HomeMy WebLinkAboutCT 05-10; POINSETTIA PROPERTY; REVISED GEOTECHNICAL EVALIATION OF STORM WATER MANAGEMENT; 2011-01-25Eairth Stra,ta, J/JflIC
Gentechnical, Environmental and Materials Testing Consultants
BETTER PEOPLE • BETTER SERVICE • BETTER RESULTS
January 25, 2011 Project No. 10707-10B
Mr. John Norum, P.E.
K. HOVNANIAN HOMES
1500 South Haven Avenue, Suite 100
Ontario, CA 91761
Subject: Revised Geotechnical Evaluation of Storm Water Management and
Recommendations for Side Yard Drainage for the Proposed 31-Lot Residential
Development, Located on the Southwest Corner of Poinsettia Lane and Pasceo Del
Norte, City of Carlsbad, San Diego County, California
Pursuant to your request, Earth-Strata has reviewed the storm water management plan for the subject
property. The review consisted of evaluating the plans for the single cistern/bio-retention concept
within Lot 6 and Sheets No. 1 through 8, for the "Storm Trap Precast Concrete Modular Storm Water
Management Systems" dated September 29, 2010. The design utilizes the concept that the majority of the
storm water should only be allowed to infiltrate in designated areas.
We recommend that the minimum distance from the proposed house to the flow line of the adjacent _
swale as indicated in the Typical Side Yard w/ Retaining Wall Detail be increased from 3 to 4 feet.
In addition, it is our opinion that the proposed infiltration system in the revised plans noted above should
not be detrimental to the long term stability of the proposed slopes and appurtenant structures. LEA
Additionally, any substantial alterations to the plans to include infiltration throughout the site is not
recommended. As noted within the referenced geotechnical reports, we are concerned from a
geotechnical point of view if storm water is not controlled and allowed to infiltrate throughout the site.
After the site is rough graded geological contacts will exist between the native earth materials and the
various artificial fill materials. If water is encouraged to infiltrate at numerous locations throughout the
site, the groundwater could be considerably detrimental to the long term stability of the slopes and
appurtenant structures.
We hope that this further clarifies the need for controlling and limiting areas where infiltration is
permitted.
F 1P
EARTH - STRATA, INC. 26047 JEFFERSON AVENUE, SUITE C, MURRIETA, CA 92562• OFFICE (951)461-4028 • FAX (951)461-4058 • WWW.EARTH-STRATA.COM
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S I
The opportunity to be of service is appreciated. Should you have any questions or require further
clarification, please notify our office at your earliest convenience.
Respectfully submitted,
]EART]H[STRATA, ][NC.
Chad E. Welke, PG, CEG, PE
Principal Geologist/Engineer
ESSIo\
St en M. Poole, PE, GE
Principal Engineer
CW/SMP/am
Attachment: APPENDIX A - References (Rear of Text)
Distribution: (2) Addressee
(3) Mr. Craig Kahlen - Rick Engineering
APPENDIX A
I
REFERENCES
APPENDIX A
References
Earth-Strata, Inc., 2010, Interpretive Report for Infiltration System, Proposed 29-Lot Residential
Development, Located on the Southwest Corner of Poinsettia Lane and Lowder Lane City of
Carlsbad, San Diego County, California, dated May 6.
2010a, Preliminary Geotechnical Interpretive Report, Proposed 29-Lot Residential Development,
Located on the Southwest Corner of Poinsettia Lane and Lowder Lane City of Carlsbad, San
Diego County, California, dated May 11.
2010b, Geotechnical Review of Draft Retaining Wall Alternative Analysis Report, Proposed 29-Lot
Residential Development, Located on the Southwest Corner of Poinsettia Lane and Lowder
Lane City of Carlsbad, San Diego County, California, dated May 25.
_______• 2010, Preliminary Turf Block Recommendation Letter, Proposed Residential Development,
Located on the Southwest Corner of Poinsettia Lane and Lowder Lane, City of Carlsbad, San
Diego County, California, dated September 14.
_______• 2010, Geotechnical Review of Foundation Plans for the Proposed 25-Lot Residential Development,
Located on the Southwest Corner of Poinsettia Lane and Pasceo Del Norte, City of Carlsbad,
San Diego County, California, dated October 20.
________• 2010, Supplemental Geotechnical Retaining Wall Design Recommendations, Proposed Poinsettia
Residential Development, Located on the Southwest Corner of Poinsettia Lane and Lowder
Lane City of Carlsbad, San Diego County, California, dated October 20.
_______• 2010, Update Geotechnical Retaining Wall Design Recommendations, Proposed La Marea
Residential Development, Located on the Southwest Corner of Poinsettia Lane and Lowder
Lane City of Carlsbad, San Diego County, California, dated November 11.
_______• 2010, Geotechnical Evaluation of Storm Water Managementfor the Proposed 25-Lot Residential
Development, Located on the Southwest Corner of Poinsettia Lane and Pasceo Del Norte, City
of Carlsbad, San Diego County, California, dated November 11.