The Watershed Institute has released its 2026 Clean Water Report Card, finding broad but generally modest declines in water quality across central New Jersey. The report identifies pH, turbidity, and chloride as the parameters showing the most widespread deterioration, while also highlighting practical actions residents, municipalities, and state leaders can take to help reverse the trend.
The annual Clean Water Report Card assesses the health of local streams and lakes across 26 municipalities, using data collected by trained StreamWatch volunteer scientists at 114 monitoring sites. The 2026 report reflects monitoring conducted from January 2021 through December 2025.
Each parameter—temperature, turbidity, pH, dissolved oxygen, nitrate, phosphate, chloride, macroinvertebrates, and E. coli—is scored at the site level on a four-point scale of Excellent, Good, Fair, or Poor, using New Jersey Department of Environmental Protection parameter-specific water-quality standards. Results are then aggregated to provide subwatershed- and municipal-level scores.
“The Clean Water Report Card gives communities a clear picture of the condition of the waterways that run through their neighborhoods,” said Jim Waltman, Executive Director of The Watershed Institute. “While many of the changes are modest, the widespread declines in pH, turbidity, and chloride are a warning that regional pressures—from stormwater runoff and erosion to winter road-salt use—are affecting water quality across central New Jersey.”
Broad Declines, With Several Notable Drops
Compared with the previous report card, which covered data collected from 2020 through 2024, water-quality scores declined more often than they improved.
- Twenty-two of 31 subwatersheds recorded a decrease in combined water-quality scores.
- Twenty of 26 municipalities recorded a decrease in combined scores.
- Most changes were modest, but several locations experienced a full-category decline.
- Five subwatersheds—Bear Brook, Beden Brook, Fiddlers Creek, Heathcote Brook, and Little Shabakunk Creek—dropped a full overall scoring category.
- Millstone Township and Trenton City also dropped a full overall category.
- Cranbury Brook and East Windsor Township posted the strongest gains of the reporting cycle.
- Temperature scores improved in several municipalities, including Trenton City, Lawrence Township, and Princeton.
- The report found that pH declined more broadly than any other monitored parameter. Eleven of 31 subwatersheds and eight of 26 municipalities dropped at least one pH scoring category, with several falling into the Poor range.
Chloride—closely associated with winter road-salt application—also worsened consistently. Six subwatersheds and nine municipalities dropped a chloride scoring category, while none improved.
Turbidity, which measures cloudiness in water and can reflect sediment runoff and streambank erosion, also declined broadly across the region. Dissolved oxygen, nitrate, and E. coli showed notable declines in some places, though these changes were more localized rather than regional. Temperature, macroinvertebrate, and phosphate scores remained largely stable.
Why Water Quality Matters
Healthy streams and lakes reflect the condition of the lands, roads, infrastructure, and communities that surround them. Changes in pH and turbidity can stress fish and aquatic insects, diminish biodiversity, and affect the broader ecological health of waterways.
Lower pH can also increase the solubility of naturally occurring toxic metals and nutrients in sediment, raising the likelihood that they become harmful or bioavailable to aquatic life. Elevated chloride concentrations from road salt are especially concerning because chloride can persist in waterways for years, and most water-treatment processes do not remove it.
The report’s regional pattern suggests shared pressures rather than one isolated pollution event. Likely contributors include polluted stormwater runoff, streambank erosion, and winter road-salt use. These challenges are compounded by increasingly frequent short-duration, high-volume precipitation events in New Jersey, which can wash sediment, nutrients, salt, and other pollutants into local streams and lakes.
Actions Residents and Leaders Can Take
The Watershed Institute is calling on residents, municipal officials, and state leaders to work together to protect and restore central New Jersey’s waterways.
Residents can:
- Reduce fertilizer use to limit nutrient runoff into nearby waterways.
- Plant native species, which help filter stormwater and capture pollutants before they reach streams.
- Maintain a vegetated buffer along streambanks rather than mowing to the water’s edge.
- Learn more about river-friendly practices at The Watershed Institute’s River-Friendly program.
Municipal leaders and staff can:
- Adopt strong stormwater mitigation ordinance and stream buffer protection ordinances patterned after The Watershed Institute’s model ordinances.
- Adopt and implement best practices for road-salt application.
- Store road salt properly to prevent it from entering groundwater and nearby waterways.
- Explore guidance through The Watershed Institute’s road-salt resources.
State leaders can:
- Ensure implementation of New Jersey’s Resilient Environments and Landscapes rule so redevelopment projects include stormwater-management measures that reduce polluted runoff.
- Support stronger protections for local waterways by visiting The Watershed Institute’s action page.
About StreamWatch
Since 1992, The Watershed Institute’s StreamWatch program has engaged community members in protecting water quality and habitat throughout central New Jersey. Today, more than 100 trained volunteers monitor roughly 60 streams and lakes through three specialized teams:
- The Chemical Action Team (CAT) collects monthly chemical and nutrient measurements.
- The Biological Action Team (BAT) conducts annual habitat assessments and macroinvertebrate sampling.
- The Bacterial Action Team (BACT) monitors E. coli and harmful algal blooms throughout the summer.
StreamWatch data are shared with municipal and state leaders, including the New Jersey Department of Environmental Protection, to help inform regulatory actions that protect and restore waterways under the Clean Water Act.
Read the executive summary of the report here
About The Watershed Institute
The Watershed Institute is a nonprofit organization dedicated to protecting and restoring water and the natural environment through conservation, advocacy, science, and education. Through programs such as StreamWatch, the organization works with residents, schools, municipalities, and policymakers to safeguard central New Jersey’s streams, lakes, and drinking-water resources.
Media Contact:
Donna Gregory
