Major Watersheds (Water Quality Rating)

Major Watershed boundaries of Martha's Vineyard. These boundaries were created by the MVC and the SMAST Mass Estuaries Program. A computer model paired with local data were combined to delineate these coastal pond watershed boundaries. The finalized Mass Estuaries Reports for each pond can be found here. Please visit the SMAST website for an overview of the Estuaries Program. The Water Quality Rating is based on the amount of Nitrogen in the pond and the pond's Nitrogen Loading Limit. Visit the MVC's website for more details about each pond. Minor Update 9/26/2023: Menemsha Pond Watershed quality rating changed from Good to Compromised this is due to, specifically, Stonewall Pond and Nashaquitsa Pond quality being compromised while the main Menemsha Pond is OK. Another change to note is that the latest MVC Water Quality Policy of 2023 has condensed the water quality categories to 2 options: 'Good' or 'Impaired'. While this dataset still utilizes the 'compromised' category (which is a middle ground between Good to Impaired, when viewing this dataset thru the lens of the Water Quality Policy the 'compromised' category should be combined with the 'impaired' category.