Lake Delhi Dam reconstruction wins engineering award

DELHI - Six years ago when floodwaters destroyed the Lake Delhi dam, many of the residents in the small Delaware County community of Delhi - population 470 - feared the dam would never be rebuilt and the 400-acre lake it served would be lost forever.

But earlier this year, during a grand celebration, a new dam opened and the lake was reborn.

Now, the Muscatine-based engineering firm that designed the dam is getting its reward.

Stanley Consultants has been awarded the American Council of Engineering Companies of Iowa's Grand Conceptor, which recognizes engineering projects that demonstrate an exceptional degree of innovation, complexity, achievement and value. It is the top award in the state given each year as part of an engineering excellence competition, according to a news release from the company.

'This marks the first time in recent history that we've won the top award in the Iowa ACEC competition,” said Mary Jo Finchum, a spokeswoman for the company. 'In the past few years we've received multiple awards for local projects such as the Credit Island Lodge Restoration and the West Side Diversion Tunnel in Davenport, the Iowa City Wastewater Treatment Plant and the Fox River Bridge in Elgin, Ill.”

The Lake Delhi Dam's labyrinth spillway, the first of its kind in Iowa and one of the largest in the Midwest, can pass high volumes of water across a short distance without using mechanical gates or electrical systems. The accordion shaped spillway makes it possible, tripling its capacity to pass water as compared to a conventional spillway design, according to officials from Stanley Consultants, which also has offices in Cedar Rapids and Coralville.

It took only a few hours for the lake to empty on July 24, 2010, after the dam breached following heavy rains in the Maquoketa River watershed.

It took four years to secure funding and obtain permits, among other preparations, and two years to build the new dam.

During that time, all of Delaware County felt the economic impact caused by the loss of the lake. Property tax revenue plummeted, property values plunged, construction around the lake slowed to a stop, and income streams for local businesses who depended on the lake traffic dried up, according to company officials.

Momentum for the project picked up when more than 95 percent of Lake Delhi residents approved a $6 million bond referendum. Their willingness to contribute helped persuade the state and county to support the rebuilding effort with grants totaling $5 million and $3 million, respectively.

During the grand opening celebration in June, State Rep. Lee Hein, R-Monticello, said Lake Delhi residents earned the support of state government.

'You did everything the state asked, and you stayed with it,” he said.

Larry Burger, a trustee for the Lake Delhi Combined Recreational Facility and Water Quality District, said during the June ceremony he started coming to the lake in 1955 and thought the dam would never be rebuilt. He said real estate values, which tanked after the lake vanished, have rebounded.

Pat Colgan, a retired civil engineer and volunteer coordinator of the rebuild effort, said the rebuilt dam and spillway can safely accommodate a flow of 69,000 cubic feet per second - well more than twice the flow that caused the 2010 breach.

'I would say it's fail-safe short of an asteroid strike,” he said during the June ceremony.

Just months later, in October, the dam would be tested by the lake's fifth largest recorded flood.

Officials from Stanley Consultants said in a news release 'the automated gates performed flawlessly and the floodwater passed with no significant rise in the water level near the dam.”