TITLE
Recommendation to receive and file the report, "Elevation Changes in the City of Long Beach, November 2011 through April 2012." (Citywide)
DISCUSSION
The City of Long Beach, 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 November 2011 through April 2012. The LBGO survey includes the following areas: Civic Center, Central City, Alamitos Bay, Naples, Harbor District, and an offshore area encompassing the four oil islands.
The results of the six-month survey show that elevations were stable in the Civic Center, Central City, Alamitos Bay, Naples, and the offshore areas. The Harbor District remained stable except for two areas of minor elevation change. An elevation loss of up to 0.07 foot (0.8 inch) occurred on Pier S, while portions of Piers D, E, and T experienced an elevation rise of up to 0.09 foot (1.1 inch). Ongoing oil development activities are occurring in both of these areas. LBGO is taking steps to mitigate the minor variations in elevation. However, the elevation changes do fall within the range of historical fluctuations.
The LBGO survey uses a series of benchmarks to determine elevation changes. Studies by the Department's engineers and geologists show that the benchmarks may rise and fall 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 matter was reviewed by Deputy City Attorney Richard Anthony on September 13, 2012 and by Budget Management Officer Victoria Bell on September 10, 2012.
TIMING CONSIDERATIONS
City Council action on this matter is not time critical.
FISCAL IMPACT
There is no fiscal impact or local job impact associated with this action.
SUGGESTED ACTION
Approve recommendation.
Respectfully Submitted,
CHRISTOPHER J. GARNER
DIRECTOR OF LONG BEACH GAS AND OIL
APPROVED:
PATRICK H. WEST
CITY MANAGER