TITLE
Recommendation to receive and file the report, "Elevation Changes in the City of Long Beach, May 2009 through October 2009." (Citywide)
DISCUSSION
The City of Long Beach (City), through the Long Beach Gas and Oil Department (LBGO), supervises oil production and subsidence control operations in the Wilmington Oil Field. LBGO conducts elevation surveys every six months to monitor elevation changes in the oil fields and adjacent City areas. This report focuses on elevation changes that have occurred from May 2009 through October 2009. The LBGO survey includes the following areas: Civic Center, Central City, Alamitos Bay, Naples, Harbor District, and an offshore area encompassing the four offshore oil islands.
The results of the six-month survey show that elevations were stable in the Civic Center, Central City, Alamitos Bay, Naples, and offshore areas. The Harbor District was stable except for the area surrounding the Port of Long Beach Middle Harbor Redevelopment Project, south of Ocean Boulevard. With the abandonment of Pier E oil facilities, an elevation loss of up to 0.080 feet (0.96 inches) occurred in the vicinity of Piers D, E, and T. There is no reason for concern as LBGO is mitigating the minor elevation change in the area by increasing and realigning water injection with several replacement water injection wells.
The LBGO survey uses a series of benchmarks to determine elevation changes. Studies by the Department's engineers and geologists may show the benchmarks are rising or falling in such a manner as to make a survey either optimistic (slightly up in elevation) or pessimistic (slightly down in elevation). These changes in elevations may be associated with tidal cycles, temperature changes, and/or deep earth tectonic changes or re-pressuring operations. Surface elevations in a rebounded area can be expected to fluctuate under changing water flood conditions.
This item was reviewed by Deputy City Attorney Richard F. Anthony on March 1,2010 and by Budget Management Officer Victoria Bell on March 10,2010.
TIMING CONSIDERATIONS
City Council action on this matter is not time critical.
FISCAL IMPACT
There is no fiscal impact associated with this action.
SUGGESTED ACTION
Approve recommendation.
Respectfully Submitted,
CHRISTOPHER J. GARNER
DIRECTOR OF LONG BEACH GAS AND OIL
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PATRICK H. WEST |
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CITY MANAGER |