The objective of this paper is to evaluate the application of aquatic habitat variables to water quality objectives under authority of the Clean Water Act (CWA). The project is limited to freshwater, lotic aquatic habitats in the Pacific Northwest and Alaska with an emphasis on salmonid habitat. Habitat variables were placed into one of the following categories

This report describes a study of spillway passage conditions for juvenile spring chinook salmon at Ice Harbor Dam in spring 2003. The Sensor Fish Device was used to measure conditions experienced by juvenile salmon passing over a deflector installed at the base of a spillway in the dam to mitigate total dissolved gas in the spill discharge as it enters the stilling basin. The Sensor Fish Device is a waterproof, nearly neutrally buoyant sensor package developed by Battelle with funding from the U.S. Department of Energy

In ungauged basins, predicting streamflows is a major challenge for hydrologists and
water managers, with approaches needed to systematically generalize hydrometric
properties from limited stream gauge data. Here we illustrate how a geologic/geomorphic
framework can provide a basis for describing summer base flow and recession behavior at
multiple scales for tributaries of the Willamette River in Oregon. We classified the basin
into High Cascade and Western Cascade provinces based on the age of the underlying
volcanic bedrock. Using long-term U.S. Geological Survey stream gauge records, we
show that summer streamflow volumes, recession characteristics, and timing of response
to winter recharge are all linearly related to the percent of High Cascade geology in
the contributing area. This analysis illustrates how geology exerts a dominant control on
flow regimes in this region and suggests that a geological framework provides a useful
basis for interpreting and extrapolating hydrologic behavior.

The Pacific Northwest (PNW) hydropower resource, central to the region's electricity supply, is vulnerable to the impacts of climate change. The Northwest Power andConservation Council (NWPCC), an interstate compact agency, has conducted long termplanning for the PNW electricity supply for its 2005 Power Plan. In formulating its power portfolio recommendation, the NWPCC explored uncertainty in variables that affect theavailability and cost of electricity over the next 20 years. The NWPCC conducted an initialassessment of potential impacts of climate change on the hydropower system, but these results are not incorporated in the riskmodel upon which the 2005 Plan recommendations are based. To assist in bringing climate information into the planning process, we present an assessment of uncertainty in future PNW hydropower generation potential based on a comprehensive set ofclimate models and greenhouse gas emissions pathways. We find that the prognosis for PNW hydropower supply under climate change is worse than anticipated by the NWPCC's assessment. Differences between the predictions of individual climate models are found to contribute more to overall uncertainty than do divergent emissions pathways. Uncertainty in predictions of precipitation change appears to bemore important with respect to impact on PNW hydropower than uncertainty in predictions of temperature change. We also find that a simple regression model captures nearly all of the response of a sequence of complex numerical models to large scale changes in climate. This result offers the possibility of streamlining both top-down impact assessment and bottom-up adaptation planning for PNW water and energy resources.