Portland city councilors have hit pause on a $1.1 million project to replace the mucky bottom of Deering Oaks Pond after some local residents suggested a more natural approach to improving water quality.

The city’s Department of Public Services was poised to solicit bids this fall on a project to remove the existing, muddy bottom of the popular pond and replace it with gravel bisected by corridors of concrete blocks. Those plans have prompted a broader discussion about the historic and high-profile landmark: Is Deering Oaks Pond just an urban pool with a pretty fountain, or could it be more of a natural, self-cleansing pond?

“We haven’t even considered the alternatives and that is what really bothers me about this,” said Amanda Martin, a local resident who made a counter-presentation to the city’s proposal during a meeting Wednesday night.

According to city staff, the gravel-and-concrete design would allow crews to access the pond’s interior with heavy equipment to annually clean up the leaves, trash and muck that accumulate on the pond floor. Those sediments, combined with duck droppings and pollution from storm runoff, contribute to water quality concerns in one of Portland’s most popular parks.

But members of the City Council’s Transportation, Sustainability and Energy Committee have halted the project, at least temporarily. During a meeting Wednesday night, committee members asked the city to explore other natural options – including wetlands plantings – around what is now essentially a man-made impoundment.

“I think we need to take a look at it through a different lens,” David Marshall, chairman of the committee and a District 2 councilor, said in an interview Thursday. “I don’t think going in and removing the bottom of the pond is the best thing that we could do.”

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CLEANING POND POSES CHALLENGES

A more natural approach could be a step back in time for the pond.

Old maps of Portland from the mid-1800s show that what is now Deering Oaks Pond was once marshland or tidal flats connected to Back Cove. Sea water filled the pond at high tides, and drained out at low tide.

The city created the pond sometime around 1880 by damming off the tidal flats while installing sewer lines under State Street. Various types of walls, fortified shorelines and pond bottoms have been added in the past 130-plus years.

Today, the 3.5-acre pond is designated as a “historic landscape” feature within Deering Oaks park, which is listed on the National Register of Historic Places. Visitors feed a community of ducks living in the “Duck House” that is perched each summer on a small island, while a nearby decorative fountain – the latest version of which was installed in 2006 – helps to circulate water in the pond.

In summer, Portlanders stroll around the pond or feed the ducks. During winter, the pond is popular with skaters. In 1996, the frozen pond became a backdrop for a scene in the movie “The Preacher’s Wife,” starring Whitney Houston and Denzel Washington.

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City officials insist the pond requires annual maintenance to reduce the buildup of sediments that can lead to algae blooms, foul-smelling water and potential health concerns.

The last major cleanup took place in 2010, when crews removed an estimated 4,000 cubic yards of muck – enough to fill two, two-story houses – from the bottom of the drained pond. Despite working for roughly a month, the crew was only able to clear about half of the pond. In 2006, an excavator that strayed too far into the muddy depression became stuck and had to be extracted.

“The issue is it is so soft that it takes a long time to do it, and it really is problematic for equipment to operate in those conditions,” said David Senus, project manager with Woodard & Curran, which worked with the Department of Public Services to develop the city’s proposal.

That’s why the city’s new proposal involves covering most of the pond bottom with a type of small gravel common in Maine. Pre-cast concrete blocks would also be laid in strips through the center of the pond and along several offshoots to provide heavy equipment with a more stable bottom to access the interior when the pond is drained annually.

Roughly one-half of the $1.1 million project would be financed with a grant from the U.S. Environmental Protection Agency, with the city contributing the rest.

Michael Bobinsky, director of public services for Portland, said the city and Woodard & Curran crafted a proposal that they believe fits within the budget, improves access to the pond for maintenance and will help improve water quality. The committee’s pause was unexpected, but Bobinsky said his staff will work to present other options during the next committee meeting.

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“We certainly respect and are intent on satisfying the committee’s concerns that this project is in the best interest of the city and in the best interest of water quality,” he said.

CREATE SELF-SUSTAINING SYSTEM?

Martin, who studies environmental sciences at the University of Southern Maine, suggested that replacing the muddy bottom with gravel could inadvertently remove the conditions that prompt ducks to feed and live at the pond seasonally. She also said reconfiguring the bottom, combined with regular disturbance, could create an opening for additional invasive species to move in. And, she said, the artificial bottom would have to be redone.

“In 20 years it is going to cost just as much money to do it again,” she said.

Instead of pushing forward with the city’s proposal, she urged councilors to spend money on a “green alternatives study” that would explore options to create a more self-sustaining system similar to a wetland rather than “an impounded fountain.” Possibilities include more native wetlands plantings around the edges, reducing the amount of impervious road surfaces within the park and floating plants that absorb contaminants from the water.

Some of Martin’s suggestions resonated with Councilor Jon Hinck, who supported the idea of exploring options “for restoring a more natural, regenerative environment there.” The big question, Hinck said, would be the cost comparison and whether the alternatives would affect the ducks, ice skating or other popular features of the pond.

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“It might be very difficult to do too much, but I would like the consultant and the city staff to examine the options,” Hinck said Thursday. “We have one proposal. Should we be considering other ideas?”

Anne Pringle, president of Friends of Deering Oaks, said her organization has been working with the city for decades to address the algae problem. They have tried numerous approaches, including dredging and using hay bails to absorb contaminants. But the reality is the pond needs annual maintenance.

“The Friends of Deering Oaks totally supports (the city’s) approach,” Pringle told the committee.

Bobinsky hopes to move forward with the project this fall – with construction to start this winter – but he will likely request an extension on the EPA grant just in case.

“I think we are all on the same page with regard to water quality improvement,” Bobinsky said. “It is helpful to hear the questions.”


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