The Chesapeake Bay earned a C+ on its annual report card Oct. 13. That is the highest grade in the 40 years the bay has been tracked. But the Patuxent River, which borders all three Southern Maryland counties, still scored a D.
The University of Maryland Center for Environmental Science released its 20th annual Chesapeake Bay and Watershed Report Card, covering data through December 2025. The bay as a whole scored C+. So did the larger watershed, which UMCES grades on ecology, society and economy.
The Patuxent’s D comes from the Chesapeake Bay Foundation, which issued a statement the same day. CBF said the Patapsco and Back rivers near Baltimore and the Lower Western Shore also scored D’s. UMCES said the Lower Western Shore’s D- was the lowest of the 15 regions it grades.
“Rivers like the Patapsco, Patuxent, and Choptank continue to be overburdened by pollution, which is driven by increased development, more intense rainfall, and climate change,” said Allison Colden, CBF’s Maryland executive director. “Our collective efforts to improve the health of the Bay are working, but the job is not done. We’re still lacking uniform progress across Maryland’s tributaries.”
What improved
UMCES said long-term trends keep getting better for most regions and measures. Eight of the 15 regions had improving trends: the Rappahannock, James, Elizabeth, Patapsco and Back rivers, the Upper Western Shore, Lower Eastern Shore, Upper Bay and Lower Bay. Virginia’s Lower Bay scored a B+, the best score on record for any region.
For the first time, the report card included watershed-wide water quality trends. They are improving overall, UMCES said. The water quality index tracks nitrogen, phosphorus, water clarity and conductivity. Underwater grasses are up, and nitrogen and phosphorus pollution is down, according to CBF.
“Real recovery isn’t measured in single years — it’s built over decades,” said Fernando Miralles-Wilhelm, Ph.D., UMCES president. “This milestone isn’t the finish line or a reason to pause; it’s momentum.”
Heath Kelsey, Ph.D., who directs UMCES’s Integration and Application Network, called the results “strong evidence that restoration efforts are working. We have a long way to go, but we are headed in the right direction.”
What is getting worse
CBF pointed to measures moving the wrong way. Waters overall are getting cloudier. Chlorophyll a, the measure used for harmful algal blooms, is trending worse. Water quality is declining in two regions: Maryland’s Lower Eastern Shore and Virginia’s lower James River.
The weather also helped. “Favorable weather conditions also contributed to the latest results,” said Hilary Harp Falk, CBF’s president and CEO. “But a C+ is not a final grade. Too many local rivers and streams continue to struggle, and too many communities face threats from pollution, flooding, and a changing climate.”
In Virginia, the York and Elizabeth rivers scored D’s. Pennsylvania’s Lower Susquehanna watershed scored a D+ and is not improving.
What comes next
The report card is a yardstick for the revised Chesapeake Bay Watershed Agreement, which sets pollution-reduction and restoration goals with a 2040 deadline. Colden urged state leaders “to maintain support for the programs and funding that keeps Bay health trending in the right direction.”
Calvert waterfront owners are already living with the rules side of that effort. A state law that took effect Oct. 1 makes Critical Area variances harder to get.
Region-by-region scores are on UMCES’s report card website.
