watervulnerability

Grand Mesa, Uncompahgre and Gunnison National Forest Watershed Vulnerability Assessment, Rocky
Mountain Region (R2)
Figure 8. Infrastructure Values Ranking
The Upper Taylor geographic area has the largest area in a high ranking for infrastructure values. The
Cochetopa geographic area has the second largest area in high infrastructure values ranking, due primarily
to road and trail stream crossings and miles of routes within riparian areas. The San Juans geographic area
has the third highest amount of area in a high ranking for infrastructure values, mostly due to the density
of road and trail stream crossings, with a few subwatersheds having a higher density of developed sites
within riparian areas. The Uncompahgre geographic area has the lowest ranking for infrastructure values.
Water Uses Values
An initial purpose of the National Forest system was and remains to “secure favorable conditions of water
flows.” Many water use values depend upon the runoff generated from the GMUG. Those values are
realized both on and off the Forest. Water use values are both consumptive and non-consumptive. For this
WVA, both public and private water uses were evaluated, and are listed below.
Water Rights Quantification - acre feet per acre of subwatershed for water storage rights, or cubic feet
per second per acre of subwatershed for water flow rights. Water rights included were those held by the
US Forest Service, municipalities and other public entities, as well as private individuals and water user
groups. Water uses associated with these rights are primarily for irrigation and stockwater, with some
domestic water use. Data used to identify water rights originated with the State of Colorado Division of
Water Resources. The state’s Division 4 overlaps all but the northern half of the Grand Mesa on the
GMUG, which is within the State’s Division 5. Data for Division 4 included water rights/uses both on and
off National Forest system land; Division 5 data used in this analysis were only for National Forest
system land on the GMUG. Only actual, developed water rights were included. Water rights exist for
approximately 1,704,070 acre feet of storage (quantification of water rights in acre feet per acre of
subwatershed ranged from 0 to 79) and 24,620 cubic feet per second flow (quantification of water rights
74 Assessing the Vulnerability of Watersheds to Climate Change