watervulnerability

Chugach National Forest Watershed Vulnerability Assessment, Alaska Region (R10)
The town of Hope (population 182) lies near the mouth of the creek; most of the residences and
development are outside of the watershed. The town is supported mainly by tourism. The historic
buildings and a modest pink salmon recreational fishery are the main attractions. Commercial miners
have claims to old tailings piles and alluvial material in the lower floodplain but activity has been
sporadic. There is no industrial, agricultural, or other large-scale use of water. The mining activities
occur at a level that does not require large diversions of water. The water supply for the town comes from
private wells.
Watershed Values
• Recreational fishing, primarily for pink salmon.
• Five species of Pacific salmon (peak counts): chinook (600), chum (892), coho (900), pink
(40,000), and sockeye (37).
• Resurrection Pass Trail in the main valley: 19 miles of trail and three Forest Service recreation
cabins. Popular for summer and winter recreation including hiking, mountain biking,
snowmachining, skiing, and snowshoeing.
• Recreational gold dredging and gold panning.
• Limited commercial mining operations on floodplain.
• Limited residential structures and tourist oriented businesses within the watershed, to which the
town of Hope is immediately adjacent.
Data Available, Data Needs
• Air temperature and precipitation collected 1979-1995. Some data are missing. Permanent station
at Moose Pass, 25 miles south.
• United States Geologic Survey Stream Gauge 1967-1986.
• SNAP program conducted by the UAF has predictions for temperatures, precipitation, and
freeze/thaw dates at a 2km scale. This was calculated with PRISM and five climate models. Online
maps and bar graphs are available for Alaska communities. Raw data is available for use with
GIS.
• Global Land Data Assimilation System (NASA 2011) has soil moisture, evapotranspiration
estimates using VIC for 1979 to present, but no future estimates yet. Different models show
conflicting results for amounts and increases in evapotranspiration rates but two of three show
increases for 1979-1991 compared to 1992-2010.
• Limited data for the stream restoration work in upper Resurrection Creek are available.
• Additional data are needed for total fish habitat and for miles of stream still disconnected from
the floodplain by tailings piles and channelization.
Resurrection Creek Sensitivity and Stressors
As with many mountainous areas, there are steep, unvegetated slopes at the higher elevations, which are
prone to snow avalanches and landslides. Avalanches occur in most of the tributary streams during winter
and spring, providing a source of colluvial sediment along the streams (Kalli and Blanchet 2001). At
lower elevations, the thick vegetation, relatively low precipitation, and low precipitation intensity and
duration reduce flashy flows, stream bank erosion, and surface erosion (Kalli and Blanchet 2001).
Human derived stressors are mostly confined to the valley floor where mining has severely altered
channels and flow patterns. Mining has affected about 2,560 acres of the floodplain along the main stem,
as well as patches along a one-half mile stretch at the mouth of Palmer Creek. The mining-caused
problems that may be exacerbated by climate change include:
289 Assessing the Vulnerability of Watersheds to Climate Change