For 305(b)/303(d) water quality assessments, NHDES uses assessment units to cover the Great Bay Estuary that are coincident
with the shellfish growing areas established by the NHDES Shellfish Program. Great Bay itself consists of seven different
assessment units. Nitrogen and eutrophication parameters are logically evaluated utilizing data from larger aggregates of
assessment units covering contiguous areas. Eutrophication effects are less localized than the bacteria pollution sources
that affect shellfish harvesting. Therefore, NHDES aggregated the assessment units in the Great Bay Estuary into 27
assessment zones. The assessment zones were developed in cooperation with the PREP Technical Advisory Committee. For the
Salmon Falls/Piscataqua River, the assessment zones cover both the New Hampshire and Maine sides of the main stem of the
river. The river is well mixed and data from both sides of the state line are needed to provide a comprehensive dataset
for assessments. However, the assessment determinations made by NHDES only apply to the New Hampshire side of the river.
The Maine Department of Environmental Protection makes its own assessment determinations for the Maine side of the Salmon Falls/Piscataqua River.
Great Bay Estuary assessment zones used to evaluate nitrogen and eutrophication parameters for 305(b)/303(d) assessments purposes.
These zones are also used by the Piscataqua Region Estuaries Partnership (PREP) for reporting eelgrass cover in their State of
Our Estuaries reports.
Currentness_Reference: Publication Date
Place_Keyword_Thesaurus: ISO 19115 Topic Category
Place_Keyword: New England
Place_Keyword: New Hampshire
Place_Keyword: Great Bay
This data set is to be used as a primary reference source. This is public information and may be interpreted by organizations,
agencies, units of government, or others based on needs; however, they are responsible for the appropriate application.
Federal, state, or local regulatory bodies are not to reassign to the New Hampshire Department of Environmental Services
any authority for the decisions they make. Photographic or digital enlargement of these maps to scales greater than that
at which they were originally delineated can cause misrepresentation of the data. If enlarged, the maps will not include
the fine detail that would be appropriate for mapping at the small scale. Digital data files are periodically updated,
and users are responsible for obtaining the latest version of the data
Contact_Person: Matt Wood
Contact_Organization: New Hampshire Department of Environmental Services