HomeMy WebLinkAboutAMEND 2021-0004; DISTRIBUTE LOTS 13-15 SHELL BUILDING; LETTER AMENDMENT - STORM WATER QUALITY MANAGEMENT PLAN (SWQMP); 2021-03-24A:COM
March 24, 2021
City of Carlsbad
Land Development Engineering
1635 Faraday Avenue
Carlsbad, CA 92008
AECOM
300 Lakeside Dr., Ste. 400
Oakland, CA 94612
www.aecom.com
510 893 3600 tel
510 874 3268 fax
Subject: Letter Amendment-Stonn Water Quality Management Plan (SWQMP),
Permit No. GR2017-0004, Site Address 3266 Uonshead Avenue, Carlsbad, CA
Attn: Land Development Engineering Department
AECOM is pleased to provide the City of Carlsbad with this written correspondence regarding our
review of the proposed improvements relative to the existing SWQMP for Permit No. GR2017-0004.
Please note, given the insignificant nature of this change, this update or amendment is being
provided mainly for purposes of record keeping so as to document that a very minor change was
made to the parking lot but given the small relative decrease, no change to the amount of runoff for
this area was recognized. The information below summarizes the background and conclusion
associated with this change.
Per the attached Figure 1, AECOM is to remove 27,692 s.f. of existing asphaltic pavement and
replace it with a slightly lesser amount of 27,539 s.f. of proposed asphaltic pavement, resulting in a
small net decrease to the impervious area of 153 s.f. for this localized area of the site. The location of
the new asphalt is in the exact same location (see Figure 1) as it was previously defined in SWQMP
Permit No. GR2017-0004. As a result of this very small relative change {Existing Area minus
Proposed Area) of{-) 153 s.f. which equates to(-) 0.0035 acres reduction in area, it would potentially
decrease the proposed amount of runoff for this area. However, given the small magnitude of this
reduction in area, the associated runoff that would result is insignificant. With this in mind there is no
change to the runoff amount that gets directed toward the bioretention facility located on the
northwest side of the parking lot and therefore no change to the SWQMP will be required for Permit
No. GR2017-0004.
Sincerely,
William Beaman
Principal Civil Engineer
"EXISTING 27,692 SF IMPERVlOUS
SURFACE RUNOFF FLOWS TO THE
EXISTING BtORETEl'ITION 8M.P SHOWN
BELOW
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I IMPERVIOUS AREA TO 8E REMOVED • 27,692 SQ.FT -1 0l"'°'-ITI0'11 l.lOENC>
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PRE-DEVELOPMENT CONDITIONS -PARKING LOT
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*PROPOSED PARKING REDUCES IMPERVIOUS AREA BY 153 SQ.FT. -/-"
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POST-DEVELOPMENT CONDITIONS -PARKING LOT
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A:COM
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