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Water-Quality Monitoring and Modeling of the Keno Reach of the Klamath River

Objectives

image: Lake_Ewauna.jpg
Aerial photo of Keno impoundment
(Photo by T. Roninger, USFWS, 24-Aug-2006)

A better understanding of water quality and instream processes in the Keno reach is needed in order to better manage the system and to create restoration strategies. The specific objectives of this study may be summarized as follows:

  • Identify and characterize the most important processes influencing water quality in the Keno reach of the Klamath River, including the spatial and temporal scales over which those processes operate.
     
  • Through directed research efforts, characterize and quantify the influence of bacteria and algae on water quality in the Keno reach.
     
  • Develop or modify a water-quality model for the Keno reach that includes the most important instream water-quality processes, is sufficiently accurate in its portrayal of those processes, and is useful for assessing the utility of proposed management alternatives.

Approach

A wide range of data is required to evaluate water-quality conditions and to support analytical modeling in this complex reach of the Klamath River. Flow data, including inflows, diversions, and stage data are required to assess the water budget and determine hydrodynamic controls on water quality. Water temperature and water-quality constituents collected at multiple locations will help to characterize spatial and temporal variations in water-quality conditions. Meteorological observations are necessary to determine heat exchange at the air-water interface and to quantify wind mixing processes. Experimental work will focus on understanding the health of algae, settling of organic matter, and bacterial activity in the reach. Together, these data will be used to formulate a conceptual model, evaluate existing models, and aid in the selection of the most appropriate model to evaluate scenarios with the goal of characterizing and improving water quality in the reach.

Flow and Water Temperature

In order to understand water quality in this reach, it is first necessary to quantify the flow through the system and characterize the river's heat budget. Flow and water temperature data are needed for the inflows to the river reach, including point sources, and not all of these are being measured. Flow data for the major outflows, including the Lost River diversion channel, North Canal, Ady Canal, and Keno dam will also be needed.

USGS and Reclamation will conduct synoptic flow measurement studies from Link River to Keno Dam. Special techniques will be employed in areas of slow-moving water. Characterization during wind events may be considered. During the synoptic flow measurement studies on the Klamath River, discharge measurements will be made on selected inflows, to provide some point checks on discharge records.

Continuous Water-Quality Monitors

Water-quality conditions vary greatly in the Keno reach over the course of a day and over time scales of weeks to months. In addition, important variations in water quality exist with distance downstream from Upper Klamath Lake. One good way to characterize these spatial and temporal patterns, and also gain insight into the nature of the processes affecting water quality, is to deploy continuous water-quality monitoring instruments at many locations. Such data are also critical to the calibration of water-quality models and for assessing their accuracy.

Water-quality monitors have been deployed and maintained by Reclamation personnel at sites in the Keno reach in the past. For this study, this monitoring network will be expanded to include 12 instruments deployed at 8 sites, measuring hourly data for water temperature, dissolved oxygen, pH, and specific conductance. Reclamation and USGS personnel will collaborate on protocols to ensure the highest possible quality of the collected data. USGS procedures will be applied to correct the measured data for the effects of fouling and calibration drift. The final data will be stored in the USGS database and will be made available to the public via a USGS web site.

Water-Quality Samples

To understand the dynamic processes that contribute to poor water quality in this reach, a comprehensive suite of water-quality constituents, including nutrients (nitrogen and phosphorus) and algae, need to be measured from spring through autumn and at sampling intervals less than the travel time through the Lake Ewauna to Keno reach. This dataset will be critical for supporting model development and calibration, as well as helping to discern controlling instream water-quality processes.

Samples will be collected for the March through November time period at at least 5 main-stem sites as well as a couple major inflows. Samples will be collected approximately once every two weeks in March and November, and weekly in April through October. All general chemical samples will be analyzed at the USGS National Water-Quality Laboratory in Denver, Colorado. Specialized samples for biochemical oxygen demand, plankton identification and enumeration, stable isotopes, dissolved organic carbon, and bacteria will be handled by other laboratories. Special synoptic sampling events will be planned as necessary depending on river conditions.

Quality assurance / quality control plans will be established and implemented according to Reclamation and USGS policies. Reclamation personnel will assume the bulk of the field work associated with sample collection, following USGS sampling protocols and with periodic assistance from USGS and Watercourse Engineering staff.

Meteorology

Due to a lack of wind data at the western edge of the study reach, and because that area tends to have higher winds than the eastern side, an additional meteorological station will be established by Reclamation personnel at or near Keno.

Experimental Work & Research

Specific research efforts will be conducted to assess algal primary productivity and algal health, the settling of suspended material, and the role of bacteria in carbon processing, oxygen depletion, and other processes. Researchers from USGS, Watercourse Engineering, and the University of Nevada at Reno will participate in these efforts.

Model Development

The data collection and experimental work will help build a conceptual model of flow and water-quality processes between Link River and Keno Dam. This conceptual model will be crucial in the development and calibration of a numerical model that simulates the major processes affecting water quality in this reach. The model will allow investigation of the effects of changes in flow or water levels, treatment wetlands, and changes in the composition (nutrients, organic carbon, algae) of the inflows, as well as other relevant simulations.

USGS and Watercourse Engineering personnel will collaborate on the model development. An existing CE-QUAL-W2 model is available for the study reach, having been developed by Watercourse Engineering for PacifiCorp for their FERC relicensing process, and subsequently used for TMDL development by the Oregon Department of Environmental Quality and others. This existing model will be reviewed and assessed in light of a range of potential management strategies, including modification of boundary conditions (e.g., impact of treatment wetlands), operation of the reservoirs (e.g., drawdown), and other activities. It is envisioned that the existing model can, at a minimum, be used as a screening tool.

Model updates or modifications may be used to refine the existing calibration and adjust and use the model in the light of newly collected data. Based on the review and tests, a different model may be selected and developed. Sensitivity analyses and scenario testing will be used to explore the efficacy of proposed management strategies or point the direction of future data collection. Field data and the outcomes of field experiments will be used to assess the efficacy of the existing model, and recommendations for future modeling efforts will be provided to Reclamation. A three-dimensional hydrodynamic model may be set up and used to evaluate the relative importance of lateral circulation patterns on water-quality processes in this reach.

 

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Page Last Modified: Monday - Dec 19, 2016 at 20:05:51 EST