The partnering efforts were recognized on18 March at the 2010 AGC 91st Annual Convention in Orlando, Fla.

“These awards acknowledge and encourage the fact that great builders must also be clear communicators and strong coordinators,” said Doug Pruitt, the president of the Associated General Contractors of America. “Finesse, patience and planning are as essential as concrete and steel for converting plans into reality.”

Pruitt said Flatiron was selected for the award because of its success building partnerships with government agencies and community groups to build support for their work replacing the dam’s crumbling outlet structure. Partnering with Flatiron were Santa Clara Valley Water District, tunnelling subcontractor Drill Tech Drilling and Shoring Inc., designer Jacobs Associates Engineers/Consultants and construction manager Hatch Mott MacDonald.

“It is a great honor to be recognized for this award on such a complex project. The client made a key decision to provide Flatiron full access to their technical designers during the entire pre-construction and construction phases,” said Richard Grabinski, Flatiron district manager. “Partnering was so successful because Flatiron was able to effectively plan and communicate with these important stakeholders. There now exists a seismically safe water supply system where before there was just a mountain.”

Flatiron worked to replace the deteriorating outlet structure for the 50-year-old Lenihan Dam, a 1000ft (304.8m) long earthen barrier holding water stored at the Lexington Reservoir located at the foot of the Santa Cruz Mountains. Surrounded by pristine wilderness, the trail system around the Lexington Reservoir is one of the most scenic in Northern California. The 2.5 mile-long reservoir is the second-largest reservoir under the Santa Clara Valley Water District’s authority, with a capacity of 19,044 acre-feet and a surface area of 412 acres. During the past few decades, the dam’s old outlet structure had deteriorated and a new outlet structure was required. Construction included a new 2000ft (609.6m), horseshoe-shaped tunnel 14ft (4.3m) wide by 13ft (4m) tall to house a 54-inch-diameter outlet pipe. A 37ft (11.3m) vertical shaft was also constructed down the backside of the dam that intersects with the tunnel.

The Lenihan Dam project included a significant amount of underground and confined space work with the tunnel excavation and the abandonment of the existing outlet pipe. With the partnership, this project was completed safely, under budget and ahead of schedule.