Photo: nydiscovery7 (flickr)

The region’s disconnected water-supply systems face increasing risks from extreme weather conditions and climate change, as well as terrorism

In addition to sprawling development, pollution, and aging infrastructure, our water sources now face a new threat: climate change, which causes saltwater intrusion into aquifers, more extreme patterns of drought and heavy precipitation, and changing snowpack dynamics. They are also vulnerable to terrorist attacks. Yet coordinating policies and taking action is difficult. The systems that deliver our drinking water are based on political boundaries, unlike the aquifers from which they are sourced. A complex web of public water agencies, water districts, investor-owned utilities, and private wells is distributed across multiple layers of political jurisdictions.

On Long Island, for example, 2.6 million people rely on an overused sole-source aquifer that is vulnerable to contamination from septic systems, industry and stormwater runoff, and saltwater intrusion exacerbated by sea-level rise and the destruction of wetlands.

Overcome the physical and institutional barriers to protect and connect the region’s water-supply systems

The region’s freshwater supply is one of its most valuable resources. We must maintain its abundance and ensure its safety against the threats of contamination, overuse, climate change, and terrorism. We must protect its sources, manage its consumption wisely, and create a more connected network to ensure that even during an emergency, the tap does not run dry.

Protect the sources of the region’s drinking water from contamination and over-withdrawal

The region has made great strides in protecting the integrity of its water supply in recent decades. The 1993 Long Island Pine Barrens Protection Act in New York and the 2004 Highlands Water Protection and Planning Act in New Jersey preserved large areas where critical sources of drinking water were threatened by development. New York City, which has one of the most sophisticated water-supply systems in the country, is currently taking steps to preserve its level of redundancy through its Delaware Aqueduct Bypass project. There are still critical groundwater-recharging lands that remain unprotected, however, particularly places like Long Island, where aquifers are being pumped faster than they can recharge.

Contamination from both non-point-source and point-source pollution continues to threaten the region’s drinking-water supply. The most effective protections to the water supply include ending the discharge of raw sewage into our waterways and the cleanup of brownfields and Superfund sites. Changes made today would affect the drinking water a decade from now, as contaminants travel slowly through the ground.

Implement sound water-management practices

Compared with many other parts of the country, the New York Region faces fewer challenges from drought or overuse. Yet the magnitude of the effects climate change has on our water is unknown, and therefore sound water management is critical. To limit our vulnerability to less-predictable water supplies, we need more sophisticated drought monitoring and management, audits to determine the amount of water lost due to faulty infrastructure, aquifer storage and recharge (for both reserves, and to prevent saline intrusion), and encouraging the reuse of reclaimed water for certain purposes.

Connect the region’s water-supply systems

Even if the water supply is preserved and conserved in the ways described above, part of the region’s water supply could still fail for a number of reasons, potentially leaving millions of people temporarily without clean water. Connecting the region’s water-supply systems would create redundancy that would be lifesaving if drought, contamination, or saltwater intrusion were to interrupt the water supply to a part of the region. It would also allow repairs to existing infrastructure by temporarily sourcing water from another system. The U.S. Environmental Protection Agency classifies the connection of systems to diversify the water supply as a “no regrets” adaptation strategy, which means there are significant benefits regardless of the rate of climate change.

There are national and local precedents for connecting water supplies. Many interconnections already exist, though most are between smaller systems, and some have been inactive for decades, such as the several smaller systems in the Hudson Valley that maintain interconnections with New York City’s aqueducts. Since 2016, Newburgh’s interconnection to the Catskill aqueduct proved critical in mitigating a public health crisis when their main reservoir was contaminated from a toxic chemical spill at Stewart Air National Guard Base. A 1980-81 drought in New Jersey became so severe a temporary connection to New York City’s water supply was constructed across the George Washington Bridge—but never utilized and soon thereafter dismantled. The 2007 New Jersey Department of Environmental Protection Interconnection Study found utility interconnection opportunities not only improved water delivery during droughts and other emergencies, but also improved operations under normal conditions. New York City also explored the potential of an interconnection with neighboring water supplies in New Jersey across the Arthur Kill, and of reviving existing but antiquated connections with Nassau County to augment supply during construction of the Bypass Tunnel project under the Hudson, and subsequently to provide backup supplies for either party during an emergency.

These and past proposals to connect water-supply systems across jurisdictions have generally failed due to regulatory, political, and cultural challenges. Interconnection projects face a complicated maze of state and local regulation and utility contracts, ecological concerns, and different water treatment systems and standards. For example, the New York City-New Jersey interconnection would require approval or permits from at least 21 local, state, and federal agencies, and at least 17 for the proposed Queens-Nassau County interconnections.

Over the next decade, New York State Department of Environmental Conservation and Connecticut Department of Energy and Environmental Protection should identify opportunities for water-supply interconnection, similar to the 2007 NJDEP study. States should implement regional water-management plans, while states and land trusts could partner to identify land-acquisition priorities that conserve the region’s drinking water supply.


By 2040, the completion of bidirectional interties between the region’s major water systems—for example, between Long Island and New York City, and New York City and Northern New Jersey—would ensure all parts of the region have access to clean water in the event one system is under stress, thereby reducing risks to public health.

Paying for it

Water infrastructure funding typically comes from rate payers, federal or state grants or loans, or tax-exempt municipal bonds, while utilities themselves (whether public or private) implement the projects. Utilities may be able to generate revenue through interconnection agreements by negotiating fees with the purchasing utility.

It is difficult to estimate costs for all the strategies mentioned. A similar, single water-supply interconnection project in California cost between $5 million and $10.5 million, though even the cost of that type of project could vary greatly depending on various factors such as distance and whether additional facilities are required.