watervulnerability

Coconino National Forest Watershed Vulnerability Assessment, Southwest Region (R3)
Infrastructure
The Forest has a relatively high density of roads, with associated stream crossings. Several campgrounds
are located within or adjacent to floodplains and may be susceptible to flood damage. In addition,
numerous forest service roads, county roads, and state highways are located adjacent to stream channels
and may be vulnerable to flooding. Characterization of the value of each subwatershed (HUC-6) for the
resource was based on the density of road crossings (data source: Forest road route and stream route
layers). Frequency distribution of the sixth field densities was used to rate each watershed as high,
moderate, or low. This rating was made after analysis of both channel crossings and miles of road within
150 ft of channels. Results showed a very high correlation (>0.90) between the frequency of road
crossings and the miles of road within 150 feet of channels. It was assumed that including the miles of
adjacent roads added little to the analysis, so the road crossing data were used for the infrastructure
resource ratings.
Figure 6. Density of road stream crossings and location of campgrounds (red triangles) within 300 ft of stream
channels. Darker colors represent highest density; grey indicates lack of data.
Campgrounds located within 300 ft of a channel were also considered (see Figure 6). Campgrounds were
not included in the infrastructure rating, because it was felt that the site characteristics of each facility,
including location of facilities, the size of the adjacent channel, etc., necessitated a site-specific risk
assessment at each facility. The infrastructure subwatershed sensitivity ratings do provide a generalized,
137 Assessing the Vulnerability of Watersheds to Climate Change