WBD HU4 0109 Massachusetts-Rhode Island Coastal Updates

Release Date:

The Watershed Boundary Dataset has been updated in several areas along the Massachusetts and Rhode Island coast. Updates for this area are included in the latest version of the WBD data available via the National Hydrography Dataset website.

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Figure 1. Extent of WBD HU4 0109. Red arrows depict general flow direction within this frontal coastal area.

(Public domain.)

 

WBD HU4 0109 represents the coastal drainage areas along the Massachusetts and Rhode Island coast extending from the Merrimack River to the north and the Long Island Sound to the south (Figure 1). Coastal frontal areas within the WBD represent multiple hydrologic systems that contribute to the same coastal feature such as a particular ocean, bay or sound. Currently, WBDHU4 0109 has areas contributing flow to both the Atlantic Ocean and Long Island Sound (Figure 1).

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Figure 2. Overview of WBD HU8 01090005 with general flow direction represented by the red arrows.

(Public domain.)

 

 

 

 

 

 

 

 

Upon further investigation it was discovered that 8-digit Hydrologic Unit (WBD HU8) 01090005: Pawcatuck-Wood represents the drainage areas for Wood River (HU10 0109000501) and Pawcatuck River (HU10s 0109000502 and 0109000503) which flows into Long Island Sound as well as the frontal area flowing into the Atlantic Ocean  and Block Island (HU10 0109000504). (Figure 2)

 

 

 

 

 

 

 

 

 

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Figure 3. Overview of the updated hydrologic unit codes and names for the new Pawcatuck River HU8 unit (01100007: Pawcatuck River) and Block Island, Atlantic coastal area HU8 unit (01090006: Point Judith-Block 

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Through collaboration and coordination efforts with USGS Hydrography Leads, WBD National Technical Coordinators, WBD State Stewards, State and Local partners it was decided that WBD HU4 0109 and WBD HU4 0110 would be updated so HU4 0109 would represent areas flowing into the Atlantic Ocean and 0110 would represent areas flowing into Long Island sound. In order to accomplish this HU8 01090005 would be retired and the Wood River and Pawcatuck River HU10 units would be moved into a new HU8 unit 01100007 and the remaining portion of 01090005 would be grouped into a new frontal HU8 unit 01090006 (Figure 3). Table 1 represents the original hydrologic codes and updated codes for this region.

 

 

 

 

Table 1. Hydrologic Code and Name crosswalk. This table represents the original hydrologic unit codes and names as well as the updated hydrologic unit codes and names for 010900005

Original HU Code Original Name Updated Code Updated Name
1090005 Pawcatuck-Wood 1090006 Point Judith-Block Island
1090005 Pawcatuck-Wood 1100007 Pawcatuck River
109000501 Wood River 110000701 Wood River
109000502 Upper Pawcatuck River 110000702 Upper Pawcatuck River
109000503 Lower Pawcatuck River 110000703 Lower Pawcatuck River
109000504 Block Island-Frontal Block Island Sound 109000601 Point Judith Pond-Frontal Block Island Sound
109000504 Block Island-Frontal Block Island Sound 109000602 Block Island-Block Island Sound
10900050101 Upper Wood River 11000070101 Upper Wood River
10900050102 Lower Wood River 11000070102 Lower Wood River
10900050201 Chipuxet River-Pawcatuck River 11000070201 Chipuxet River-Pawcatuck River
10900050202 Usquepaug River 11000070202 Usquepaug River
10900050203 Beaver River 11000070203 Beaver River
10900050204 Usquepaug River-Pawcatuck River 11000070204 Usquepaug River-Pawcatuck River
10900050205 Tomaquag Brook-Pawcatuck River 11000070205 Tomaquag Brook-Pawcatuck River
10900050301 Ashaway River 11000070301 Ashaway River
10900050302 Shunock River 11000070302 Shunock River
10900050303 Outlet Pawcatuck River 11000070303 Outlet Pawcatuck River
10900050401 Saugatucket River 10900060101 Saugatucket River
10900050402 Point Judith Pond-Frontal Block Island Sound 10900060102 Point Judith Pond-Frontal Block Island Sound
10900050403 Ninigret Pond-Frontal Block Island Sound 10900060103 Ninigret Pond-Frontal Block Island Sound
10900050404 Block Island 10900060201 Block Island
10900050405 Rhode Island Sound-Block Island Sound 10900060202 Rhode Island Sound-Block Island Sound
10900050406 Point Judith Harbor of Refuge-Block Island Sound 10900060104 Point Judith Harbor of Refuge-Block Island Sound