This Subwatershed is divided into two Minor Watersheds: 14001 and 14003 (thick red lines). Each, in turn, is subdivided into Hydrologic Units (thin black lines) - not to be confused with the USGS' Hydrologic Units. In cases where a Minor Watershed contains lakes 100 acres or larger or stream gages, the DNR felt that further partitioning of the Minor Watersheds was necessary. The resulting Hydrologic Units are the basic building blocks of the watershed system now used by the DNR.
In this example, three of these encompass the land areas that immediately drain into Nelson, Fish and Twin Lakes, respectively (and are also called 'Lakesheds'). The southern-most Hydrologic Unit (1400300) contains the area drained by the stream that connects Twin Lakes to Lake Miltona. The northwestern Hydrologic Unit (1400100) is equivalent to it's antecedent Minor Watershed (14001) because no further partitioning was deemed necessary.
The map shows that each Hydrologic Unit is given a 2-digit code in addition to it's 5-digit Minor Watershed number (e.g. 14003 + 01). The DNR's original Major and Minor Watershed system was developed independently from the USGS' HUC system to better fit it's smaller scope (statewide vs. nationwide). Because of this, the DNR's watershed numbering system is less complex and it contains fewer hierarchy layers. For more information see History and Standards of Watersheds in Minnesota.
Go back to Subwatersheds (HU Level 6)
Go back to Watershed Main Page