Maintenance Work Brings Temporary Closings to Rec Area at Top of Kensico Dam

The recreation area on top of Kensico Dam will be closed intermittently for several weeks while contractors remove weeds and plants from the face of the dam, which will also be re-grouted to ensure the spaces between the stones are sealed and secure.  
The New York City Department of Environmental Protection says that, over time, weeds and plants have grown in the joints between the stones on the face of the 307-foot-high dam in Valhalla. The roadway on the dam is used by local residents for walking, jogging, in-line skating and bicycling.
The weeds and plants must be removed because they can allow water to trickle into the concrete joints between the stones, according to the NYC DEC.  That water can potentially damage the concrete joints and stone face when it freezes and expands.  To remove the weeds and plants, DEP will have specialized crews rappel down the face of the dam and apply herbicide starting this week.  Special care will be taken to ensure the herbicide does not enter the reservoir or negatively affect drinking water quality, according to the agency.
The herbicide must be applied while the weeds and plants are in bloom to kill the roots.  Each application of the herbicide will take one to two weeks.  The herbicide will be applied to the dam twice, with a week hiatus between each application.  DEP will re-grout the spaces between the stones once the weeds and plants are removed.
The recreation area is expected to be closed from 7 a.m. to 5 p.m., Monday through Friday, during the weeks when herbicide is being applied.  It will be reopened after 5 p.m. each day, and it will remain open during weekends and the weeklong hiatus between applications.  
The road will be barricaded and signs will be posted during the intermittent closures.  Westchester County’s park below the dam will remain open, but a small portion of it immediately adjacent to the dam will be closed while the work is happening.  
The recreation area atop Kensico Dam was reopened last year following a $42 million rehabilitation project at the dam, which is located about 3 miles north of White Plains in Valhalla.