwater detention ponds
and replaced them with underground stormwator detention beneath the parking lots, This will reduce the
amount of land disturbance in the stream buffers, which will reduce the potential for sediment migration into
the streams. This will also result in the preservation of a greater area of existing vegetation than previously
allowed and proposed.