HomeMy WebLinkAboutAV 91-12; Hill Residence; Administrative Variance (AV) (8)August 19, 1993
Mr. Steve Hill
3317 Cadencia Street
Carlsbad, CA 92009
PROPERTY DEVELOPMENT ENGINEERS, INC.
1859 S. ESCONDIDO BLVD., ESCONDIDO, CA 92025
JOHN E. VERNON, PRESIDENT, RCE 21121, GE 858
CHARLES W. DAVIS, VICE PRESIDENT. RCE 217l9
BARRY L. MUNSON, PROJECT ENGINEER, RCE 40980
FREDERICK F. BRONSON, CHIEF OF SURVEYS, LS 5085
DELBERT C. DANIELS, CHIEF OF MAPPING, LS 3351
Site: 3317 Cadencia St., La Costa
Carlsbad, CA
To whom it may concern:
I am addressing the following numbers corresponding to the
numbers on letter of August 3, 1993 from David Hauser, City.of
Car lsbad :
3. The winter rains have reportedly caused additional seepage
damage after the installation of the subdrains and before the
.roof was placed to reduce water damage (27,000 gal. would fall
on the subject roof during a 100 year storm).
4. & 5. It is my opinion from review of plans, existing drains,
and my experience of subsoil conditions in the area, that the
fractured rock subsoil conditions allows passage of underground
seepage water to bypass the drainway and hydrostatically rise
into the sandbed under the house slab. Reducing the continued
absorption by roofing has,decreased the added underground flow to
an acceptable amount. The unsurfaced slab allows percolation outside the living area.
6. In the event that the roof structure is required to be
removed and an alternative method is required to alleviate the
problem, the following recommendations are secondarily suggested:
An 8'2 deep french drain with a waterproof curtain (mirradrain, Encadrain or equal) on the house side be constructed between the
house and property line wall to intercept and remove seepage from
the strata adjacent and upstream from the house slab.
The cost of saw-cutting the slab, excavating the trench in rock
subgrade and constructing the drain is estimated to cost approximately $15,000. Cost of removing the roof and unpermitted
walls would be another $15,000. Permits for a 'French Drain'' over
3' deep through "State Water Quality Control Board". may be
impossible.
Surveys and plans to apply for all required permits would cost
approximately $8,000 if accomplished by an engineer.
RECEIVED
AUO 2 6 I993
PlANNlNO DEW. CITY OF CARUBAD 0
TEL. (619) 743-8808 FAX (619) 743-7466
In summary: Since there is no way of guaranteeing that any
alternative method would protect the house from unusual an8
nnpredictable underground seepage, and since the owner has found
a way to eliminate the problem that is proven and, acceptable to
both him and his neighbors, I would recommend that the "anusual
circumstances" be recognized by the planning commission or
council and approve the variance.
Property Development Engineers,
John E. Vernon
RCE 21121, GE 858
Exp. 9/30/93
Inc .