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5-Mil Storage Tank - Project History

Backbone Improvement Program

5-Million Gallon Storage Tank Project - Las Virgenes Reservoir

(November 17, 2015)

The 5-Million Gallon Storage Tank is completed.  The new tank was presented to residents on Saturday, November 14 at an open house where guests could take self-guided tours of the 5-million gallon tank, walk the main dam and have a tour of the Westlake Filtration Plant.  More than a hundred local residents spent the morning touring the facilities, enjoying the weather, the views, and a complementary hot dog and beverage.

A group of people stands near a large round structure, listening to someone speak. They appear to be having a meeting or tour.

(Updated July 24, 2015)

The heavy construction phase of the project is complete; work continues on irrigation and landscaping at the site.

A hillside with houses and vegetation, set against a mountainous backdrop under a partly cloudy sky.
A large cylindrical structure in a hilly, forested landscape under a clear sky.

(Updated June 16, 2015)

The 5-million gallon tank construction project is in its final phases. Gutters and downspouts are yet to be installed, landscape work continues and various “cleanup” tasks remain.

Since the last update, the tank has been filled and passed its leak test; it must now be drained (the water will be returned to the reservoir) and pass final approvals before being placed into service. Some control equipment installation and electrical work is slated for completion in the next two weeks.

A round green structure near a reflective body of water, with hills in the background.

(Updated June 2, 2015)

Workers assemble the intricate plumbing between the Westlake Filtration Plant and the new 5-million Gallon tank. Paint is also being applied to the top of the tank, and landscaping is being installed adjacent to the site.  

Construction workers in safety gear handling a large concrete pipe at a worksite with equipment nearby.
Large cylindrical structure near a lake, with hills in the background and vehicles parked beside it.

(Updated April 21, 2015)

Work continues on the tank’s interior and on its control systems.

Painting the exterior is scheduled to begin during the week of April 27.

Large round structure under construction near a body of water, with vehicles and construction equipment around it.

(Updated March 24, 2015)

Work continues installing baffles and telemetry on the inside of the tank. A temporary plastic wrapping protects the new concrete coating on the exterior.

The new waterlines are undergoing pressure tests.

A large cylindrical structure near water with a mountainous backdrop reflects in the calm lake.
Underground construction site with large pipes and valves in a sandy excavation area.

Photo shows some of the complex pipeline systems being installed to connect the new tank to the Westlake Filtration Plant. When complete, these lines will be covered and paved over.

(Updated February 24, 2015)

A circular structure under construction near a body of water, with hills in the background.
A large cylindrical structure by a lake, surrounded by construction equipment, with a forested hill in the background.
A large cylindrical structure near a body of water, with construction equipment and greenery in the background.
A circular structure under construction near a body of water, with hills in the background.
A large cylindrical structure by a lake, surrounded by construction equipment, with a forested hill in the background.
A large cylindrical structure near a body of water, with construction equipment and greenery in the background.

A mobile construction tower applies the first layer of concrete coating material to protect the pre-stress cables surrounding the tank.

(Updated February 19, 2015)

A large industrial structure with a tall drilling rig beside an unfinished building, with clear skies in the background.

Installation tower circles the tank, wrapping it with thick steel cables, adding strength to the structure. After the pre-stress cables are installed, they will be coated with concrete; which will later be painted.

A person in safety gear examines a textured concrete wall.

A workman demonstrates the 7/8 – inch diameter of the cables and how closely they are placed.

(Updated February 10, 2015)

Industrial site with large circular tank, vehicles, and equipment near a body of water, surrounded by hills.

The temporary tower structure circles the tank, preparing it for the installation of pre-stressing cables.

Worker directing concrete from a mixer truck into a trench at a construction site.

Workers continue installing the inlet/outlet pipelines that run between the new tank and
the Filtration Plant. Here, slurry is being applied to cover and protect the new pipelines.

(Updated February 5, 2015)

Equipment is now in place to wrap the tank with pre-stressing wire and apply the concrete layers between wraps.  The wire wrapping adds significant strength to the tank structure.  When complete, the tall installation structure will be removed. 

(Updated January 13, 2015) 

Construction site with a large concrete structure, cranes, and equipment, set against a backdrop of hills and reflective water.

With the tank roof now in place, workers are preparing to wrap the exterior walls with cables which will add to its strength. 

A large concrete pipe partially buried in a dug-out trench, supported by wooden stakes.

Progress also continues on the pipelines that will convey water to and from the tank.

(Updated December 26, 2014) 

May contain: arch, architecture, outdoors, water, transportation, truck, vehicle, and person

Second Roof Pour – December 22, 2014

Concrete for the second half of the roof was poured through the day on Tuesday, December 22. Workers and concrete pumping equipment install the roof on the 5-million gallon tank at Las Virgenes Reservoir. 

(Updated December 10, 2014) 

Construction site with cranes near a reservoir, hills in the background, and reflections on the water.

View of the tank from across the reservoir.  The two mechanical arms (blue / yellow) on either side are the "snorkels" that pump the concrete from the ground to the roof.   

Concrete mixer truck and machinery at a construction site with workers on a scaffold.

Here is a concrete truck filling the "snorkel" machine that will pump the concrete to the top of the tank.  

Construction workers pouring and leveling concrete on a rebar grid, wearing safety gear.

Crews working with the "snorkel" as concrete pumps into the rebar of the tank's roof.  

Construction workers pouring concrete on a circular structure near a body of water, using a large green boom pump.

Wide angle view of the tank's roof.

A construction worker smoothing concrete on a large outdoor site, wearing safety gear, with rebar and hills in the background.

Crew smoothing and finishing the concrete on the tank's roof. 

(Updated December 3, 2014)

Heavy Construction Day Rescheduled to December 10

Due to weather, the "Heavy Construction Day" for the 5-Million Gallon Tank Project at Las Virgenes Reservoir in Westlake Village has been rescheduled to Wednesday, December 10.

Construction activity will begin at 7 a.m. with concrete deliveries being made though much of the day.

Additional traffic safety measures will be in place.  Please drive with caution.

Click here to see the letter mailed to Three Springs residents.Click here to view Traffic Safety Plan.

(Updated December 1, 2014)

Heavy Construction Day Rescheduled to December 4

Due to weather, the "Heavy Construction Day" for the 5-Million Gallon Tank Project at Las Virgenes Reservoir in Westlake Village has been rescheduled to Thursday, December 4.

Construction activity will begin at 7 a.m. with concrete deliveries being made though much of the day.

Additional traffic safety measures will be in place.  Please drive with caution.

Click link above to see the letter mailed to Three Springs residents. 

Click link above to view Traffic Safety Plan. 

(Updated November 24, 2014)

  • Or to view a video of the time lapse at a slower pace from February 28 to August 7, 2014 and the 18 blasting events. Your browser will be redirected to YouTube.             (mailed 4/15/2014)                                                       Updates will be posted periodically or you can sign-up for and select Construction Updates.