Army Corps Nears Completion of Final Flood Plan Report for Mamaroneck

By Nina Recio Cuddy

The Local Summit of Larchmont/Mamaroneck launched its monthly breakfast speakers’ program of the
2016-2017 season with a presentation about the long-awaited flood remediation report being finalized by the Army Corps of Engineers for the Mamaroneck community. Flooding is an ever-present concern in Mamaroneck and guest speakers, Tony Gelber, Chairman of the local Flood Mitigation Committee, and Richard Slingerland, Village Manager for the Village of Mamaroneck, were tasked with explaining its causes and proposed remedies.

Gelber, who described Mamaroneck as the “New Orleans of Westchester County,” traced his involvement with the Flood Mitigation Committee to an encounter with State Senator George Latimer shortly after Hurricane Irene struck the area in 2011. Gelber, who had experienced flooding at his upstate New York property, was examining the Mamaroneck River that had backed up on both sides. Latimer also was at the site and, following a discussion regarding the flooding, suggested to Gelber that he consider joining the Flood Mitigation Committee.

According to Gelber, Mamaroneck is a “watershed” into which about 24 square miles of eastern Westchester County drain and the water eventually winds up in Mamaroneck’s Columbus Park. Gelber reported that there have been approximately 20-25 floods in Mamaroneck since 1880, punctuated by a massive flood every 4-5 years. Interestingly, Gelber said that for a period of about 20 years from 1984-2004, there was almost no flooding. This relative tranquility was broken by floods in 2004, 2005, 2007, 2009 and 2011.

According to Gelber, the flood of 2007 was “the flood of record” because it was the most flood water Mamaroneck has ever experienced with about about 5,000 cubic feet per second flowing down the Mamaroneck River. Slingerland described the 2007 storm as a “hundred year storm.”

Gelber recognized that controlling and managing the flow of that sheer amount of water is a “phenomenally difficult task”, but it is the task that the Army Corps of Engineers has undertaken. He explained that the goal of the Army Corps is to devise a means by which the water, which comes from such areas as White Plains, Rye, Westchester County Airport and the corridor along I-287 (the Cross Westchester Expressway), can be more quickly and efficiently directed into the Long Island Sound. The Corps is specifically looking at the
water that floods the Mamaroneck and Sheldrake Rivers and, according to Gelber, “the Corps has been continually engaged with the Village on this project.” The plan will include the installation of walls at certain locations and the removal of obstructions along the rivers.

Gelber stated that the Committee has been concerned not only with flood control but also with the aesthetics of a flood control plan so that the end product will protect the Village in an “environmentally sensitive” manner and not be incongruous with the appearance of the Village. He indicated that there have been assurances from the Corps that they will restrict the height of the walls along the river banks. Additionally, according to Gelber, grant money has been sought by the Village to develop “river walks” at certain
locations.

Gelber provided the audience with a short history about the Flood Mitigation Committee, which he credits with being a forceful advocate for the community. According to Gelber, it was started in 2007 by community members Andrew Spatz and Peggy Jackson, both of whom had been victims of Mamaroneck floods. (Jackson is also a Local Summit board member.) Their hard work was applauded by Gelber, who also recognized the
important efforts of local officials, including Representative Nita Lowey, State Senator George Latimer, Town Supervisor Nancy Seligson, and County Board Legislator Catherine Parker, among others. Their collective efforts were successful in securing assistance from Washington for the proposed flood mitigation work in Mamaroneck.

Slingerland in his presentation described the project that has been proposed by the Army Corps. He said that the existing river walls are collapsing and that the Corps has proposed installing new channel banks that will widen and deepen the river. The banks will be reconstructed into a trapezoidal shape with sloped walls and a flat bottom. In addition, the Corps has proposed placing large rocks and planting heavy vegetation, thereby giving the appearance of “a vegetated river channel”. Old growth trees growing within the river will be removed as they obstruct the flow of flood water. Also, Slingerland informed the audience that the plan “includes the addition of a major culvert under the Jefferson Avenue parking lot so that flood waters can be directed out towards the Sound.”

Slingerland’s comments turned to the cost of the project. Slingerland put the price tag at approximately $80-82 million. Because the project is proposed under the National Economic Development Plan, the federal government will pick up 2/3 of the cost. Slingerland estimates that the Village’s responsibility will be approximately $7-9 million, matched by $7-9 million from the County and $13 million from the State. The balance will come from the federal government.

Slingerland also acknowledged the fear of some residents that property will be taken by eminent domain in order to achieve the remediation that is needed. This community concern has been discussed with the Corps, and the Corps responded that it is required by law to minimize any impacts on private property.

Slingerland also described the efforts that are regularly undertaken by the Village in coordination with the other local municipalities when heavy rains are forecasted, and complimented the other municipalities for their cooperation. Slingerland stated the Corps has helped the Village to develop preparations for heavy rainfalls. These efforts include clearing the grates in the rivers and brooks, lowering the dam in Larchmont and ensuring all river openings are cleared. Although these efforts are helpful, Slingerland noted that they alone are not sufficient if there is 4-4.5 inches of rain since that amount of rain will generate a flooding
problem, especially if the ground is wet.

The final draft of the Corps’ plan will be submitted by December 2016 and the final Environmental Impact Statement review will be in March 2017. The final record of decision should be in June 2017, but there is no expectation of shovels in the ground before 2019.

This breakfast forum was hosted by the Larchmont/Mamaroneck Local Summit, an informal community council that seeks to make life better for all in the tri-municipal area. Its monthly meetings are held at the Nautilus Diner in Mamaroneck Diner at 7:45 a.m., usually on the third Tuesday of the month. The next
meeting will take place on October 18 and will explore how LMC-TV serves the community.