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This datalayer delineates areas in which certain waters are afforded Outstanding Resource Water (ORW) protection under the Massachusetts Surface Water Quality Standards, 314 CMR 4.00 (WQS). According to 314 CMR 4.04(3): "Certain waters are designated for protection under this provision in 314 CMR 4.06. These waters include Class A Public Water Supplies (314 CMR 4.06(1)(d)1.) and their tributaries, certain wetlands as specified in 314 CMR 4.06(2) and other waters as determined by the Department based on their outstanding socio-economic, recreational, ecological and/or aesthetic values. The quality of these waters shall be protected and maintained."
It is important to note first, that the areas delineated in this datalayer are not themselves ORWs, and, second, that only certain waters within the delineated areas are ORWs. Additionally, while the WQS designate Massachusetts Division of Fisheries and Wildlife as ORWs, certified vernal pools are NOT included in this datalayer (see 314 CMR 4.06(2)). Further, there may be areas not shown in this datalayer that contain ORWs.
In ArcSDE the layer is ORW_POLY.
The Massachusetts Surface Water Quality Standards are the definitive and sole official source of ORW designation of surface waters. It is critical, therefore, to review the WQS to determine which surface waters are, in fact, ORWs: http://www.mass.gov/eea/docs/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 that were selected to match the enabling legislation. The Elizabeth Islands shoreline was also derived from the DEP Wetlands datalayer and buffered 1,000 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 WQS to determine which areas contain ORWs. Additional areas depicted as containing ORWs include drainage basins of certain protected scenic rivers, certain protected wetlands areas and certain areas that contribute to Rhode Island public 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 as ORWs, 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.
Again, the sole official designation of ORWs is through the Massachusetts Surface Water Quality Standards. Other protections of specific surface waters resources are provided by and through the application of other DEP 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 the Wetlands Protection Act, among others. Other MA regulations and, in some cases, local bylaws or ordinances, provide additional protections.
This datalayer only serves to highlight areas (and not necessarily all such areas) where ORW issues may arise and, therefore, should be more specifically evaluated. 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 discontinuous but are represented by multipart polygons, areas given are for the entire feature.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 discontinuous 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:
Cape Cod NS
Public Water Supply (Watershed and RI)
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)
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 6/25/2015