A new report that culminates a five-year study covering reaches of 37 streams in and near Baker County might offer the most detailed look at water quality ever compiled in the Powder River basin.
Certainly that’s the hope of Christo Morris and Anna Morgan.
Morris is executive director of the Powder Basin Watershed Council in Baker City.
Morgan is the nonprofit organization’s outreach and education coordinator.
The report, which Morris said should be available by mid-April for free at the Council’s Baker City office and on its website, details the test results from thousands of water samples taken at 78 spots along the 37 streams.
“This is the biggest study of its type done in the basin,” Morgan said. “It’s the first comprehensive report of its kind.”
The Watershed Council received two grants from the Oregon Watershed Enhancement Board totaling $119,000, and two grants from the Oregon Department of Environmental Quality totaling $101,000 for the five-year study, Morris said.
Morgan estimates that two-thirds of the monitoring sites are on public property. A number of landowners cooperated with the study and allowed surveyors, many of them volunteers, to check temperature gauges and take water samples along stretches of stream flowing through private land.
The study, which started in the summer of 2013 and finished in November 2017, covered five parameters:
• Water temperature; temperatures above about 75 degrees can be harmful to fish
• pH level, which measures the water’s acidity
• connectivity, a measure of the water’s salinity
• dissolved oxygen, which is a major factor for fish survival
• turbidity, which measures the amount of suspended solids in water
Previous studies, none as wide-reaching or as long in duration as the Powder Basin Watershed Council’s, found that sections of many local streams are failing to meet federal standards for at least one of the five categories listed above.
For instance, a 2012 report from the Powder subbasin (one of three subbasins in the Powder River basin) found that about 860 miles of 2,200 miles of perennial streams were out of compliance with at least one water quality standard.
(The two other subbasins included in the five-year study are Burnt River and Brownlee.)
Morgan said the data collection emphasized the period June through November. That was done in part because some streams go dry late in summer or early in fall, and in part because streams are more likely to be out of compliance, in particular for temperature, during the summer.
“That’s when streams are most vulnerable, due to the lower volumes, and when you’re going to see the most problems,” Morgan said.
Morris said the main purpose of the study is to examine five-year trends in water quality and to establish a baseline against which future data can be compared.
Although five years is the longest period of widespread and sustained water quality monitoring in the Powder River basin, it’s not long enough to allow hydrologists to assess the effects of relatively slow processes such as climate change.
“Five years is really a short time when it comes to the climate,” Morgan said.
Ideally the study will be repeated in a decade or so, Morris said.
Despite its limitations, the study happened to coincide with the severe drought of 2015.
This allowed analysts to compare that year with the wetter years immediately before and after, and that effort yielded some surprising results, Morgan said.
For instance, streams in the Powder and Burnt River subbasins generally didn’t show major fluctuations in temperature during 2015, as might have been expected considering the low streamflows and hot air temperatures that summer, Morgan said.
Th e exception, she said, was the Brownlee subbasin, where water temperatures were notably higher in 2015.
See more in the March 19, 2018, issue of the Baker City Herald.