November 1, 2016
By Neal Tepel
New York , NY – A new $250 million water tunnel connecting Brooklyn to Staten Island has been activated. This will ensure the borough has a safe, reliable drinking water supply in the aftermath of a disaster.
The new, deeper tunnel – called a siphon – is a critical back-up that can deliver up to 150 million gallons of safe, clean drinking water per day to Staten Island from Brooklyn under the New York Harbor. Hurricane Sandy’s storm surge damaged the project and tunnel in 2012. During an 18-month shutdown for repairs, resiliency measures were put in place to prevent future storm damage.
“Our city is better prepared to tackle 21st century threats like Sandy today than ever before. This water tunnel is one measure that will help Staten Island spring back to action in the event of a disaster that would disrupt the water supply,” said Mayor Bill de Blasio. “Measures like these are being implemented across the City, from Red Hook to the Rockaways, our City is becoming Safer and more resilient every day.”
The rebuilt water tunnel prepares the big apple for future storms. Plans for the upgraded water system were redrawn after Sandy to raise permanent infrastructure, including the chlorination station, above the new 100-year flood plain. The project was funded jointly by DEP and the Port Authority of New York and New Jersey.
All of New York City’s high-quality drinking water is collected in protected reservoirs located up to 125 miles north of the city. From there it travels south through aqueducts to Hillview Reservoir in Yonkers where it enters City Water Tunnels Nos. 1, 2 and 3. These tunnels are located roughly 500 feet beneath street level and travel through the boroughs of the Bronx, Manhattan, Queens and Brooklyn. Two siphons were built in the bed of New York Harbor to connect Staten Island to Brooklyn, and the City’s upstate water supply, in 1917 and 1925 respectively. As Staten Island’s population and its demand for water grew, in 1970 the 10-foot diameter Richmond Tunnel was built deep in the bedrock beneath New York harbor and became the primary water conduit to the Island. The original siphons have since been kept in service as a back-up connection to ensure a reliable supply of drinking water for the nearly 500,000 residents on Staten Island who consume approximately 50 million gallons of water each day.
The new 72-inch siphon was excavated at a depth of 100 feet and replaces the two existing water connections that run from Bay Ridge in Brooklyn to Stapleton and Tompkinsville on Staten Island. These two connections were removed during the Port Authority’s harbor deepening project. The new siphon, which successfully completed pressurization and water quality testing earlier this fall, serves as the back-up water feed for Staten Island. If needed, it has the capacity to carry up to 150 million gallons per day.
Work on the project began in August 2011 and included the construction of access shafts in Brooklyn and Staten Island. A 300 foot-long, 110 ton Tunnel Boring Machine (TBM) was lowered into the Staten Island shaft in July 2012 and had progressed approximately 1,600 feet towards Brooklyn when operations were suspended on the evening of October 28, 2012 in advance of the approaching Hurricane Sandy. The historic storm surge associated with Sandy flooded the Staten Island shaft and the excavated tunnel with sea water and severely damaged the TBM. After the tunnel and shafts were dewatered and damage assessments were completed, months of repairs and testing of the TBM followed. On April 14, 2014, the TBM resumed work and excavation of the tunnel was completed in February 2015.
“This monumental project 100 feet below the harbor is a significant investment in the future of our borough, ensuring a reliable supply of drinking water for all Staten Islanders should it be needed. As we remember the devastation that Hurricane Sandy brought to our shores four years ago, completion of this tunnel is reminder of the meaningful investments we are making to ensure our safety and resiliency in the future. I thank the Mayor, the Department of Environmental Protection, the NYC Economic Development Corporation and the Port Authority for ensuring the completion of this project,” said Council Member Deborah Rose.