It was 6:00 in the morning when my field tech Aleyna and I loaded up a university SUV and drove the 4.5 hours from Oregon State University to the Iron Gate Dam. Having watched the video captured of the Copco 1 dam blast and spending a large portion of the drive watching the USGS website as turbidity levels in the river creeped higher and dissolved oxygen levels sank lower, we knew we were in for a unique day of field work.
Turbidity is an optical property of water. More turbidity means less clarity in the water. In other words, if a river looks like chocolate milk, it’s very turbid.
We arrived right below the Iron Gate Dam just before 11 am and happily took in an unexpected dose of bright, warm sunshine – a rarity in the PNW during January. After tugging our waders on and organizing a heap of clunky equipment, we set our path down to the Klamath River. Water discharge was as treacherous as we expected; for you industry folks, it was around 3,200 cfs. For our non-industry friends, the river was flowing very quickly. We took turns wading slowly and carefully into the water.
Up close, the water was indeed turbid. In fact, when I submerged my palm just 2 inches into the water, it disappeared from my vision completely. When I lifted it, it was covered in a thin blanket of silt and clay that accumulated and clung to me throughout the rest of the day. Our boots grew heavier with each step into the water as the thick layer of sediment on the riverbed engulfed our shoes. It felt as if the ground itself was trying to stick us in place and prevent us from being swept downstream. This layer of sediment on the bed is relatively new and likely due to the Copco dam blast. This being my third trip into this particular river reach within the last few months, I was used to the riverbed consisting only of larger rocks, such as gravel and cobbles.
Then, we noticed the fish. Several small dead fish and crayfish were positioned along the river bank, and more were launching themselves to shore, likely in search of oxygen. This indicated that the dissolved oxygen in the river had decreased to levels that were fatal for fish in the Klamath River.
Once we greeted the river and took note of the changes that had occurred over the last week, it was time to begin sample collection which consists of filling jars with water and sediment using expensive and meticulously crafted devices, then placing even more expensive and meticulously crafted devices into the river to tell us information about the chemical and physical properties of the water. We were able to capture turbidity, velocity, dissolved oxygen concentration, photosynthetically active radiation, and water temperature. We brought several samples back to the SUV to later be analyzed in the lab for organic matter content, biological oxygen demand, and suspended sediment concentration.
When we finished our work at the site, we moved on to the next two, repeating the same system as we ventured south, collecting our last set of samples at a site that requires lugging our equipment up and down a flight of stairs (probably around 40, but it feels more like 400) built into the side of the bank.
The drive back to campus was quieter, full of idle chatter about the river, academic classes, and miscellaneous road trip topics. Both exhausted and grimy after a long day of hard work, we finally pulled into Corvallis and spend the next hour unloading equipment, setting up incubations, and cleaning silt from our field gear as the evening darkness set in. Finally, satisfied that all my day’s work was complete, I climbed into my car and headed home, wondering what the Klamath River would have in store for us next week.
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