Ann Arbor considering options for responding to DEQ order to fix Argo Dam problems

Ann Arbor officials are working to respond to an order from the Michigan Department of Environmental Quality that calls the condition of Argo Dam a significant public risk.

The DEQ sent a certified letter to City Administrator Roger Fraser, demanding the city take action by certain deadlines to address concerns about the city-owned dam on the Huron River north of downtown Ann Arbor.

"Our charge is to ensure the safety of dams," said Byron Lane, chief of the DEQ's Dam Safety Program in Lansing. "It's of enough concern that we felt it was time we issue the order to make sure it gets done in a timely fashion."

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The DEQ's letter to the city is the latest chapter in a more than year-long contentious debate over the fate of the Argo Dam. Those who advocate for its removal say the dam is costly to maintain and poses environmental hazards, while those who support keeping it tout its benefits to recreational activity on the Huron River.

The city now has until Nov. 1 to completely shut off the flow from Argo Dam's impoundment to the headrace, a 1,500-foot stretch of water that canoeists and kayakers use to bypass Argo Dam. The DEQ wants the headrace dewatered so the city can address lingering concerns with the embankment that separates it from the Huron River.

DEQ officials fear a breach of the embankment could send a rush of water to the surrounding area and endanger anything in its path.

"This is a pretty popular stretch of stream," Lane said. "There's canoeing, there's parks right along there, so if you have a surge of water come through, and you have a wall of water coming down there, that would pose a danger to anyone who's in that area and any property."

City staff is preparing a series of options that will be presented to the Ann Arbor City Council at 5:45 p.m. Sept. 8. The working session at city hall will take place in advance of the regularly scheduled council meeting at 7 p.m.

"It seems the state wants an answer on the embankment," said City Councilman Mike Anglin, D-5th Ward, who is in favor of preserving Argo Dam. "What they're asking us is to come back with a plan now."

The official order from the DEQ states the headrace is to remain dewatered until problems with the embankment have been corrected or the dam has been removed. The agency also is mandating the city continue monitoring seepage emanating from the embankment at least monthly.

"We want them to address the deficiencies with the dam, and it's up to them how they want to do it," Lane said. "It may mean repairing the toe drains and removing all the trees, or they can remove the dam. In our mind, it's their call."

The DEQ is asking the city to complete an evaluation of its options to address the deficiencies by April 30, 2010. If the city decides to keep the dam in place, it has until Dec. 31, 2010, to correct the embankment problems. If the city decides to remove the dam, it must do so by Dec. 31, 2012.

The DEQ also has set a deadline of Feb. 1, 2011, for the city to complete engineering designs for the removal if it goes that route.

The Argo Dam, built in 1920 and last renovated in 1972, is regulated by the state Natural Resources and Environmental Protection Act of 1994. The DEQ says the dam is classified as a "high hazard potential dam," which means its failure could cause serious damage to surrounding homes, buildings, public utilities, highways and railroads, and potentially endanger human lives.

In a dam safety inspection report from Dec. 19, 2001, prepared by the DEQ's Land and Water Management Division, the headrace embankment was listed in "poor condition" due to seepage of water through the earthen embankment and extensive growth of trees and brush along the embankment. The city was asked to remove overhanging and dead trees by July 31, 2002, clean the dam's toe drains and monitor the seepage.

In another inspection dated Sept. 30, 2004, the condition of the embankment was found to have worsened. The city was directed to immediately repair the toe drains and remove some trees. An inspection dated Sept. 12, 2007, says the embankment still was in poor condition.

The DEQ claims the city still hasn't addressed the problems.

Anglin thinks it's feasible - though it could cost hundreds of thousands of dollars - to drain the headrace, make improvements, and then restore the water flow. Anglin said he prefers that solution because it would keep Argo Dam in operation and keep Argo Pond open for canoeists and kayakers.

About 18,000 canoe and kayal rentals are made annually at the Argo Pond location, representing about half of rentals at the city's two livery locations. Some city officials think canoe and kayak rentals would actually go up if the dam is removed because many people would prefer a riverine trip to a pond paddle.

The city's Parks Advisory Commission recently voted 5-4 to recommend keeping the dam in place, but Chairman Scott Rosencrans says it should close. While the dam once served as a source of generating hydroelectric power, he points out its only purpose today is recreational activity.

"I believe that there are a lot of benefits involved with the removal of Argo Dam," Rosencrans said. "But my contention is we should only do that if we can facilitate the rowing community at other impoundments."

Rosencrans thinks rowers can be accommodated at other locations, including Gallup Park. And with Argo Dam closed, the city could save on maintenance costs and realize some potential environmental benefits.

The city operates two canoe and kayak liveries in the city - the one at Argo Pond and the one in Gallup Park. Rosencrans said the city makes about $400,000 a year in revenue at the two locations, generating a $65,000 net surplus after factoring in costs.

Photo captions: Crew teams practice Thursday afternoon on Argo Pond just above the Argo Dam on the Huron River, north of downtown Ann Arbor. Water flows through the Argo Dam on the Huron River in Ann Arbor on Thursday. Steve Pepple | AnnArbor.com

Ryan Stanton covers government for AnnArbor.com. Reach him at ryanstanton@annarbor.com or 734-623-2529.