Chilmark Pond

Chilmark State of the Pond Reports: 

     Year 2020 

     Year 2019 


The 3,500-acre watershed is completely in Chilmark.


The pond has an area of 146 to 242 acres, a mean depth of 2.1 feet, and a tidal range of 0.5 feet.

Water Quality

The MVC categorized this pond as Impaired. Historically eelgrass is not known to be in the pond. The pond has a high nitrogen load, very low transparency, and few oysters.


Up-Island 208 Project

The 208 Equivalency Report (aka Up-Island Management plan) is a comprehensive review of water quality and habitat conditions in five Up-Island watersheds. The information presented in the report is intended to provide criteria to Up-Island communities as they establish baseline assessment of existing conditions and finalize their nitrogen mitigation plans.

Massachusetts Estuaries Project Study

 The MEP report (below) found that the pond is impaired, but that a 15% reduction in controllable nitrogen loading in the pond or a 32% reduction in nitrogen in wastewater would solve the problem. They thought the objective could be achieved by increasing the number and length of breaches to the pond each year. Also, since the density is low, the use of Innovative Alternative wastewater treatment systems could be enough to lower the nitrogen levels from wastewater to acceptable levels. 


  • Regular pond openings and aquaculture projects help to improve water quality.
  • A “Floating Islands” pilot project has been installed in an attempt to increase microbial denitrification and to act as an artifical wetland.

Pond Association

Office location:

Office location:

The Stone Building
33 New York Avenue
Oak Bluffs, MA 02557

Telephone: 508-693-3453
Fax: 508-693-7894

Mailing Address

Mailing address:

Martha's Vineyard Commission
P.O. Box 1447
Oak Bluffs, MA 02557

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