ture of the dam removal’s impact. They were downriver from the 173foot earthen structure of Iron Gate Dam, the last in the process of being deconstructed.The riverruns mostly east-west in this stretch, so the canyon walls were no match for the bright, rising sun. Tullos and other Oregon State project leaders were about halfway through a three-year project funded by Oregon Sea Grant. It braids Western science with traditional and Indigenous knowledge to clarify how water quality management affects everything from recreation to tribal fishing. The framework they develop will inform future water management decisions. The team inflated their kayaks, loaded them with gear and set off. About 30 minutes later, they spotted a patch of aquatic plants, or macrophytes, and pulled over to take samples.The macrophytes stretched out for about 100 feet, creating a long, string-like layer of green and yellow that swayed in the current. Tullos walked through sludge-like sediment. Soon she was up to her shoulders in the water, surrounded by macrophytes. “You look like you are taking a swamp bath,” Issi Tang, a master’s student in water resources engineering, said from the shore. A few minutes later, the team identified a sample location.They pulled out a 1.5-foot square sampling frame made of PVC pipe. The area inside the pipe is the sample zone. They recorded GPS coordinates. Tullos used a ski pole to measure water depth. Then, with help of printouts of different macrophytes, she identified the type and amount of each in the sample zone. Lily Bell, an undergraduate ecological engineering student, measured water velocity. Tang recorded the numbers on a clipboard. They repeated this process dozens of times. There’s not much data about what happens to water quality after dams come down. The team’s exacting work aims to remedy that. “Water quality changes impact aquatic plants and algae, and those are important because they impact P.35 things we care about, like fish and fishing,” Tullos said. “There’s a sort of scientific gap around how water quality and these algae and plants are connected. We have this opportunity to learn as the system is undergoing big changes, and that will help us understand these same dynamics in other rivers.” The importance of water quality is “really underappreciated,” Tullos said. “Part of the reason people ignore it is because it’s really complicated — it’s really complex.” She and her team were already finding that some of their assumptions were wrong. They understood murky water would impact the growth of aquatic plants, because light can’t penetrate the water deeply. So they were surprised to find plants thriving in dark waters early in the season. The dam removal demonstrated that another important factor — the elimination of spring floods — may allow aquatic plants to get an earlier start in summer. This is relevant to rivers across the West where flood regulation has resulted in fewer high flow events and aquatic plants appear to be gaining ground. D During much of the 20th century, river engineering meant building dams to generate power, control floods, store water or make passage easier. Dams brought cheap electricity, opened agricultural opportunities and drove regional growth. The 1935 Beaver yearbook, dedicated to the construction of the Bonneville Dam on the Columbia River, summed up the pride felt then: “No matter what the potentialities of nature, man alone has been able to gain the knowledge necessary to harness the natural power sources of the world and to make possible a new age of industrial development for civilization.” Today, river engineering focuses on rivers as systems and often involves undoing what was done in an attempt to restore more natural conditions. Building has made way for unbuilding. The four dams affected by this project were constructed between 1918 and 1962. They electrified the region for the first time and allowed for economic development and growth. Two of the main reasons they were targeted for removal were to improve water quality and establish better fish passage. But economics are also critical.As with many aging dams, the cost to improve them was no longer justified by the financial return of operating them. In recent years, the dams made up less than 2% of the power generated by PacifiCorp, the utility that operated them. “This is a test bed for how we deal with aging infrastructure in a way that is socially and environmentally responsible,” Tullos said. “In that way, it is a profound example.” Mark Bransom, ’91, M.S. ’94, Ph.D. ’97, the CEO of the Klamath River Renewal Corporation, has been working on the Klamath project since 2017. His company is in charge of the demolition of the dams as well as the acres that surround them, which will eventually be transferred to the states of California and Oregon, or another designee, after the restoration is complete. “This is a test bed for how we deal with aging infrastructure in a way that is socially and environmentally responsible.”
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