watervulnerability

Coconino National Forest Watershed Vulnerability Assessment, Southwest Region (R3)
Sensitivity of each subwatershed to change, including hydrologic changes that might result from a
changed climate, was determined for each resource value by considering natural and anthropogenic
factors most important in affecting the condition of these watersheds. In this exercise, the team assigned
weightings to each factor based on professional judgment. Both stressors (factors that negatively impact
condition) and buffers (factors that improve condition) were included. Factors for each resource, with
their respective weights, are listed in Table 5.
Of note is the importance of instream water rights as a buffer to possible impacts of climate change.
Water rights are highly weighted buffers for five of the six water resource issues. Forest efforts in
acquiring these rights substantially increase the chance of maintaining critical water resource values.
Condition Factor
Water Resource Issues
147 Assessing the Vulnerability of Watersheds to Climate Change
Herpetiles
Warm Water Fishes
Streams
Riparian/Springs
Water Uses
Infrastructure
Data Source
Riparian Vegetation 4 4 4 4 WCA
Disease (chitrid) 4 Forest Data
Invasive aquatic species 5 5 WCA
Terrestrial Vegetation Condition 4 4 4 1 3 WCA
Wells, Water Diversions, and Developments 5 4 5 5 5 Professional Judgment
Invasive Riparian Species 2 3 3 WCA
Wildfires (severe, within last 5 years) 3 3 3 3 5 Forest Data
Road Proximity 3 4 4 2 Forest GIS
Basin Size 4 Forest GIS
Road Density 3 Forest GIS
% Watershed Urbanized 4 WCA
% Watershed >40% Slope 3 Forest GIS
Regional/National Groundwater Policy (b) 3 2 3 Professional Judgment
Instream Water Rights (b) 4 4 4 4 3 Forest Data
Invasive Species Removal (b) 5 Professional Judgment
Barriers (natural or constructed) (b) 4 Forest Data
BAER Treatments (b) 3 Forest Data
Table 5. Condition factors (with weightings) for each water resource. Factors that buffer condition are indicated by (b).
A single score for each watershed was derived by multiplying each factor times its weight, and adding the
sum of the stressors together. The sum of buffers, multiplied by their respective weights, was subtracted
from the buffer sum. These values were then ranked and the highest third rated as having “high”
sensitivity, the lowest third were placed in the “low” sensitivity class. Results of this classification are
available at www.fs.fed.us/ccrc/wva/appendixes. An example (relative watershed sensitivity for stream
habitat) is shown in Figure 17.