HomeMy WebLinkAboutCC AG PKT 2004-02-23 #O AGENDA REPORT
DATE: February 23, 2004
TO: Honorable Mayor and City Council
THRU: John B. Bahorski, City Manager
FROM: Douglas A. Dancs, P.E., Director of Public Works /City Engineer
SUBJECT: SAN GABRIEL RIVER DEBRIS BOOM, PROJECT NO. 50086
- FINAL REPORT RECEIVE AND FILE
SUMMARY OF REQUEST:
The proposed action will receive and file the final report for the design of the San Gabriel River
Debris Boom Project No. 50086 and authorize the City Manager to forward the report to the
County of Orange and County of Los Angeles watershed divisions.
BACKGROUND:
During the Fiscal Year 1999/2000, the City was fortunate to apply and receive a State budget
allocation within the California Coastal Conservancy budget for the City's Ocean Water Quality
Program. $300,000 has been budgeted in the 2001/2002 Capital Improvement Program for the
design, environmental, and administration portion of the proposed San Gabriel River Debris
Boom. The Engineering Division contracted with Moffatt and Nichol Engineers to prepare the
concept design and staff has been working with Los Angeles County Dept. of Public Works,
Orange County Public Facilities and Resources Department, and the City of Long Beach.
The San Gabriel River Debris Boom is a debris collection system designed to reduce debris
flows and urban waste within the San Gabriel River watershed that ultimately are discharged at
the river mouth. The main goal of the project was to propose the best option for decreasing the
debris load at the mouth of the San Gabriel River, and in particular to decrease the quantity that
is washed up onto Seal Beach. Currently, the County of Los Angeles Watershed Division has an
experimental debris net at the confluence of the San Gabriel River and Coyote Creek and is
monitoring its performance.
On March 11, 2002, the City Council received and filed the presented information on the
preliminary design report for new debris boom using a design of cylindrical buoys and a specific
net material. The City's consultant Moffatt and Nichol Engineers then conducted hydraulic
studies at the Canadian Hydraulics Center in Ottawa, Canada. Initial studies were completed in
January 2003, with additional testing of the most promising alternative completed in April 2003.
The concepts and results were presented to the City of Long Beach, and Orange and Los Angeles
County Public Works Staff.
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Moffatt and Nichol Engineers developed preliminary design drawings and specifications for a
prototype of the most promising alternative. The design was developed for installation at the site
of the present experimental net design installed by Los Angeles County Public Works on Coyote
Creek, just north of its confluence with the San Gabriel River. However, the design could be
adapted to other portions of the channels relatively easily.
Staff has now concluded its oringinal project scope with the grant received from the California
Coastal Conservancy. As originally planned, it is now appropriate to forward a final submittal
consisting of the the design, model testing and presentations to County of Orange and County of
Los Angeles for their agencies to pursue the construction of these systems. A copy will be sent
to the California Coastal Conservancy as well.
It should be noted that, as part of the agency review process, concern was raised by swift water
rescue personnel regarding public safety issues associated with implementation of the net in
these channels. Their main concern was the potential for either a victim or rescuer to be pinned
against the net during a storm flow event.
The final report is quite large, with over 250 pages of color photos and drawings and is on file
with the City Clerk's office.
FISCAL IMPACT:
Funds in the amount of $300,000 are currently programmed in the approved Capital
Improvement Program from the State's California Coastal Conservancy budget. This amount
includes the design, environmental, and administration portion. Any remaining funds will be
returned to the State.
RECOMMENDATION:
It is recommended that the City Council receive and file the final report for the design of the San
Gabriel River Debris Boom Project No. 50086 and authorize the City Manager to forward the
report to the County of Orange and County of Los Angeles Watershed Divisions.
Prepared By: Conc l
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Mark K. Vukojevic, P.E. Douglas A. Dancs, P.E.
Deputy City Engineer Director Public Works /City Engineer
NO 1' • P APPROV 'r•
Jo pit ahorski, ity Manager
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