HomeMy WebLinkAboutCT 12-07; VALLEY 17; ANDRE LECOMPTE BASIN CONSTRUCTION CHANGE FOR LOT 13 OF MAP 15996; 2017-10-16October 16, 2017
City of Carlsbad
Land Development Engineering
1635 Faraday Ave
Carlsbad, CA 92008
ATTN: Tecla Levy
BENLUND
ENGINEERING
IJC FWIEIM
OCT 232017
LAND DEVELOPMENT
ENGINEERING
RE: Andre Lecompte Basin Construction Change for Lot 13 of Map15996, APN: 156-212-45
"Valley 17" SDP 12-07, CT 12-07, GP 480-4A
The owner of the property in question is proposing to build a retaining wall in lieu of an existing 2:1
slope used for a water quality and detention basin. Grading Plan 480-4A shows the basin grading as
close as 4' from the residence. The proposed retaining wall will effectively move the basin extents away
from the home.
Basin Area
Although the basin geometry will change slightly the proposed area of the basin bottom (required for
water quality) will be greater than existing. The required basin area per the approved "Stormwater
Management Plan" (SWMP 13-21) by Huitt-Zollars dated 8/14/14 is 792 ft2 with 850 ft2 being built by
the existing Grading Plans. This proposed project will increase the basin area to over 1,000 ft2.
Basin Volume
Although the basin geometry will change slightly the basin volume (required for water quality and 100-
year detention) will be greater than required. The required basin volume per the approved "Final
Hydrologic & Hydraulic Report" by Huitt-Zollars dated 8/14/14 is 0.048 ac-ft or 2,091 ft3. This volume
corresponds to a maximum ponding depth of 1.85' which matches the "6" MAX (WATER QUALITY
STORAGE)" and "1.35' (100-YR DETENTION STORAGE)" depths shown on the "Water Quality Basin Lot 13
Detail Profile View" detail on sheet 2 of Grading Plan 480-4A. This proposed project will create a basin
holding 2,300 ft3.
Respectfully, CIv7 &
°•
cc
No C68849
Benjamin R. Lund, PE, PLS
Principal
Ben Lund Engineering
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