In the list of Atlantic Yards promises broken, the newly-revealed loss
of a green roof (3+ acres) on the arena follows 1) the decision to make
publicly-accessible open space on the arena private
and 2) the decision to move the project's flagship tower (then called "Miss
Brooklyn"), promised to not
block views of the Williamsburgh Savings Bank's clock tower, so it would
block such views, even with a reduction in height.
The difference might be that the green roof was relied on significantly in the Empire State Development Corporation's environmental review because it would help with stormwater management and thus help prevent against CSOs (combined sewer overflows).
Does its loss invalidate the Final Environmental Impact Statement (EIS), which has been challenged in state court? Unclear. The case was dismissed and is now on appeal, with arguments to be heard in September.
From the FEIS chapter on Infrastructure:
Includes detention tanks in Arena block and LIRR, seasonal retention in Arena block, and Arena green roof.
From the chapter on Landscape Design: The proposed publicly accessible open space and the arena’s green roof would absorb some of the rainwater runoff that would otherwise flow directly into the City’s water drainage system.
From the chapter on Open Space:
In addition, approximately one acre of private open space intended for use by the project site tenants would be built on a portion of the roof of the proposed arena.... This green space would be designed with detention and retention basins to limit the amount of runoff that flows directly into the City’s water drainage system (see Chapter 11, “Infrastructure,” for discussion of green design features).
From the Appendix
Here are some excerpts from the report submitted by FCR's consultants, Hydroqual:
The Atlantic Yards plan employs a variety of technologies and stormwater management strategies to meet the FCR goal of not affecting water quality in the Gowanus Canal or East River as compared to the project no-build condition in the planning years 2010 and 2016. These include:
• On-site detention and retention tanks for stormwater with multi-level discharge points to optimize storage
• Use of green roof on the arena to intercept portions of runoff from reaching the sewer system during rain events.
FCR retained several consultants to address different aspects of the design related to wastewater and stormwater:
• Judith Nitsch Engineering (JNE) provided engineering and architectural services regarding site design and stormwater management strategies for the project site.... In addition to detention/retention of stormwater, the use of green roofs on the arena as an additional stormwater management feature was evaluated by JNE using computational methods that are applicable at the site level.