Effects of Climate Change on Snowpack, Glaciers, and Water Resources in the Northern Rockies

Abstract

Many of the effects of climate change on ecosystems will be mediated through changes in hydrology. Decreasing snowpack and declining summer flows with warming will alter timing and availability of water supply, affecting agricultural, municipal, and public uses in and downstream from national forests. Declining summer low flows will affect water availability during late summer, the period of peak demand for irrigation and power supply. Increased magnitude of peak streamflows will damage roads near perennial streams, ranging from minor erosion to extensive damage, thus affecting public safety, access for resource management, water quality, and aquatic habitat. Primary adaptation strategies to address changing hydrology in the Northern Rockies include restoring the function of watersheds, connecting floodplains, reducing drainage efficiency, maximizing valley storage, and reducing hazardous fuels. Tactics include adding wood to streams, restoring American beaver populations, modifying livestock management, and reducing surface fuels and forest stand densities. Primary strategies for infrastructure include increasing the resilience of stream crossings, culverts, and bridges to higher peak flows and facilitating response to higher peak flows by reducing the road system and disconnecting roads from streams. Tactics include installing higher capacity culverts, and decommissioning roads or converting them to alternative uses. Erosion potential to protect water quality can be addressed by reducing hazardous fuels in dry forests, reducing non-fire disturbances, and using road management practices that prevent erosion.