CSPE Floating Cover System For 67 Million Gallon Potable Water Reservoir

LOCATION:  North Beverly Drive, Los Angeles, California
TIMEFRAME: June 2016 to October 2016
SCOPE OF WORK: 
Fabricate and installation of a 45 mil weight tensioned CSPE floating cover, rainwater removal system and various cover appurtenances.  Remove and construct reservoir floor asphalt liner and asphalt concrete pavement on reservoir access ramp.    

PROJECT PARTNERS: Los Angeles Dept. of Water & Power, Layfield Environmental Containment



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Background Information and Challenge

This was a larger 67 million gallon open top reservoir located minutes from the downtown Beverly Hills, California.  The project was impacted by traffic and urban density.  The construction site had poor site access and limited space to work.  Maintaining a safe worksite based on the site access problems was also an important challenge and priority.  The CSPE floating cover needed to be prefabricated in Layfield’s San Diego fabrication plant and all material shipments needed to be tightly coordinated and scheduled. 

Solution

To address the congested site conditions and limited workspace access, the project required an experienced and highly quality project management and installation team.  The reservoir was designed with a weight tensioned cover system made of 45 mil CSPE 3-ply special green/green material.  This cover design allowed it to rise and fall with the change in the freeboard water level.  With this design, the excess slack in the cover is pulled down by sand tube weights located within the rainwater collection troughs as the water level increases.  The define sump design ensures the cover is kept in a tensioned position at all times.  The floating cover was equipped with the following appurtenances.
 

  • Seventeen access hatches.

  • Six 12’’ diameter floating cover vents.

  • Five rainwater pump towers with 3’’ submersible pumps that automatically remove rainwater from the top of the cover.

  • Five Storage Rafts that support the fiberglass grating and davit crane assembly for each pump tower.

  • Five textured walkway surfaces that are located from the top of slope and extend to the rainwater collection troughs.

  • One 210LF air baffle on the underside of the floating cover located 202’-6’’ south of the inlet spillway.

Results

There was excellent communication and cooperation between the project owner, engineers and floating cover installation contractor.  The project was completed on time and on budget while maintaining strict safety standards.