PORTLAND — A long-planned project to replace the bottom of the Deering Oaks pond is underway, which means there will be no ice skating this winter.

Troy Moon, the city’s environmental programs manager, on Nov. 19 said the $1.1 million project will make it easier for city crews to clean the bottom bi-annually. The job is funded through a $611,000 federal Environmental Protection Agency grant received in 2012 and $500,000 allocated in the 2013 city capital improvements budget.

The work to place concrete “fingers,” as Moon called them, and gravel on the bottom of the pond was modified after some objections from people concerned about how it would affect the habitat for ducks.

A significant change to the plan centers on the ravine area, where Moon said vegetation and landscaping will be added to prevent erosion, improve the appearance and enhance the wildlife habitat.

“We think it is a sound project, well designed,” Moon said.

He said replacing portions of the 3.5-acre man-made pond is expected to be done by March 31, 2016. Landscaping in the ravine will be done in May and June.

City-based Woodard & Curran was hired to study the pond conditions and how best to maintain it. The company initially recommended that concrete and gravel replace the silt bottom.

That plan drew objections from a group called Save the Deering Oaks Ducks, and a planned Sept. 17 project presentation in front of the City Council’s Transportation, Sustainability & Energy Committee was postponed.

Two months later, the revised plan, with work on the ravine, was endorsed by the committee.  The landscaping was expected to add $25,000 to the overall cost. Annual maintenance costs once work is complete were estimated at $59,000. Moon said those estimates have not changed.

The pond was last dredged in 2010, according to the study, when about six tons of accumulated silt was removed. Moon said the dirt being removed now by Gorham-based contractor RJ Grondin is the company’s responsibility.

Deering Oaks Park encompasses 55 acres between Deering and Forest avenues, and was acquired by the city about 125 years ago. The pond was created after sewer construction on State Street led to damming nearby tidal flats, according to the Woodard & Curran report. Pond water sources now include stormwater outflows, groundwater, and some water from the Portland Water District.

In November 2014, former Public Services Director Mike Bobinsky said the elimination of a combined sewer overflow in 2008 diverted wastewater to the Portland Water District treatment plant near East End Beach and enhanced pond water quality, but the pond remains vulnerable to overflows from the Deering Avenue area.

David Harry can be reached at 781-3661 ext. 110 or dharry@theforecaster.net. Follow him on Twitter: @DavidHarry8.

Crews from contractor RJ Grondin excavate sections of the pond at Deering Oaks Park in Portland on Nov. 18. Work to improve the pond bottom will continue through March 2016.