Central Columbia Plateau - Yakima River Basin Active

National Water-Quality Assessment (NAWQA), Central Columbia Plateau-Yakima River Basin

Problem – In 1991, Congress established the National Water-Quality Assessment (NAWQA) Project to address where, when, why, and how the Nation's water quality has changed, or is likely to change in the future, in response to human activities and natural factors.

Central Washington contains some of the most productive agricultural land in the United States. The USGS learns about the effects of agricultural practices on water quality by studying the CCPK region.

Major issues to be addressed include:

Sources/Usage: Public Domain.

• Understanding the effects of pesticides and other contaminants on aquatic biota.
• Predicting how reductions in inputs of pesticides and nutrients to surface waters affect their concentrations at downstream locations.
• Determining the pathways by which nutrients and pesticides are entering surface waters via the ground-water system.
• Understanding how the implementation of agricultural management practices affects water quality.

Objectives - The long-term goals of the Central Columbia Plateau-Yakima River Basin NAWQA study are to provide a nationally consistent description of current water-quality conditions in the Study Unit, define long-term trends (or lack of trends) in water quality, and identify, describe, and explain, insofar as possible, the major factors that affect observed water-quality conditions and trends.

Relevance and Benefits - An important part of the USGS mission is to provide scientific information to manage the water resources of the Nation. The USGS established the National Water-Quality Assessment (NAWQA) Program to:

• Describe the status and trends in the quality of a large, representative part of the Nation's surface-water and ground-water resources using nationally consistent methods and approaches. 
• Provide an improved understanding of the primary natural and human factors affecting these conditions.
• Provide information that supports the development and evaluation of management, regulatory, and monitoring decisions by other federal, state and local agencies.

Three major program elements contribute to accomplishing the goals of the NAWQA Program:

• Investigations of major river basins and aquifer systems, referred to as study units. 
• Regional and national syntheses of key findings from study-unit investigations and existing information related to important water-quality topics such as pesticides, nutrients, volatile organic compounds, trace elements, and ecology.
• Coordination at local, State, regional, and national levels with environmental and natural resource managers and other users of water-quality information.

The data and information provided by the NAWQA Project in this State are vital to the NAWQA Program nationwide.

Sources/Usage: Public Domain.

Approach - To adequately address water-quality issues at the national scale, an integrated program of water-resources investigations that is consistent at all scales is required. In contrast with many previous water-quality studies, we will analyze loads as well as concentrations of chemical constituents to help assess the impact of the chemicals resulting from natural processes or man-made effects. We will consider seasonal variations both from the standpoint of climate and agricultural practices. In order to determine the mechanisms causing water-quality degradation, we will search for areas with nearly homogeneous land-use and hydrologic conditions where the incoming and outflowing water quality can be compared.