OVERVIEW

This datalayer delineates those watershed areas in which most waters are afforded Outstanding Resource Waters classification under the Massachusetts Surface Water Quality Standards of 2007. According to 314 CMR 4.00: "Certain waters shall be designated for protection under this provision in 314 CMR 4.06(3) including Public Water Supplies (314 CMR 4.06(1)(d)1.). These waters constitute an outstanding resource as determined by their outstanding socioeconomic, recreational, ecological and/or aesthetic values. The quality of these waters shall be protected and maintained". NHESP Certified Vernal Pools are designated as Class B Outstanding Resource Waters but are NOT included in this datalayer, see Section 4.06(2) in 314 CMR 4.00. In ArcSDE the layer is ORW_POLY. For more information see: http://www.mass.gov/dep/service/regulations/314cmr04.pdf.

The original source materials for this datalayer correspond to the MassGIS Surface Water Supply Watersheds and Areas of Critical Environmental Concern (ACEC) datalayers. Additional watershed information was created by using USGS elevation data and ESRI ArcHydro Tools to delineate watersheds. Additional information for the North and South Rivers was derived by buffering the DEP Wetlands that were selected to match the enabling legislation. The Elizabeth Islands shoreline was also derived from the DEP Wetlands datalayer and buffered 1000 feet. Rhode Island public water supply sources was taken from the Surface Water Supply Watersheds datalayer and clipped to match the regulatory area definition.

Surface Water Supply Watersheds and Areas of Critical Environmental Concern (ACEC) features were extracted and compared against the Massachusetts Surface Water Quality Standards of 2007 to determine which features were designated as containing Outstanding Resource Waters (ORW). Relevant areas within ACEC’s were extracted in accordance with the limits cited in the water quality standards as revised in 2007. Additional areas added included drainage basins of protected scenic rivers, protected wetlands areas and areas that contribute to other states surface water supplies. This information was extracted from the component datalayers and appended into a single ORW datalayer. Some abandoned public water supplies exist in this layer because they are still listed in 314 CMR 4.00, these watersheds were derived from the USGS Sub Basins datalayer. Since the input data contains overlapping features, there may be multiple orw’s at the same location. The data was not dissolved except to create multipart polygons of the same feature. Please refer to the underlying data’s documentation to see how it was created and is attributed.

While the primary designation of ORWs is through the Massachusetts Surface Water Quality Standards at 314 CMR 4.00, the further definition and protection of specific resources is addressed by and through the application of regulations promulgated pursuant to the Massachusetts Clean Waters Act, the federal Clean Water Act, Massachusetts drinking water protection laws, the federal Safe Drinking Water Act, and possibly local bylaws or ordinances. This datalayer only serves to highlight areas where ORW issues should be more specifically addressed by the relevant state and federal statutes and regulations or other local legal requirements. The scale and source materials for some features in this datalayer are far coarser then that at which most specifically regulated activities and resource issues should be examined. Specifically, watershed delineations, even when using digital elevation data are a remote interpretation of the ground surface, and not all drainage features may be mapped, contributing to spatial accuracy errors and, in some locations, may require professional judgment. Please consult the contributing datalayer documentation for specific accuracy information and data collection methods.

The ORW field was retained for compatibility with the previous dataset, however code 3 was removed because the features were not dissolved for code 1 and 2. Attributes were added for the Major Basin the orw is in, areas in acres and square miles, attributes for source id and type were taken from the Surface Water Supply Watersheds datalayer and an attribute for ORW type was added. The datalayer ORW_ARC has been discontinued. Some of the features are discontinous but are represented by multipart polygons, areas given are for the entire feature.

The attributes for each feature are:
 

Field Name		Description
ORW_TYPE		Type of ORW:  - ACEC  - Cape Cod NS  - Protected Shoreline  - Public Water Supply (Watershed, Retired and RI)  - Scenic/Protected River  - Wildlife Refuge
ORW_NAME		Name of the ORW: SITENAME from Surface Water Supply Watersheds, NAME from Areas of Critical Environmental Concern, or from 314 MMR 4.00 list
MAJ_BASIN		Major basin name, from Major Drainage Basins
PWS_SOURCE_ID		Surface water supply SOURCE_ID from the Surface Water Supply Watersheds datalayer, ex 3030001-01S
PWS_TYPE		Surface water supply TYPE from the Surface Water Supply Watersheds datalayer:  - SW=Active  - ESW=Emergency  - RI=Rhode Island Source
AREA_ACRES		Area of the feature in acres
AREA_SQMI		Area of the feature in square miles
ORW		- 1 – Surface Water Supply Watershed  - 2 – Other (retained for compatibility with archived layer, see above)

EDITING

The Massachusetts Department of Environmental Protection (DEP) GIS Program is maintaining this datalayer. Any updates sent to MassGIS will be forwarded to DEP and incorporated into this data layer. Please reference the orw_name, orw_type and major basin identifier when providing updates.

Last Updated 2/3/2009
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