HomeMy WebLinkAboutCT 98-14; Thompson/Tabata; Tentative Map (CT) (136)c
C 0 N S U LTI N G
August 15, 2002
Clyde Wickham
City of Carlsbad, Engineering Department
1635 Faraday Avenue
Carlsbad, CA 92008
Subject: CT 98-14 (Thompson/Tabata): Substantial Conformance Exhibit Justifications
Dear Mr. Wickham:
Submitted for your review is the substantial conformance exhibit for CT 98-14, the
Thompson/Tabata residential development. As we discussed in our meeting on August 9, 2002,
the majority of the revisions to the Thompson/Tabata conforming tentative map are required to
balance the grading of the site following the implementation of the applicable City-imposed
conditions of approval and datum correction. The grading modifications compensate for the
additional fill needed for the required redesign of "C" Street, access issues for the Tabata parcel
on the north side of Poinsettia Lane, and the redesign of "F" Street. The remainder of the
revisions have been incorporated to improve the overall site design, improve the construction
phasing schedule, and incorporate the conditions imposed by the California Coastal
Commission's approval of the Local Coastal Program Amendment 98-04.
The following list itemizes, by sheet number, the revisions to the conforming tentative map and
provides a justification for each modification:
Sheet 1
1. Revised phasing and lot numbering.
Construction logistics required that the phasing be revised to address the various
construction and improvement issues in a more time- and resource-efficient
manner.
Lots must be numbered in sequential order of tract recording. When the phasing
changed, the lot numbering changed in order to maintain sequential numbering.
Sheet 2
1. Revised lot sizes on conforming tentative map lot numbers 32-34, 62, 63, 205-210 &
220-223.
Lot lines were adjusted as a result of changes due to existing field conditions.
Sheet 3
1. Revised pad elevations on lot numbers 225-228, 237 & 243.
Pad adjustments were required to balance site and help eliminate the need for
offsite improvements.
PLANNING B DESIGN • CONSTRUCTION
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2. Added off-site grading east of lots 227-230.
Geotechnical investigations conducted in the course of construction planning
revealed a significant quantity of buried trash and unstable soils in this area. The
off-site grading is necessary to stabilize the slope.
Sheet 4
1. Revised lot line on lots 32 & 33 and eliminated retaining wall on lot 32.
These are minor design changes for the model complex. The retaining wall
proved to be unnecessary.
2. Added storm drain on "A" Street.
The addition of the storm drain eliminates street cross-gutters.
3. Revised pad elevations for lots 1-20, 30-47, 49-59
These pads were lowered 3' to provide needed fill as a result of the required
design changes and datum change. The change in grade is relative throughout
the Phase 1 area of the site. All buildings and infrastructure were lowered
together 3 feet.
4. Revised storm drain between lots 7 & 8 on off-site segment
The original design would have resulted in grading and improvements within the
area now designated as a conservation easement as a result of the Coastal
Commission's approval ofLCPA 98-04. The revised design eliminates the need
for grading and improvement in the deed restricted area.
Sheet 5
1. Replaced retaining walls on lot 166 with loffel wall.
UBC requires a larger house set back than shown on the conforming tentative
map. The loffel wall is a plantable wall which will minimize the visual impact of
the retaining structure.
2. Revised pad elevations for lot numbers 21-29, 48, 108-109, 119-134, 160-164, 142-
143.
These pads were lowered up to 3' to provide more fill soil needed as a result of
the required design changes and datum change discussed above.
3. Added retaining wall to lot 152.
Wall is necessary to provide UBC required setbacks, stabilize the slope and
provide more useable yard space.
Sheet 6
1. Revised grading and pad elevations on lots 205-213 & 218-224.
These modifications were a result of minor changes to the design of the street
which improves the relationship between the subject development and the
Tabata "Not a Part" parcel.
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2. Revised storm drain alignment behind lot 212, revised sewer alignment on lot 213,
and added retaining walls on lots 212 & 213.
These revisions were required to reduce the amount of off-site disturbance to the
adjacent development. The retaining wall is required to provide an easement for
the revised sewer alignment.
Sheet 7
1. Revised grading and pad elevations on lots 60-71, 77-81, 84-87, 198-202.
Pad adjustments were required to balance site.
2. Revised storm drain, sewer, water, and street alignment on "E" Street to avoid
habitat within lots 189-192.
These changes are conditions of approval forLCPA 98-04, imposed by the
Coastal Commission.
3. Revised tract boundary between lots 198-201 & 204.
This modification eliminates cross lot drainage
4. Realigned storm drain main from Alyssum to "E" Street.
This modification eliminates the need for off site construction.
5. Added sewer main along affordable housing entrance road.
This revision is necessary to allow for Phase 1 operation prior to Phase 3
grading, and relates to the changes made on Sheet 1.
Sheet 7A
1. Revised tract boundary between lots 199-204.
This modification eliminates cross lot drainage
Sheet 8
1. Revised grading and pad elevations on lots 71-77, 87-118, 168-198.
Pad adjustments were required to balance site.
2. Revised storm drain, sewer, water, and street alignment on "E" Street to avoid
habitat within lots 189-192.
These changes are conditions of approval for LCPA 98-04, imposed by the
Coastal Commission.
If you should have any questions regarding these changes, please contact me at (949) 855-
5719.
Sincere!
Mark S. Anderson, P.E.
Senior Vice President
Land Development
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