NJ Clean Stream
njcleanstream.org
NJ’s water infrastructure was built for a climate that no longer exists
New Jersey’s water infrastructure was designed for a climate that is no longer the climate of New Jersey. The hydrological assumptions embedded in every reservoir, treatment plant, distribution main, and stormwater system — the frequency of extreme storms, the seasonal distribution of precipitation, the extent of coastal flooding, the temperature of source water — have all shifted. This is not a projection about the future. It is a description of what is already happening.
Four ways climate change is breaking NJ’s water system
Mechanism 1: Intense storms and extreme precipitation
A warmer atmosphere holds approximately 7 percent more moisture for each degree Celsius of warming. This produces more intense precipitation events when storms do occur — more moisture available to release in a shorter time. For New Jersey’s water infrastructure, this intensification has cascading consequences: stormwater systems designed for historical storm frequencies are increasingly overwhelmed; treatment plant intake capacity is stressed by high-turbidity, high-pollutant-load runoff arriving faster than systems can process; and combined sewers overflow during events that historically would not have triggered overflows.
Hurricane Ida, September 2021: The remnants of Ida produced record-breaking rainfall — more than six inches in several hours in some New Jersey locations. The result was widespread flash flooding, damage to water and wastewater infrastructure across the state, numerous combined sewer overflow events, and a graphic demonstration that “100-year flood” infrastructure is inadequate for a climate in which such events are becoming significantly more frequent.
Mechanism 2: Extended droughts and reduced water availability
While extreme precipitation events are increasing, so too are the dry periods between events. During drought conditions, multiple stresses compound: reservoir storage declines as evaporation exceeds inflow; stream flows at river intakes drop, reducing available supply and degrading water quality through reduced dilution, warmer temperatures, and higher concentrations of naturally occurring contaminants; and groundwater levels drop as aquifer recharge decreases while pumping continues.
New Jersey’s water allocation system was designed based on historical hydrological conditions. As climate change alters those conditions, allocation permits premised on historical water availability may be permitting withdrawals that exceed the sustainably available supply during drought years. The Delaware River Basin Commission — which manages water resources serving more than 15 million people in NJ, PA, DE, and NY — has been grappling with updating its allocation framework, but the process is slow and politically complex.
Mechanism 3: Sea level rise and saltwater intrusion
New Jersey’s coast has experienced some of the fastest rates of sea level rise on the Atlantic seaboard, driven by both global warming and regional land subsidence. Saltwater is advancing into freshwater aquifers in coastal South Jersey communities. Delaware River saltwater intrusion threatens drinking water intakes in Delaware and southern New Jersey during drought conditions when freshwater flows are reduced. This mechanism is examined in depth in Article 2 of this series.
Mechanism 4: Rising source water temperatures and water quality degradation
As air temperatures increase, the temperature of New Jersey’s rivers, reservoirs, and shallow groundwater increases with them. Warmer water supports more vigorous growth of algae and cyanobacteria — harmful algal blooms (HABs), which can produce toxins including microcystin, cylindrospermopsin, and anatoxin-a that are resistant to standard disinfection, are becoming more frequent and intense in New Jersey’s water supply reservoirs. Treatment plants not designed to manage HAB events are increasingly challenged by algal toxin contamination of their source water.
Warmer source water also affects disinfection chemistry. The reaction between chlorine and natural organic matter — which increases with warmer temperatures — produces higher concentrations of regulated disinfection byproducts (DBPs) including trihalomethanes and haloacetic acids. Treatment plants must balance adequate disinfection against DBP formation — a balance that becomes harder to maintain as source water warms.
The infrastructure resilience gap
New Jersey’s water infrastructure was not designed with any of these climate stresses in mind. Treatment plants were sited based on historical flood frequency maps that are now obsolete. Reservoir capacities were sized based on historical precipitation and evaporation data that no longer represent current conditions. Stormwater infrastructure was designed to hydraulic calculations that underestimate the intensity of current extreme events. The gap between what the existing infrastructure can withstand and what the climate now demands of it is the infrastructure resilience gap — and it is growing every year.
What climate adaptation for NJ water infrastructure requires
- Vulnerability assessment for every major water utility: Systematic assessment identifying which facilities are at risk from flooding, drought, saltwater intrusion, and rising temperatures, with prioritized investment plans to address the most critical vulnerabilities.
- Updated water allocation frameworks: NJ’s water allocation permits and drought management protocols should be updated to reflect current and projected future hydrological conditions using the best available climate science.
- Coastal protection for infrastructure: Treatment plants, pumping stations, and well fields in the coastal zone need flood barriers, elevated electrical equipment, backup power systems, and emergency interconnections proportional to sea level rise and storm surge projections for their specific locations.
- Source water diversification: Communities dependent on single, vulnerable sources should develop backup alternatives less exposed to specific climate risks — drought-resistant groundwater sources, utility interconnections, expanded reservoir storage, or water recycling capacity.
- Regulatory frameworks requiring climate risk disclosure: Water utilities should be required to disclose climate vulnerability assessments and adaptation plans to regulators and the public.
This is Article 1 of 3. Article 2 examines saltwater intrusion into South Jersey’s drinking water — which communities are most exposed and what adaptation looks like. Article 3 examines whether NJ’s water systems are prepared for the next major storm — and what genuine storm resilience requires.