Strategic Planning for Water Rights Acquisitions in the Columbia Basin: an Assessment of Regional Streamflow Response to Climate Change

Abstract

The Columbia River Basin provides numerous water-ecosystem services through its natural flow regime. Wildlife in the basin, including salmon, are evolutionarily adapted to changes in the seasonality of the river’s flow. The quality, quantity and timing of flow directly influence the productivity and resilience of salmon populations. Although salmon can adapt to some natural drought conditions, cumulative human impacts over the last century, including flow diversions for irrigation and hydroelectric dams, have drastically altered the natural flow regime. As a result, some salmon populations face possible extinction. NOAA and other federal agencies have collectively allocated more than $3.3 billion to address dwindling salmon populations by conducting restoration activities and issuing biological opinions (BiOps) that contain suggested mitigation measures. In 2002, the National Fish and Wildlife Foundation, along with other non-profit organizations, introduced a market-based approach that may improve salmon conservation outcomes, and reduce federal spending: facilitating water right transactions that keep water instream for salmon in critical habitat areas. While these market-based approaches hold great promise, organizations are limited in their decision-making capacity due to insufficient information about the future state of hydrology in the basin. Climate change projections indicate that certain sub-basins may experience changes in the timing and amount of streamflow due to decreased snow pack. For that reason, we are using a multi-model approach (Global Circulation Models, Variable Infiltration Capacity model and the Water Evaluation and Planning model) to evaluate possible climate-induced shifts in the future hydrology of selected sub-basins. Results suggest that strategic water rights transactions can help mitigate the negative effects of climate-induced drought on salmon populations and enhance the water-ecosystem services that are a product of the natural flow regime in the Columbia Basin. Ultimately, we will make recommendations to organizations within the water governance system in order to strategically focus future water rights transactions.