Chesapeake Bay score rises to record 56%, but regions diverge

The University of Maryland Center for Environmental Science (UMCES) released its 2026 Chesapeake Bay and Watershed Report Card on October 13, 2026. UMCES’s Integration and Application Network produced it. The Bay scored 56% (C+), its highest score in the report card’s tracking record and six percentage points above the 50% (C) recorded in 2025.

The report summarizes data collected through December 2025. It found improving health trends in eight of the Bay’s 15 regions, compared with six in the previous report. The higher Bay-wide score and larger count of regions with improving trends coexist with substantial differences among areas.

Regional grades and water-quality trends vary

The Lower Bay received a B+, while the Lower Western Shore received a D-. The Chesapeake Bay Foundation also identified D grades for Maryland’s Patapsco and Back rivers, the Lower Western Shore and the Patuxent River. Those are the foundation’s characterizations of the regional results. They show why the overall Bay grade should not be read as a uniform account of conditions across all parts of the watershed.

The 2026 report included watershed-wide water-quality trends for the first time. UMCES reported that water quality was improving overall, but that trends declined in the Lower Eastern Shore and Lower James regions. These water-quality trends are distinct from the count of regions with improving overall health trends and from the regional letter grades; they describe different parts of the assessment.

The watershed score measures a separate set of indicators

The report also assigned the Chesapeake Bay watershed a score of 56% (C+). That is a separate assessment, not a second score for the Bay’s ecological condition. It combines 12 indicators: five ecological, four economic and three societal. The matching percentages therefore do not mean that the two assessments measure the same things.

UMCES’s Heath Kelsey said the combination of improving watershed water quality and improving scores for the tidal Bay was strong evidence that restoration efforts were working. Chesapeake Bay Foundation President and CEO Hilary Harp Falk said favorable weather conditions also contributed to the latest results. The overall score does not quantify the separate contribution of restoration, weather or other factors.

The report’s findings describe conditions assessed using data through December 2025. The score and trends therefore reflect that reporting period, rather than conditions after the cutoff.