Scientific study finds fault with recent Chesapeake Bay model analysis

A new report by the Chesapeake Bay Program’s Scientific and Technical Advisory Committee (STAC) raises significant objections to a recent analysis comparing the Bay Program watershed model and a new USDA Natural Resources Conservation Service (NRCS) model of cultivated cropland in the Chesapeake Bay watershed.

In its analysis of pollution load estimates from cropland, LimnoTech recommended suspending implementation of the Chesapeake Bay TMDL – a “pollution diet” for the Bay and its tidal rivers – until the differences between the two models could be resolved.

STAC convened a panel of scientific experts to conduct an independent review of LimnoTech’s findings. The independent scientists found that LimnoTech’s comparison of the two models was scientifically flawed and did not provide sufficient evidence to suspend TMDL implementation.

According to the STAC panel’s report, the two models’ predictions are in approximate agreement when factual errors in LimnoTech’s analysis are corrected. More importantly, results from both models indicate that more management practices on cropland are needed to protect the Bay and its rivers.

The STAC reviewers encourage the Bay Program and the USDA to continue and expand sharing of data and modeling results. These cooperative efforts could help the Bay Program improve future versions of its model. STAC also suggests that future restoration efforts could be enhanced by the application of multiple models.

STAC is an independent advisory committee to the Chesapeake Bay Program. The committee convenes external, independent, scientific experts to review technical documents, policy methods and programs.

Visit STAC’s website to learn more about the scientific study.