Design work starts on the Coon Rapids dam project

The Coon Rapids Dam

The Coon Rapids Dam

Design and engineering work has started on the project to replace the existing Coon Rapids Dam.The 2011 Minnesota Legislature approved $16 million as part of a state bonding bill signed by Gov. Mark Dayton to reconstruct the Coon Rapids Dam to make it a more effective Asian carp barrier.

The Minnesota Department of Natural Resources (DNR) developed a request for proposal (RFP) for the design and engineering work and from the responses, the state agency has selected Stanley Consultants, Minneapolis.

According to Jason Boyle, state dam safety engineer with the DNR, the contract cost is $895,573, which will be taken from the bonding money.

The contract includes  project design and engineering as well as construction oversight, Boyle said

“We met with Stanley Consultants on the project two weeks ago and the consultant has started work,” he said.

The design and engineering phase is scheduled to take place this year with bidding scheduled in January 2013 and the reconstruction project to be built in 2013 and 2014, he said.

There will be two contracts – one for the reconstruction of the dam itself and the other for the new gates, Boyle said.

And the DNR will be moving forward on the gates project in a short period of time, he said.

“We will be asking for proposals on the new gates soon,” Boyle said.

Cost is factor on the type of gates that will be chosen, he said.

But ordering the new gates will be done in tandem with the design and engineering work, not after it is completed, because of the time it will take to have the new gates ready, according to Boyle.

“The gates will have to be fabricated,” Boyle said.

Stanley Consultants has worked with the Three Rivers Park District, which owns and operates the dam, in the past, he said.

Indeed, Stanley Consultant, working for the park district, presented a plan to fix the dam in early 2011 to a commission that had been set up to consider the dam’s future.

The estimated cost of $16 million in the Stanley proposal formed the basis for the state bonding bill allocation.

Stanley Consultants had been hired by the park district to evaluate the effectiveness of the dam to keep invasive fish species, like the Asian carp, from moving upstream.

The proposal it presented last year would replace the rubber gates presently in place at the dam with hydraulic or pneumatic gates that pass water over the top.

That would be an ideal fish barrier and would make the dam 99 percent effective as a barrier to invasive fish species, Marty Weber, an engineer with Stanley Consultants told the Coon Rapids Regional Dam Commission last year.

The commission had been set up by the 2010 Legislature to make recommendations on a repair project and also on the future ownership of the dam.

A joint powers agreement signed by the Three Rivers Park District and the DNR earlier this year has paved the way for the dam reconstruction project.

Under the agreement, the DNR will rehabilitate and manage the dam, while the park district remains responsible for routine maintenance and day-to-day operations of the dam as well as ownership.

Besides the new gates, the reconstruction project will repair a scour hole found in the concrete apron of the dam during a routine inspection in late 2010.

Still to be determined is whether the recreational pool will be kept at its summer level during construction, according to Boyle.

“There would be a great benefit in keeping the pool at it summer level during construction as a carp barrier, but there are some negatives as it will cost more,” Boyle said.

But in February, the DNR asked the park district to raise the six-mile recreational pool above the dam to its normal summer level beginning on or about Feb. 20. That does not normally happen until the beginning of May.

According to Boyle, the action was requested because Asian carp pose a significant threat to aquatic habitat in the Mississippi River and raising the water level in the pool behind the Coon Rapids Dam over the winter would make the dam a more effective fish barrier.

It was reported earlier this year that DNA from the invasive silver carp has been found above the Coon Rapids Dam.

This week the park district announced that the current pool level behind the dam is less than a half-foot below normal summer level.

And it will now be raising the pool the remaining few tenths of a foot to its normal summer level of 830.1, the park district states in its latest Coon Rapids Dam update.

The Coon Rapids Dam was built in 1913 by Northern States Power (NSP) Co. to generate hydroelectric power. When power generation stopped in the 1960s, NSP donated the dam and surrounding land on both sides of the river to the park district.

Anoka County now owns all the park property on the Anoka County side of the dam.

Peter Bodley is at peter.bodley@ecm-inc.com


  • Can’t Be Fooled

    I really question if this is about stopping Asian Carp or finding an excuse to secure funding to repair a dam that would have to be removed due to structural problems and protecting the property values of those along the reservoir the dam creates. Those believing that the dam will stop Asian Carp migration are in for a BIG disappointment.

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