November 2005

Download this layer

Overview

This layer represents the eight mega-drainage basins for Massachusetts, aggregated from the Major Basins layer. The delineations were based on the level 2 (4-digit) Hydrologic Unit Codes (HUCs) from the U.S. Geological Survey. Included are delineation of the Narragansett and Thames mega-basins.

The HUC is a hierarchical, numeric code that uniquely identifies hydrologic units. Hydrologic units are subdivisions of watersheds nested from largest to smallest areas and are used to organize hydrologic data. In the 4-digit HUCs, the first two digits identify the region and the first four digits identify subregions.

The polygon layer is named MEGABASINS_POLY and the line layer MEGABASINS_ARC. Annotation is included in MEGABASINS_ANNO_BASIN.

Attributes

The polygon attribute table has the following items:
ITEM NAME DESCRIPTION
BASIN_ID 4-digit HUC
NAME Mega basin name (for informal use only - does not conform to USGS naming)
The mega basins' ID and names are as follows:
BASIN_ID NAME
0106 PISCATAQUA-SALMON FALLS
0107 MERRIMACK
0108 CONNECTICUT
0109 COASTAL
0109 NARRAGANSETT
0110 HOUSATONIC
0110 THAMES
0202 HUDSON
In the arc attribute table, the item OUTLINE is coded as follows:
ITEM NAME DESCRIPTION
OUTLINE
 
 Line type:
0 Internal megabasin boundary
1 State outline

Maintenance

MassGIS maintains the layer, although no updates are planned.
For other watershed data, see these layers:

Last Updated 11/23/2005

Recommended Content

People also viewed...

You recently viewed...

Personalization is OFF. Your personal browsing history at Mass.gov is not visible because your personalization is turned off. To view your history, turn your personalization on.

Learn more on our .

*Recommendations are based on site visitor traffic patterns and are not endorsements of that content.