Community and Trustees Consider Stormwater Retention Project at Harcourt Woods

Changes to the Scarsdale landscape at George Field and Cooper Green are just two phases of the comprehensive stormwater management plan in store for the village. The original $3,150,000 plan called for large detention basins at George Field and Cooper Green as well as cleaning and lining the watercourse along Cambridge and the Post Roads, another detention pond at 2 Murray Hill Road, work on the high school parking lot and the rechannelization of Harcourt Woods.

However, the engineer's original vision had to be revised when the property at 2 Murray Hill could not be purchased for a pond and Westchester County regulations prevented the Village from moving fill from the excavations at George Field and Cooper Green to raise the elevation of the high school parking lot. Furthermore, though they considered using a portion of Harcourt Woods for water retention, they found that the area had unfavorable hydraulics and would not be an efficient place to store water.

Therefore, with funds already approved for the project, the engineers have revised their plans and now propose to focus on

Harcourt Woods and Brewster Road at Scarsdale High School. Engineer Rob DeGiorgio from Dvirka and Bartilucci presented the revised plans to trustees and residents at a meeting of the Scarsdale Municipal Service Committee on Wednesday night, October 3. The meeting drew scores of Fox Meadow residents who were concerned about the potential loss of trees and the effect of changes to the watercourse on their own homes.

 

DeGiorgio explained that Fox Meadow Brook now meanders through Harcourt woods in a hooked path that may have been diverted at an earlier time. The current stream bank encroaches on Scout Field and borders the high school tennis courts. The stream bank is eroding and there are many dead and dying trees in Harcourt Woods, which at some points obstruct the watercourse.

The plan is to restore the stream bank with a Gabion wall, which is a stone wall enclosed in mesh – that includes live plant stakes that will grow to form a vegetative front on the stream wall. The steep vertical walls of the stream would be softened and turns in the watercourse will be erased. This would facilitate the flow through the woods, prevent further erosion of the stream bank and protect tree roots along the watercourse. The stream will be bordered by “apron landscaping," a sediment trap will be installed and the bridge over the culvert in Harcourt Woods will be widened to five feet and improved.

Though the elevation of the parking lot at the high school could not be raised, new catch basins and drain piping will be installed on Brewster Road to send water downstream to Harcourt Woods. In addition, new curbing will be installed on Brewster Road and the sidewalk that runs along Brewster Road in front of the high school will be extended so that it runs all along the expanse of the back of the school. According to Trustee Kay Eisenman who heads the Municipal Services Committee, “Flooding will be mitigated in the high school parking lots through the diversion of stormwater from the westside of Brewster Road directly to the new sediment pond to be constructed as part of the revised Harcourt Woods Project. Stormwater currently runs across Brewster Road to the parking lots and into the Brewster Road open watercourse.”

The budget for the project is $950,000 and will be partially funded by Westchester County. If approved, the work will begin next summer.

Both the trustees and the residents had many questions about the project and it was clear that after witnessing the work at George Field and Cooper Green, there were concerns about the elimination of trees. Trustee Brodsky asked DeGiorgio to differentiate this project from George Field and Cooper Green and he explained that this was not another detention pond and that the landscape along Harcourt Road would not change.

Lena Crandall asked the trustees to bring in independent arborists to assess the health of the trees before removing them and said that she had walked the woods with three tree experts who had not seen hazardous trees on site. She also inquired about the size of the equipment that would be needed to do the work and urged the Village to use small equipment that would not destroy the existing landscape.

Dan Hochvert asked the village to use this opportunity to remove invasive Japanese knotwood that grows rapidly, falls into

the watercourse and spreads. Fox Meadow residents expressed concern that the water diversion on Brewster Road could cause flooding in their homes.

Deb Pekarek questioned the project from a cost/benefit perspective and asked why they project will cost $950,000, which is as much as the detention pond on George Field. She asked if this would provide sufficient benefit to warrant the price tab.

We asked Eisenman why this is now far more than originally planned and what’s included in the bill and here is what she shared:

“The original scope of work for Harcourt involved de-silting the watercourse. The revised scope of work is much more detailed, including the Gabion wall to stabilize the banks, re-contouring the banks to obtain a gentler slope, softening the 90 degree bend to the watercourse, installing a maintenance access trail, tree removal and associated landscaping, new headwalls, constructing a sediment pond and all the associated work and infrastructure with the diversion of stormwater from the west side of Brewster Road to the sediment pond. Also we will be adding a new extended walkway in front of the high school on Brewster. The space in Harcourt Woods is tight and the work is very labor intensive which also increases the cost.”

Residents also asked for trees to be planted to replace those that will be removed and Village managers said that landscape professionals, the Village arborist, and landscapers from Westchester County would be consulted.

At the close of the meeting, the committee passed a resolution to accept the modified proposal from Dvirka and Bartilucci and to put the design before the full Board of Trustees. They also asked the engineers for a more detailed plan and invited public comment.

(Pictured at top: Map of Harcourt Woods watercourse)