watervulnerability

White River National Forest Watershed Vulnerability Assessment, Rocky Mountain Region (R2)
sensitivity is an artifact of its inherent characteristics, such as geology, elevation, precipitation, etc. In
other words, we can’t affect most of the attributes that influence resiliency. Therefore, the focus narrows
to the few things that management can actually affect – the anthropogenic influences such as water uses,
roads, and vegetation management.
In the subwatersheds with the highest sensitivities, any activity that maintains or increases water quantity
or runoff timing would ultimately be beneficial. Specific actions could include contesting new water
rights proposals, exploring ways to convert existing water rights into instream flows, and anticipating
storage proposals (which are likely to increase in both size and frequency).
This analysis could also help guide implementation of our travel management plan by directing where
roads should be decommissioned or where reconstruction/maintenance should be scheduled to
hydrologically disconnect roads from the stream network. Similarly, this analysis could also help
prioritize aquatic organism passage projects at road-stream crossings to ensure that aquatic residents are
able to migrate to suitable habitat as streamflow and temperatures change. Selecting the subset of high
vulnerability watersheds in high pine beetle mortality areas would also help prioritize road-stream
crossings for upgrades relative to floods and debris.
Lastly, with a half million acres of pine beetle mortality on the Forest, the results of this analysis could
help direct where active vegetation management could benefit the recovery process by enhancing natural
reproduction, hydrologic recovery, stream shading, and future large woody debris recruitment.
Integration with the Watershed Condition Framework Process
The recently completed process for the watershed condition assessment ended with a condition rating for
each subwatershed on the forest. There were 12 attributes that were rated, but the following subset of
those could be directly affected by climate change:
• 1.2 - Water Quality Problems
• 2.1 - Water Quantity
• 4 - Aquatic Biota (Exotics and Invasives)
• 10.1 - Vegetation Condition
• 12 - Forest Health (Insects and Disease)
Changes in runoff from climate change would have direct effects on water quantity (attribute 2.1), and
indirect effects on water quality (attribute 1.2) as dilution flows diminish. Less runoff may also mean
more indirect effects on aquatic and riparian biota (attribute 4.0), because exotic species tend to compete
well in environments with modified flows and temperatures.
Changes in air temperature and the distribution of precipitation types would eventually affect the
distribution of vegetation types and the overall vegetation condition (attribute 10.1). Local experience
with the mountain pine beetle has shown that insects and diseases (attribute 12) can propagate in
unexpected ways with small changes in air temperature.
Since the Watershed Condition Framework assessment and this climate change vulnerability assessment
were both conducted at the subwatershed scale, they are easily integrated. Identifying areas where
diminished watershed condition attributes overlap with high climate change vulnerability can help target
restoration priorities.
127 Assessing the Vulnerability of Watersheds to Climate Change