This datalayer delineates those watershed areas in which some resources may be afforded Outstanding Resource Waters classification under the Massachusetts Surface Water Quality Standards of 1995. 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." (March 1, 1995). In ArcSDE are two layers - ORW_POLY and ORW_ARC The original source materials for this datalayer correspond to the MassGIS drainage subbasins and Areas of Critical Environmental Concern (ACEC) datalayers. Additional water supply watershed information was gathered from overlaying existing data onto USGS 1:25,000 quads and delineating additional watersheds.
REQUIRED: The basis on which the time period of content information is determined.
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. Furthermore, the scale and source materials for this datalayer are far coarser then that at which most specifically regulated activities and resource issues should be examined. Because the watershed delineations used for this datalayer are an interpretation of contour data their spatial accuracy can be no better, and, in locations with little contour information represent considerable professional judgment. This data has not been field checked. For areas near watershed boarders or anytime there is a question, field observation and/or site specific information should be consulted.
The entire datalayer was check plotted by MA DEP and quality checked by MA DEP Wetlands Conservancy Program staff.
The existing MassGIS drainage subbasin datalayers were plotted on Mylar at 1:25,000 scale with the surface water withdrawal points from the MassGIS public water supplies datalayer. The basins of the surface water supplies were identified and if necessary additional drainage basins were delineated from the intake points of public water supplies. From these basins all upstream basins were coded as contributing to a surface public water supply. These basins were compared against the Massachusetts Surface Water Quality Standards of 1995 to determine which basins were designated as containing Outstanding Resource Waters (ORW). Additional areas added included ACECs, 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.
Internal feature number.
In order to differentiate between ORW areas protected because of public drinking water supplies and other areas, the field ORW was added to the ORW_POLY attribute table
ORW contributing area of a public surface water supply
ORW for ACEC
ORW for both Water Supply and Other
Area of feature in internal units squared.