HomeMy WebLinkAboutPD 2021-0040; 786 PALM AVENUE; GEOTECHNICAL DRAINAGE REVIEW PROPOSED RESIDENCE WITH ADU; 2022-08-23GeoTek, Inc.
1384 Poinsettia Avenue, Suite A Vista, CA 92081 -8505
(760) 599-0509 (760) 599-0593 f www.geotekusa.com
AB 3
C/O P&E Coast Construction
2834 La Mirada Drive, Suite E
Vista, California 9208 I
Subject:
August 23, 2022
Project No. 3653-SD
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Geotechni cal Drainage Review
Proposed Res id ence with ADU
786 Palm Avenue APN 2 14-39-0 IO & 11
Carlsbad, California 92008
SEP 14 2n27
LANO DCVi:LO~MENT
ENGINEERING
GeoTek, Inc has reviewed the subject project "Grading Plans" by bHA, Inc. It was o ur
prior understanding based on plans avail able t hat the areas on the lots that do not meet
typical site offsets for draining were intended as non-permeable surfaces. We now
understand these are to be vegetated swales. The areas that do not meet the generally
required setbacks from the foundations on the two lots are limited and are as follows:
I) The area on Lot IO is along the north side of the house for a distance of
approximately 29 feet. Based on the "Roof Plan" indicated as Delta I dated
December 22, 2021 provided to Geo Tel< by Joe Barbano Architect no roof
drainage is directed to this area. The Grading Plan indicates that with the
exception of approximately 3.5 feet to the east that drains through the area
rainfall would be limited to incident precipitation. The flow line is approximately 3
feet from the foundation .
2) The area on Lot I I is along the east side of the house for a distance of
approximately 20 feet. Based on the "Roof Plan" indicated as Delta I dated
December 22, 2021 provided to Geo Tek by Joe Barbano Architect a small section
of "lower roof" drains to this area. The Grading Plan indicates t hat rainfall would
be limited to incident precipitation as there is a high point at the northern corner
of the house. The flow line is approximately 1.5 feet from the house foundation .
Structural Plans prepared by Nader's Design Consulting, Inc. as indicated on the enclosed
reference list, indicate that minimum exterior footing depth will be 18 inches on both lots. Our
prior site reports indicated the soils and non-active/low expansive.
GEOTECHNICAL I ENVIRONMENTAL I MATERIALS
AB 3
Geotechnical Drainage Review
786 Palm Avenue
August 23, 2022
Project No. 3653-SD
Page 2
We were provided with a "Drainage Report" by bHA which concluded that "Side yard
vegetated swales adjacent to each building will drain not less than 2% away from the building
and not less than I% longitudinal slope. See vegetated swale calculations in Chapter 3 (of that
report) showing that the vegetated swales can adequately convey the calculated runoff for each
lot at longitudinal slopes between I% to 2% and sides slopes between 2% and 5%."
Based on the non-active/low expansive soils conditions identified on site, the minimum 18 inch
footing depth and the bHA "Drainage Report" conclusions, the proposed site drainage is
considered acceptable from a geotechnical standard.
The opportunity to be of service is sincerely appreciated. If you should have any questions,
please do not hesitate to call our office.
Respectfully Sub ·
GeoTek, Inc.
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Principal Geologist
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Edwin R. Cunningham, Rci81867
Project Engineer
GEOTEK
AB 3
Geotechnical Drainage Review
786 Palm Avenue
References:
August 23, 2022
Project No. 3653-SD
Page 3
I. "Limited Geotechnical Evaluation, Proposed Residence with ADU, 786 Palm Avenue
APN 214-39-011, Carlsbad, California 92008" by GeoTek, Inc. dated August 14, 2020
(PN 3653-SD)
2. "Grading Plans for: 786 Palm Avenue, Carlsbad, California" by bHA Inc. print date
September 13, 2021
3. Structural Plans: Single Family Home, ADU, Casita & Garage 786 Palm Avenue,
Carlsbad, CA specifically Foundation Plan Unit IO Sheet SI, Foundation Plan Unit I I
also Sheet SI Structural Details Sheet SD I, by Nader's Design Consulting, Inc dated
November 23, 2021
4. "Drainage Report 786 Palm Avenue, Carlsbad, California" by bHA Inc. dated August I 0,
2022
GEOTEK