Impact of dams up for debate
Once upon a time, hydroelectric dams were considered the enemy.
Around 1970, a group of Portland teenagers formed Students for Oregon’s Environment. We took on several “villains,” among them federally constructed dams along the Columbia River that posed barriers to salmon migration.
I left Oregon to go to college, assuming that others would resolve the problem.
Some years later, I attended an Earth Day picnic sponsored by an East Bay environmental organization. This group was focused upon the removal of old flood-control dams which were preventing fish from swimming beyond the San Francisco Bay up creeks to spawning grounds. I could not believe that people were still talking about this topic after all these years.
Was I in for further surprises!
As some Act Locally readers may recall, in the past few columns I consulted various charts provided by the Oregon Department of Energy (ODOE). I noted troubling data indicating that wind power and solar power contributed fairly low percentages to Oregon’s combined electrical output. Because numbers vary from chart to chart within the same ODOE report, I have become hesitant to offer definitive figures; however, what is apparent from these charts is that the state’s single largest energy sector is hydroelectric power (while wind only produces somewhere between 6.5%-11% and solar, less that 1%).
The reasons for these percentages are complex, and call for a column all their own. However, the topic of hydroelectric dams is worthy of separate consideration.
Environmentalists find themselves taking opposing positions on this issue. Some are primarily concerned about the dams’ impact upon watershed health and migrating salmon and insist upon the dams’ removal. Others, more focused upon Climate Change, argue that hydropower offers a clean, cheap, renewable source of electricity — so the dams should remain in place. Still others voice concern that the removal of hydroelectric dams would potentially create a serious, secondary environmental hazard, as huge amounts of sediment — built up behind dams over decades — would overwhelm watersheds, with disastrous implications for wildlife.
So, why should Ashlanders care about any of this?
Ashland receives 99% of its electricity from the Bonneville Power Administration (the Oregon agency that markets electricity produced by federally owned and operated hydroelectric dams). According to a chart supplied by Ashland Electric Director Tom McBartlett, 86% of BPA’s electricity is generated by these dams.
Furthermore, Ashland’s drinking water is run through a turbine at our city-owned hydroelectric plant, on its way to being channeled into our water treatment facility. Yes, indeed. Ashland has been generating a small amount of its own electricity through a municipally operated facility, the Reeder Gulch Power Plant, since 1909. (https://www.ashland.or.us/Page.asp?NavID=31)
For thousands of years, humans have been damming waterways — to control flooding, or provide drinking water, or irrigate fields. Streams were first dammed to turn waterwheels for grinding grain about 2,400 years ago, and to produce small-scale electrical operations beginning in the 1880s. The fact that early Ashland farmers and manufacturers dammed parts of Ashland Creek is not particularly remarkable — just that our electrical plant is still operating effectively over a century later.
The problem is — as waterways become dammed, the movement of water, wildlife and minerals becomes inhibited. Naturally flowing streams are cool and oxygenated, supporting fish and other creatures. Rain runoff washes rocks and small particles of granite (called silt) down hillsides into creeks. Silt becomes temporarily deposited, creating habitat for aquatic lifeforms before being washed further downstream to end up as sand.
When running waters are dammed, silt becomes blocked and cannot move further downstream, to replace sediment that has been washed away. In reservoirs, standing water rises in temperature. Some animal and plant species thrive in this warmer water, though others, like endangered salmon, do not. Fish returning from the ocean to spawn confront waterways containing less amount of water and temperatures that can prove fatal, even before reaching dams that may be too tall for them to jump over.
Plants which favor standing water — especially algae — tend to off-gas methane (a major greenhouse gas). ACS News Service Weekly suggests: “Sediment trapped behind dams makes them ‘hot spots’ for greenhouse gas emissions. ... (S)cientists are reporting that millions of smaller dams on rivers around the world make an important contribution to the greenhouse gases linked to global climate change. ... (M)ore methane than previously believed bubbles out of the water behind small dams.” https://www.acs.org/content/acs/en/pressroom/presspacs/2013/acs-presspac-july-31-2013/sediment-trapped-behind-dams-makes-them-hot-spots-for-greenhouse.html
In simpler words, though the hydroelectric sources of Ashland’s energy may not directly emit greenhouse gasses, potentially the reservoirs behind them may be creating GHG emissions.
First, I should mention that several individuals I spoke to were not as worried about the methane issue as the above author. Ashland Public Works Director, Paula Brown, says the city checks our reservoirs on an annual basis for the presence of toxic blue-green algae, though not specifically for methane emissions. However, she feels our local reservoirs are at a high enough altitude to keep temperatures cool, so that this should not be an immediate concern.
This is not the case in all locations. In her book, Watershed Redemption, Diana Hartel, (who spoke at Bloomsbury’s on March 13) discusses how she was part of a team of litigants which, in 2009, sued hydroelectric dams along the Klamath River over reservoirs fostering toxic algae blooms and methane gas emissions. Based upon the findings of this lawsuit, the State of California did not renew the dams’ operating licenses. The 2016 Klamath Hydroelectric Settlement Agreement sets the stage for the removal of four hydroelectric dams, beginning in 2020.
As for dams on the Columbia (from which our electricity comes), no one I spoke to had even considered the methane issue. They were concerned about dams inhibiting fish migration.
To that point, it does appear our old student protests did have some effect. “Enacted in 1980, the Northwest Power Act addresses the Columbia River’s hydroelectric dams’ impact on fish and wildlife by “authorizing Idaho, Montana, Oregon and Washington to develop a regional power plan and fish and wildlife program to balance the Northwest’s environment and energy needs. ...” (https://www.idahostatesman.com/news/local/environment/article229602914.html)
Fish ladders were installed at major dams to facilitate migration. Sadly, according to recent news reports, these measures have created unintended consequences. Over the years, sea lions figured out that salmon were being halted below Bonneville Dam as they lined up to mount the fish ladder. The sea lions began swimming up the Columbia and feeding upon the waiting salmon. Recently, government employees have begun shooting these predatory sea lions.
A new set of regulations to provide more water for endangered salmon has just been agreed upon. The release of water over the dams “... would be cranked up ... during the times of day when power is not in highest demand and generating it is not as profitable. During the most profitable hours — typically during the mornings and evenings — spill would be reduced. The idea is to help salmon with higher spill, while keeping lost-power generation costs at, or potentially even below, current levels. ... For the Bonneville Power Administration (BPA), which markets public power from Columbia River Basin dams, the agreement will give the administration more opportunity to sell electricity when prices are high. Greater revenues will help BPA pay for what is believed to be the most expensive fish and wildlife program in the world in the Columbia River Basin ...”
However, “... Joseph Bogaard of the nonprofit Save Our Wild Salmon cautioned that the measures won’t be enough for the species’ recovery and said his organization and others will continue to push for removal of dams on the Lower Snake River.” (https://www.seattletimes.com/seattle-news/environment/a-new-day-for-fish-hydropower-on-the-columbia-and-snake-rivers/ )
So, does it make sense to remove hydroelectric dams altogether?
The Siskiyou County Water User’s Association objects to the removal of the Klamath River dams. Environmental engineer, Susan Miller, who serves as the group’s Technical Advisor, told me her perspective is that hydropower is the cleanest, cheapest, most effective source of electricity available. More pointedly, her organization is concerned about the silt problem.
“If the dams are destroyed, the amount of silt released will be astronomical, and it is estimated that it will take the river upward of 60 years to recover,” she said. “In the interim all the deep spawning holes will be filled in with silt and the mouth of the river at the ocean will be clogged up.”
On the other hand, Save our Wild Salmon’s Joseph Bogaard indicated to me that he is not particularly concerned about the impact that a large silt release might have upon fish (unless the silt contains high levels of toxins). He offered an example of a dam removed from the Sandy River; waters flushed sediment downstream, and the system was able to self-heal in a matter of months, not years. Salmon were able to migrate during this period, despite the extra silt.
Ashland Public Works Director, Paula Brown, suggested that because of silt-release, removing large dams would most likely be temporarily catastrophic, but no one can really predict how long it would take for a watershed to normalize.
Coincidentally, Ashland had its own experience with silt-release back in the 1980s. Until EPA regulations were established in the late ’80s, every three to five years Ashland had been “sluicing” (i.e. releasing silt build-up from) the dam feeding Reeder Gulch Power Plant. Sediment from Hosler Dam would wash downstream through Ashland Creek, Bear Creek, and into the Rogue.
According to Paula, some environmentalists were concerned that salmon migration was being impeded, so Ashland Public Works stopped sluicing, and now uses a backhoe to remove sediment. However, another set of environmentalists has conjectured that, because silt creates spawning areas for salmon, the absence of new sedimentary deposits might actually be responsible for the current drop in local salmon populations.
Seattle-based, NW Energy Coalition also looked into dam removal. Not particularly concerned about either silt release or methane, the group’s sole focus was the feasibility of replacing the power generated by four dams they want to remove along the Snake River with other types of “clean,” renewable electricity. Their study concluded that this would be possible, if sufficient numbers of wind turbines, solar panels, and storage batteries were to be constructed. (nwenergy.org/wp-content/uploads/2018/04/LSRDS-study-4-page-overview.pdf) [However, judging from current low percentages of wind and solar contributions to Oregon’s grid, I’m thinking that would be a mighty big “if.”]
Back here at home, Paula Brown mentioned that we have already removed a couple of dams along Bear Creek and Ashland Creek. Salmon currently are free to migrate up Ashland Creek to below Granite Street Reservoir — with some stopping to spawn along the way. Apparently, the Parks Department is in early discussion about whether to take out that dam as well. Spawning salmon could then swim significantly further upstream — past the water treatment plant and power plant, up to Hosler Dam — without impacting city services.
So how to Act Locally?
Whether you are 17 or 70, please recognize that, to repair the environmental damage humans have rendered upon the planet, we must find effective, if complex, solutions. In coming to these, be wary of anyone who demonizes one political perspective or another. As one interviewee cautioned me — take note of who stands to make money (be it a corporation, nonprofit, private citizen, elected official, or government employee). Watch out for those who may be manipulating data or public sympathies for their own ends. Act accordingly.