DOWNTOWN — It isn’t a sleek new office complex or colorful parking garage, but there’s something worth celebrating about the completion of a relatively unglamorous sewer system — the people performing dirty jobs.

That’s exactly what a group of city officials did on Thursday when they gathered at the former Rand Corp. site on Ocean Avenue to rejoice in the conclusion of a relief sewer project, taking a peek at the system located three stories underground.

“We don’t always get together to celebrate the opening of sewer lines,” said Councilman Kevin McKeown, who brought a new plunger to commemorate the event. “They are underground, we don’t see them, we don’t think about them, but they are just as important to the functioning of the city as many of the other things we see above ground everyday and appreciate.”

The estimated $12 million project — an interdepartmental effort that involved Public Works, Finance and Housing and Economic Development — came more than 15 years after the Northridge Earthquake hit, which severely damaged the 1950s era sewer main below Colorado and Ocean avenues beyond repair.

Damages sustained from the 1994 natural disaster prompted City Hall to receive funding from the Federal Emergency Management Agency to begin repairing and replacing more than 80 percent of the 125 miles of sewer lines in Santa Monica, giving about $6 million to the Colorado Ocean Relief Sewer Project. Approximately $6 million more for the project came from AB1600 funds, which are fees associated with new development.

The relief sewer project is the last piece of the program, said Lee Swain, the director of Public Works. More than 66 percent of wastewater in the city goes through the main, including from the Holiday Inn and Sears.

The new system consists of a 108-inch-diameter inverted siphon that contains two, 42-inch and one 18-inch High Density Polyethylene carrier pipes, replacing the original 30-inch diameter main which is still in place and will be used as a backup. The sewer lines sit below the Holiday Inn on Colorado Avenue and the I-10 Freeway.

Greg de Vinck, a civil engineer with City Hall, said the 18-inch main will be in use most of the time and once it reaches capacity, which should happen every day, the extra flow will go to one of the 42-inch lines.

The inverted siphon functions to allow gravity to maintain the flow of wastewater to go downhill under the freeway and push sewage uphill on the other end, eliminating the need for a pumping station.

Swain said that there should be no issues with capacity and maintenance with the new system.

The project came within budget and completed about two months ahead of schedule.

The dirt lot that served as a construction staging site for the work below is slated to serve as a parking lot for when Cirque du Soleil comes to town in September. The lot will later be transformed into the Palisades Garden Walk, a four-to-six acre park.

A 25-year veteran of public works, Swain said that most people in the community do not understand the functions of the department and the services it provides.

“When we turn on the water fountain, we expect water to come out and when we flush the toilet, we expect that to be taken care of some how,” he said. “A lot of what we do in public works is take care of the basic quality of life needs.”

melodyh@smdp.com