HomeMy WebLinkAboutAGENDA REPORT 1996 1002 CC REG ITEM 07EMEMORANDUM
To: Honorable City Council
From: Dirk Lovett, Assistant City Engineer
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Date: September 20, 1996 (Council Meeting 10 -2 -96) -
Subject: Consider abandonment of the storm drain design on Park Lane
South of Los Angeles Avenue
Background
On June 5, 1996 the City Council authorized the City Engineer to proceed
with the design of a storm drain that would collect water that currently
ponds at the south end of the paved improvements of Park Lane. The
purpose of the design was to conduct the nuisance water to an existing
storm drain in Los Angeles Avenue to the north. The design was
authorized as an attempt to immediately remediate an ongoing situation
that occurs at the south end of Park Lane following storms. The
preliminary estimate for the design, construction and construction
administration was $75,000.
As expressed in the June 5th report, this drainage problem would normally
be addressed and corrected when the property to the south is developed.
At that time a storm drain will be conducted southerly to the Arroyo Simi,
at an estimated cost of roughly $320,000, including design and
construction engineering. Because the date of that development is
unknown the City chose to try a more immediate solution to the ponding
problem.
Analysis
After
completion of the preliminary
hydraulic analysis of
the existing
pipe
in Los Angeles Avenue it was
determined that the pipe is already at
maximum capacity. The pipe flows
under pressure during a design storm.
Even
though the elevation of the Los Angeles Avenue pipe
is lower than
what
would be the Park Lane pipe,
the existing pressure in
the Los Angeles
0()(;()84
Avenue pipe would cause storm water to back out the proposed Park Lane
catch basin and into Park Lane.
Rather than undergo extensive and costly design and construction to either
upsize the Los Angeles Avenue pipe or run a second line parallel to it, cost
would more than double the currently proposed option, it is staff's
recommendation that the current design be abandoned. This action would
leave the seasonal ponding situation status quo until such time that the
property to the south is developed, at which time all improvements
necessary to correct the problem will be required of the developer.
Because this is a low volume street and ponding is only seasonal, in
isolated areas, an immediate solution is not deemed critical.
Conclusion
The Los Angeles Avenue storm drain is under capacity to receive
additional storm water from the proposed Park Lane drain. The nuisance
water problem on Park Lane is considered to be of a minor nature and will
be corrected, at some time in the future, by the development to the south.
The benefits to the City of upsizing the Los Angeles Avenue storm drain do
not appear to justify the extra costs.
Recommendation
It is recommended that the City Council abandon the storm drain design.
cc: chron
66.030