With public review underway on the controversial land use application, plan opponents tapped a team of climate experts to poke holes in the city’s environmental assurances during a virtual meeting Tuesday. The city has pushed back on their claims, calling them an attempt to undermine an environmentally conscious development framework.

Rising sea levels could trigger toxin-laced flooding and frequent waves of human waste, dubbed “poonamis,” near the Gowanus Canal, according to scientists critical of the city’s plan to rezone 82 blocks around the filthy Brooklyn waterway.

With the public review process underway on the controversial Gowanus land use application, plan opponents tapped a team of climate experts to poke holes in the city’s environmental assurances during a virtual meeting Tuesday. The city’s Department of City Planning (DCP) has pushed back on their claims, calling them an attempt to undermine an environmentally conscious development framework.

The climate crisis argument is one of several fronts in local advocates’ fight against the rezoning.

“Sea level rise increases flood risk significantly,” said climate consultant Adrian Santiago Tate, CEO of climate consulting firm High Tide.*  “How many storms like Sandy can we expect over the coming decades?”

The city’s proposal, known as the Gowanus Neighborhood Plan, would enable construction of 8,500 new apartments within a large swath of the neighborhood — from Bond Street to the west, 4th Avenue to the east, Baltic Street to the north and Huntington, 3rd, 7th and 15th streets to the south. City officials say the plan would create about 3,000 affordable apartments, including a 950-unit complex on the city-owned property Public Place, the site of a former gas plant that seeped coal tar toxins deep into the soil.

Santiago Tate presented a map depicting the confines of the proposed rezoning and the overlapping extent of flooding from Superstorm Sandy. He played an infamous 2010 YouTube video of excrement surging along the channel after overflowing from the sewer. New residents will only add to the burden on the sewage system, plan opponents say.

“More extreme rainfall,” fueled by climate change will also lead to frequent floods that cover larger swaths of land and disperse contaminants further afield, added coastal flooding expert D.J. Rasmussen. Rasmussen questioned the city’s plan to increase the population in a flood-prone region with a disastrous environmental record, particularly on the Public Place site, and said planned remediation and flood mitigation efforts may not work.

Higher walls along the canal and flood protections mandated under New York City buildings code could have the unintended consequence of redirecting overflow into new areas, he said.

“The water has to go somewhere,” Rasmussen said. “It’s quite chaotic and really impossible to know without additional modeling.”

He also cautioned that large-scale barriers, like a seawall or a storm surge gate at the entrance to the canal, may never leave the drawing board.

Rezoning opponents from the group Voice of Gowanus, which organized Tuesday’s event, say the city’s Environmental Impact Statement does not pass legal muster without independent study from the Environmental Protection Agency, Federal Emergency Management Administration or the Army Corps of Engineers. New York City has a conflict of interest, said Voice of Gowanus organizer Jack Riccobono, because it has slow-walked federal cleanup orders even as faulty sewer design contributes to hundreds of millions of gallons of raw sewage rushing into the canal each year.

“The city is on the one hand pushing this massive rezoning to bring in all this development, but on the other hand have not been compliant in addressing the decades of environmental abuse going on in our communities,” Riccobono said.

Supporters of the rezoning plan, however, say the intensive remediation efforts will make the region safer, while enabling more low- and middle-income New Yorkers to move into the neighborhood. The bulk of the rezoned area is located in Brooklyn Community District 6, where nearly two-thirds of the population is white and 9.6 percent of residents live below the New York City poverty line — half the Brooklyn average, according to city data.

The land use plan is backed by several housing advocates, Mayor Bill de Blasio and local Councilmember Brad Lander, whose vote is likely essential for passage by the full City Council. City lawmakers typically vote in lockstep with the local member on Universal Land Use Review Procedure (ULURP) applications, a custom known as “member deference.”

Lander and other supporters say that, unlike other rezonings, the Gowanus plan will allow more working class New Yorkers to move into the predominantly white and relatively wealthy community. Opponents like Voice of Gowanus refute that characterization of the neighborhood, and point out that the bulk of affordable housing will be located at the most polluted site location, at Public Place.

In a statement Wednesday, DCP spokesperson Joe Marvilli criticized the environmental warnings put forth by the Voice of Gowanus and its climate scientist allies.

“These claims are just the latest attempt to preserve a status quo that keeps out low- and middle-income New Yorkers and exacerbates displacement,” Marvilli said. “Through our plan, new mixed-income housing development would lead to remediated brownfields, solar and green roofs, more stormwater capture, reduced combined sewer overflows into the Canal and a more resilient shoreline.”

The city consulted with various environmental experts, community groups and federal agencies go develop the Gowanus plan, Marvilli said.

“We look forward to continuing public review and a brighter, more affordable and more resilient Gowanus,” he added.

The next phase of the land use review process for the rezoning proposal will take place June 3, when Community Boards 2 and 6 will hold a joint outdoor public hearing in coordination with the city, the result of an order from a Brooklyn judge. The event will take place at 3:30 p.m. in J.J. Byrne Park.

Voice of Gowanus sued the city in January over its virtual ULURP plan, charging that land use rules require in-person hearings to ensure all residents, including those without internet access, can weigh in.

Judge Katherine Levine ruled that the city had to hold an in-person hearing and said no more than 200 people can attend under current COVID-19 gathering rules. Other participants will tune in through Zoom. Levine temporarily stopped the ULURP clock on the rezoning until approving the city’s public hearing plan Wednesday.

“We will work to make sure the public can fully participate and make their voices heard on this important proposal to advance affordability, equity and opportunity in Gowanus,” Marvilli said.

The Gowanus lawsuit inspired opponents of another rezoning, across the East River in wealthy SoHo, to file a similar complaint that accused the de Blasio administration of exploiting the pandemic to circumvent in-person, and often contentious, land use hearings. The city is proposing to rezone the Manhattan neighborhood to allow for an estimated 3,200 new housing units to be built, which could include between 600 to 900 affordable apartments.

A Manhattan judge on May 3 denied their request for an order pausing ULURP on the SoHo proposal, but the City Planning Commission postponed a vote to certify the land use application.

The planning commission next meets May 17. Marvilli says the city will introduce the SoHo application soon but did not provide a specific date.

“We are finalizing a few small matters related to the application, and look forward to beginning public review in the near future,” he said.

*Editor’s note: an earlier version of this story originally identified Adrian Santiago Tate by an outdated title. The reference has been updated.