New York Construction News staff writer
The New York City Department of Environmental Protection (DEP) marked the one-year anniversary of Hurricane Ida by announcing stormwater infrastructure initiatives aimed at making the city more resilient to extreme rainfall.
“One year ago, Hurricane Ida brought the heaviest rainfall in our recorded history and flooded our streets, subways, and basements, and, worse, claimed the lives of 13 of our neighbors,” said Mayor Eric Adams.
“We are taking action to protect our city and prevent future tragedies, by ramping up flood protection with sewer advancements and curbside rain gardens, as well as by building out our cloudburst infrastructure and expanding other flood mitigation options, including the bluebelt drainage system.”
In the weeks after the remnants of Hurricane Ida flooded many parts of the five boroughs, the city accelerated funding for programs to manage extreme rainfall, including:
- $2.1 billion in new capital funding to build sewers and green infrastructure;
- $238 million of capital funds accelerated for sewers and green infrastructure; and
- $400 million in new capital funding advanced for the New York City Department of Transportation (DOT), New York City Department of Education, and NYC Parks, as well as NYCHA for green infrastructure and other stormwater management initiatives. These projects are ongoing.
DEP is working with the DDC to upgrade and build out the sewer system to modern standards. In Southeast Queens, the city is investing $2.5 billion to install upgraded sewers. DDC is working in Gowanus, Brooklyn to complete a $39 million storm sewer project that will lead to cleaner water in the canal and reduce flooding in that area. Completion is scheduled for November 2022.
“The Department of Design and Construction is proud to be part of a multi-agency effort addressing the wide-ranging impacts of climate change, including events like Hurricane Ida,” said Commissioner Thomas Foley. “We are building new sewers in parts of the city that didn’t have them, increasing capacity to handle heavier rainfall events in others, rolling out innovative efforts to divert stormwater away from our sewer system, and installing thousands of green infrastructure projects across the five boroughs.
“Our work is not done, and we are finding ways to actually accelerate delivery so we can bring these projects online even faster in the future.”
In Woodside, Maspeth, Middle Village, and Glendale in central Queens, the city has completed several projects to eliminate chronic flooding. The city is currently using advanced micro-tunneling technology to double the size of sewers and reduce or eliminate flooding. This $119 million project is expected to be completed in 2023.
The city also completed a $47 million project to raise streets and add almost half a mile of new storm sewers to reduce flooding in Broad Channel, Queens — an area frequently inundated by Jamaica Bay during high tides and storms. Phase Two — an $83 million project that will add an additional 3,200 linear feet of new storm sewer on previously unsewered blocks — is anticipated to be completed in 2024.
To alleviate flooding in South Beach, Staten Island, the city completed a $98 million project that encompasses 61 individual blocks and includes the reconstruction of over three miles of storm sewers, ranging from 12 inches in diameter up to rectangular sewers that are 8.5 feet wide by four feet high. The work included the installation of 200 new catch basins to better capture stormwater and direct it to new storm sewers.
In Brooklyn, the city completed a $166 million project that included the construction of 6.5 miles of new sewers. Building new sewers and separating previously combined sewers creates additional capacity in the drainage system to reduce flooding and cut sewer overflows into Fresh Creek by 189 million gallons annually.
“Hurricane Ida showed us that we must continue to invest in stormwater mitigation and capture, and I’m proud that this administration is taking action to advance this much-needed work,” said Parks and Recreation Commissioner Sue Donoghue.
While catch basins and sewers will continue to serve as the backbone of the drainage system, in many places, sewers cannot be built any larger than they are. To manage increasing volumes of stormwater, new drainage and absorption tools must be added to increase protection and resilience.
Also, NYC is funding curbside rain gardens with more than 11,000 installations already constructed, and construction set to begin on 1,000 more by the end of this year. The 2,300 newly constructed rain gardens, each with a capacity to absorb up to 2,500 gallons of water during a storm.
As part of an ongoing pilot program, more than three miles of porous pavement have been installed within roadways in Queens and the Bronx. Porous pavement manages more stormwater runoff than typical curbside rain gardens and is easier to site. Engineers are currently designing more than 56 additional miles of porous pavement for Brooklyn and the Bronx.