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Study: Climate change and Columbia Basin streamflow

Friday, January 17, 2014
Posted by: Oregon Water Coalition

University of Washington environmental engineers are launching a new study to try to understand how climate change will affect streamflow patterns in the Columbia River Basin.

The team will look at the impact of glaciers on the river system, the range of possible streamflow changes and how much water will flow in the river at hundreds of locations in future years.

“Getting a new set of streamflow predictions factoring in climate change will help guide long-term decision-making for the Columbia River Basin,” said Dennis Lettenmaier, a UW professor of civil and environmental engineering. He is leading the project with Bart Nijssen, UW researcher in civil and environmental engineering, and Philip Mote of Oregon State University.

The Columbia River’s headwaters are in the Rocky Mountains of British Columbia, and the waterway winds about 1,200 miles through Washington and along the border of Oregon before emptying into the Pacific Ocean.

Hydroelectric dams provide cheap electricity to roughly three quarters of the Pacific Northwest’s population and help with flood control throughout the basin, particularly in the Portland metro area. It’s also an important waterway for migrating salmon, steelhead and sturgeon, and for navigation, irrigation and agriculture.

Changes in streamflow due to climate change could affect hydropower and flood control operations on the Columbia as well as fisheries management and future policy decisions, including a possible treaty renegotiation between the U.S. and Canada.

The UW researchers will use the most recent projections from the Intergovernmental Panel on Climate Change along with climate and hydrology models to come up with a dataset of streamflow predictions for Bonneville Power Administration, the U.S. Army Corps of Engineers and the Bureau of Reclamation, which jointly commissioned this study.

BPA’s Technology Innovation Office, Oregon State University and the UW are funding the study, which leverages glacier model developments from a NASA-funded interdisciplinary science project.

“Hopefully, this study will be able to better bracket the uncertainty that exists methodologically between all these climate and hydrology models. If we want to be able to plan ahead on a 20- to 50-year timescale, we need to know what range of uncertainty to expect,” Nijssen said.

The impact that declining glaciers could have on the basin hasn’t fully been studied by U.S. scientists until now, though Canadian researchers recently started to look at their role. Glaciers are receding across the region and, as temperatures warm, they will continue to melt and erode.

In 2005, glaciers covered about 420 square miles in the upper reaches of the Canadian Columbia Basin, or roughly 5 percent of that area. Twenty years before glaciers covered 490 square miles.

Melting glaciers put more water into the river system and boost its flow, but only for a period.

This short-term boost could actually benefit the river – especially during low-flow periods in the drier summer months – but only in the short term.

As the glaciers eventually disappear, perhaps as early as 2100, this added water will also disappear and further reduce already low summer flows, researchers say.

But the river’s yearly flows depend mostly on melting snowpack. Cooler spring and early summer temperatures can preserve mountain snowpack until the drier months, when water from melting snow is important to keep river flows high enough for migrating fish. As climate warms, though, the timing of when that crucial snow melts and discharges into the river also is likely to change.

“The hydrology of the Columbia River basin is really driven by winter snow accumulation and melting in the spring and summer months. When it warms up, you change that balance,” Lettenmaier said. The UW’s data could have policy implications for the Columbia River. Since 1964, a treaty between the U.S. and Canada has governed the river for hydropower production and flood control.

But starting in 2014, each country can notify the other of an intent to terminate or modify this treaty. Changes to the treaty could be implemented as early as 2024.

“We want to have the best scientific information possible to help federal agencies and other regional stakeholders in long-range decision-making,” said Erik Pytlak, manager of the weather and streamflow forecasting for the Bonneville Power Administration.

“With or without a treaty, climate change is coming. It will be beneficial for all of our partners and customers in the region to have an updated understanding of what climate change is doing to the region.”

The UW’s streamflow predictions will be publically available after the study is finished in three years. Similar studies are underway at Portland State University, also funded by Bonneville, and by climate scientists in Canada.

Columbia Basin Bulletin

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USGS: Studying impacts to rivers affected by dams

Friday, January 17, 2014
Posted by: Oregon Water Coalition

In a case study of dams on the upper Missouri River, USGS researchers have demonstrated that an upstream dam is still a major control of river dynamics where the backwater effects of a downstream reservoir begin.

In light of this finding, the conventional understanding of how a dam can influence a river may have to be adjusted to account for the fact that effects of river dams can interact with one another.

“We have known for a long time that dams have dramatic effects on river form and function,” said Jerad Bales, acting USGS Associate Director for Water. “In the past, however, the effects of dams generally have been studied individually, with relatively little attention paid to how the effects could interact along a river corridor.”

One of the greatest modifications of rivers by humans has been the construction of dams that provide valuable services such as irrigation, hydroelectric power, navigation, flood protection, and recreational opportunities. Hundreds of thousands of dams have been built worldwide, beginning for the most part in the 20th century.

The downstream effects of river dams have been well documented by previous researchers. In the presence of a dam, it can often take hundreds of kilometers for a river to adjust to its natural state. The upstream impacts of dams have also been widely considered, particularly sedimentation of reservoirs. These effects may extend upstream for many kilometers.

“In addition to documenting dramatic changes to a section of the Missouri River during the 2011 floods,” Bales continued, “the unique contribution of this important study is development of a conceptual model that establishes a framework for future studies of the many rivers affected by dams in series.”

Working with historical aerial photography, streamgage data, and cross sectional surveys in a careful analysis of the Garrison (N.D.) and Oahe (S.D.) dams on the Missouri River, the USGS researchers propose a conceptual model of how interacting dams might affect a river’s physical characteristics (geomorphology). This model applies to dams on large rivers and divides the river into various zones of predictable behavior.

The researchers also conducted a geographic analysis of dams along 66 major rivers (as listed in a standard professional reference) in the contiguous United States to determine how often dams occur in a series.

Of the rivers analyzed, 404 dams were located on the main stem of 56 of the rivers. Fifty of these rivers had more than one dam on the river creating a total of 373 possible interacting dam sequences.

The results from this work indicate that more than 80 percent of large rivers may have interactions between their dams. Given this widespread occurrence, the USGS investigators suggest that dam interaction is prevalent and should be the focus of additional research.

Columbia Basin Bulletin

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Land trust acquires Willamette conservation easements

Friday, December 30, 2011
Posted by: Oregon Water Coalition

Greenbelt Land Trust has announced the acquisition of conservation easements on more than 300 acres of Willamette River frontage property in western Oregon’s Benton County that will benefit chinook salmon, cutthroat trout, Oregon chub, Pacific lamprey, western pond turtles and red-legged frogs.

The project will permanently protect important habitat for fish and wildlife identified in the Oregon Conservation Strategy. The purchases were made through a partnership with the existing landowners, the land trust, the Oregon Department of Fish and Wildlife and funding from the Oregon Watershed Enhancement Board, the Bonneville Power Administration and the Meyer Memorial Trust.

Conservation easements allow for some traditional uses of the land, such as farming by the landowner, but permanently protect wildlife habitat. They also allow conversion of farmland to restoration and conservation purposes. The easements are effective in the Willamette Valley where 96 percent of the land is privately owned.

The 319-acre parcel includes Harkens Lake, a significant historic side-channel of the Willamette River that is critical habitat for native fish populations.

“This project is an integral part of creating opportunities for broad-scale floodplain habitat restoration on the Willamette River,” according to Ken Bierly, deputy director of Oregon Watershed Enhancement Board.

The conservation of Harkens Lake is made possible through a partnership with landowners Gary, Jenny and Steve Horning and Mark and Sherie Adams, a collaboration that will continue as the partners prepare to restore the property’s floodplain forests and riparian areas to their historic conditions. Restoration of these forests decreases erosion and flood damage from seasonal inundation throughout the 100-year floodplain.

“Our family has worked and lived on the Willamette River for five generations, which is why we take such pride in showing we can work around the river sustainably. We know the health of our crops depends on the health of the river system. Our goal for restoration is to utilize important floodplain areas to improve water quality and protect the valuable farm land that our family farm depends on,” Gary Horning said.

“This important work can only be accomplished through partnerships with private landowners, non-profits, foundations and state and federal agencies,” said Michael Pope, GLT executive director.

“We’re facing a monumental task in fish recovery and riparian restoration in the Willamette Valley, and we must all work together. We are extremely pleased to be able to complete this transaction, and grateful to all our partners who work with us to protect and restore environmentally sensitive lands.”

Funding from this project was dedicated through:

Oregon Watershed Enhancement Board through its Willamette Special Investment Partnership. The goal is to identify and implement high-priority land conservation, fish passage and habitat flow restoration projects that contribute to the enhancement of resident and migratory fish populations in the mainstem and tributaries of the Willamette River.

The Oregon Department of Fish and Wildlife Willamette Wildlife Mitigation Program which was created to manage the funds dedicated to the state of Oregon by BPA for wildlife habitat mitigation in the Willamette Valley. The agreement requires a substantial investment in wildlife and fish habitat restoration over the next 15 years.

Bonneville funding helps fulfill an agreement that Oregon made in 2010 to protect nearly 20,000 acres of Willamette Basin wildlife habitat. The agreement dedicates stable funding from electric ratepayers for 15 years to safeguard Willamette habitat for native species, supporting state efforts to protect the Willamette Basin and fulfilling BPA’s responsibility under the Northwest Power Act to offset the impacts of federal flood control and hydropower dams.

Columbia Basin Bulletin

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Researchers study White Salmon and dam breaching

Friday, November 11, 2011
Posted by: Oregon Water Coalition

A flood, loosed late October, when southwest Washington’s Condit Dam was breached has literally coated the lower White Salmon River in layers of various thickness of fine, dark sediment.

But researchers predict that the river’s own dynamics make it a prime candidate to clean itself and restore the coarser, gravelly river bed needed for native fish to spawn and rear.

“If you look at the White Salmon now…. It’s hammered,” researcher Andrew Wilcox said. “If you go there now there’s a lot of mud.”

The University of Montana assistant professor is leading a research project aimed at assessing how the river “responds” to the breaching of the dam and a return to a free flowing state.

“It’s a beautiful natural experiment,” Wilcox said of the chance to monitor how the river moves large pulses of sediment that have the potential to snuff out aquatic life.

The blasting of a tunnel through the base of Condit allowed the release of sediment that had been collecting since the dam was completed in 1913. It was estimated that between 1.6 million to 2.2 million cubic yards of sediment would be discharged into the White Salmon River immediately following tunnel’s opening.

Wilcox and one of his graduate students will monitor the lower White Salmon over the next two years to see how well it refreshes itself. The study focuses on sediment transport, or the lack thereof, as well as channel evolution, and habitat response.

The researchers will try to use the data gathered there as well as elsewhere to develop a better understanding of how ecosystems respond to such events. Information could be used in planning such events in the future. The study is being funded by the National Science Foundation.

Wilcox has been involved in similar research following the breaching of Marmot Dam on the Sandy River in northwest Oregon in 2007 and the Milltown Dam in western Montana in 2008.

“Reservoirs tend to trap sediment that is fine,” Wilcox said. When the sediment is released it tends to settle into the cobbled river bottoms that salmon and steelhead prefer for spawning, and changes the depth of pools where fish seek shelter. The study aims to monitor when, where and how that sediment is deposited, and how soon the river might mend itself. “How long do the changes last?” is a key question, he said.

“It is a system that is steep and confined and has a high transport capacity,” Wilcox said of the White Salmon. The slack water in the lowest part of the river “has less capacity to clear.”

The best thing to do is hope for a wet winter.

“It’s supposed to be a La Niña year,” Wilcox said. If the snowpack builds and strong flows develop in the spring, much of the sediment and at least some of the logs dislodged from the reservoir bottom should be swept downriver.

“I’m not going to say the system will be recovered by next summer” but the spring freshet should send it well on its way, Wilcox said.

The lower White Salmon River remains off limits as it has been since before the Oct. 26 breach, which quickly drained 1.8-mile-long Northwestern Lake. The dam is located 3.3 miles upstream from the river’s confluence with the Columbia River.

The river and its banks remains an unsafe place both above the dam in the reservoir reach and below the dam, according to PacifiCorp, which owns the dam. PacifiCorp, local law enforcement and experienced river experts are unanimous in urging the curious to stay away.

“Everyone saw the force of the river,” said Tom Hickey, PacifiCorp’s project manager. “Now downstream wherever the river narrows, there are logjams. In the former reservoir above the dam, the river is cutting through the sediment creating unstable slopes and moving debris such as buried logs as expected.

“Transported sediment is also building up in downstream areas. Working with our contractors, we have plans in place to deal with these obstructions, and they all require that everyone stay out of harm’s way and a safe distance from the river,” Hickey said.

The company’s options for clearing debris include using cranes and yarders or in some instances explosives to remove barriers. The entire area from the Northwestern Lake Road Bridge to the mouth of the White Salmon River continues to be an active construction zone and a dangerous place to be.

“We are still a long way from anyone attempting to boat the White Salmon River within the project area or downstream,” said Thomas O’Keefe, Pacific Northwest stewardship director of American Whitewater. “Those of us who know the river well urge everyone to stay safe and out of this river area until next fall when PacifiCorp has had a chance to complete the channel restoration work and address the severe hazards affecting navigability.”

PacifiCorp will continue to post updates on closures and restrictions in the Condit area as work proceeds. Go to www.pacificorp.com/condit for updates. Signs will remain posted in the immediate areas to remind the public about the closures.

Columbia Basin Bulletin

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Meteorologists: Below normal temps; above average precip

Friday, November 4, 2011
Posted by: Oregon Water Coalition

Each used a different combination of tools, climate indices and calculations, but all five meteorologists offering forecasts during a conference Oct. 29 in Portland agreed that La Niña could well influence what sort of winter the Northwest and other parts of the globe will experience.

Four of the five predicted that the winter of 2011-2012 will be wetter than normal, though none predicted a repeat of 2010-11 when stronger La Niña signals prevailed. Snowpacks across the Pacific Northwest reached near record levels when a cool, wet late winter and spring settled on the region.

The forecast presenters were among more than 350 people gathered last Saturday for the 19th Annual Winter Forecast Conference sponsored by the Oregon Chapter of the American Meteorological Society. The session was held at the Oregon Museum of Science and Industry.

La Niña conditions are occurring and expected to gradually strengthen and continue this winter, according to regularly updated forecasts from National Weather Service’s Climate Prediction Center. Those La Niña conditions, which include cooler than normal sea surface temperatures across must of the equatorial Pacific, seem to increase the likelihood that the Northwest will be colder and wetter than normal.

This winter CIG suggests that there are significantly increased odds of above average precipitation; odds favoring near normal or cooler than normal temperatures and that there are significantly increased odds of an above average snowpack, according to Dave Elson, lead forecaster for the Weather Service’s Portland office.

“La Niña, that’s really what drives this forecast,” Elson said. The agency says the region can “expect an active weather pattern this winter.”

Columbia River Inter-Tribal Fish Commission hydrologist/meteorologist Kyle Dittmer used a host of tools, including indices such as the El Nino/Southern Oscillation and the Multi-variate ENSO Index, and the Pacific Decadal Oscillation, Sea-surface temperature departure forecasts, and comparisons of past years’ La Niña outcomes (analog years), including water year volume forecasts. And he even factors in sunspot cycles (though they are currently in a relatively neutral mode), which he says can influence global weather patterns.

He predicts the Columbia-Snake river basin will be “slightly below normal temperature-wise for the season” and should see above average precipitation. Dittmer said the region can expect some variability, which might include heavy rain events west of the Cascades, flooding, arctic blasts and high wind events. And rainy Portland should expect a few snow events from December to early March, he said.

His water supply forecast for January-July 2012 as measured at the lower Columbia’s The Dalles Dam is 117 million acre feet, or 109 percent of the recent 30-year average. In October 2010 Dittmer predicted that 2011 runoff would be 129 MAF, 120 percent of normal, and that early season forecast was in the ballpark. The observed, unregulated runoff was 141.7 MAF from January through July.

Former Oregon State Climatologist George Taylor, as well as Pete Parsons and Jim Little, likened the pattern being experienced now to one that began in the winter of 2007-2008 played out in 2008-2009. That pattern saw La Niña conditions building in the 2007-2008, lapsing to neutral conditions during the late spring-summer, then rebuilding the following winter.

“That’s about as good of a match as you can get,” Parson said of the strategy of identifying start-of-year conditions from the past that might apply to the current year’s forecast. The winter of 2008-2009 started out strong with an early season dump of snow even into lower level sites such as Portland but ended up being a relatively average precipitation year overall. Parsons and Little do forecasts for the Oregon Department of Forestry.

Taylor said he expected November to be relatively benign with a transition in December into cooler, wetter conditions. He forecast December-February to be “very active” with above-average mountain snowfall for the winter; significant precipitation totals with possibility of flooding in the west, cooler than average temperatures and a good chance of low elevation snow, especially in January.

Parsons’ forecast followed the same track with above average temperatures early and weather turning stormy in December and January, followed by a cold February.

“Cold periods will have a better chance of being accompanied by snow this winter. Most mountain snowpacks should be above normal by late January-February,” Parsons’ forecast said.

Columbia Basin Bulletin

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La Niña is back with colder, wetter conditions for NW

Friday, September 16, 2011
Posted by: Oregon Water Coalition

La Niña, which contributed to extreme weather around the globe during the first half of 2011, has re-emerged in the tropical Pacific Ocean and is forecast to gradually strengthen and continue into winter.

Forecasters with NOAA’s Climate Prediction Center have upgraded the La Niña Watch to a La Niña Advisory.

NOAA will issue its official winter outlook in mid-October, but La Niña winters often see drier than normal conditions across the southern tier of the United States and wetter than normal conditions in the Pacific Northwest and Ohio Valley.

“This means drought is likely to continue in the drought-stricken states of Texas, Oklahoma and New Mexico,” said Mike Halpert, deputy director of the Climate Prediction Center. “La Niña also often brings colder winters to the Pacific Northwest and the northern Plains, and warmer temperatures to the southern states.”

Climate forecasts from NOAA’s National Weather Service are intended to give communities advance notice of what to expect in the coming months so they can prepare for potential impacts. Seasonal hurricane forecasters factored the potential return of La Niña into NOAA’s updated 2011 Atlantic hurricane season outlook, issued in August, which called for an active hurricane season. With the development of tropical storm Nate last week, the number of tropical cyclones entered the predicted range of 14-19 named storms.

The strong 2010-11 La Niña contributed to record winter snowfall, spring flooding and drought across the United States, as well as other extreme weather events throughout the world, such as heavy rain in Australia and an extremely dry equatorial eastern Africa.

Average sea surface temperature anomalies indicate the re-emergence of La Niña in the tropical Pacific Ocean.

La Niña is a naturally occurring climate phenomenon located over the tropical Pacific Ocean and results from interactions between the ocean surface and the atmosphere. During La Niña, cooler-than-average Pacific Ocean temperatures influence global weather patterns. La Niña typically occurs every three-to-five years, and back-to-back episodes occur about 50 percent of the time. Current conditions reflect a re-development of the June 2010 / May 2011 La Niña episode.

Columbia Basin Bulletin

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Agencies to plan for climate change in Columbia Basin

Friday, August 5, 2011
Posted by: Oregon Water Coalition

Three federal agencies have been collaborating on a climate change initiative launched in 2008 that called for the development of common and consistent climate change data for use in the three agencies’ longer-term planning activities for operation of Columbia-Snake hydro system for power production, and to assure safe passage up and downstream for salmon and steelhead.

During their presentation to the Northwest Power and Conservation Council, it was said that generally, a steady warming over time is expected to result in more wintertime runoff from the mountain snowpacks that rim the Columbia River basin and less spring-summer runoff.

That means that the region’s rivers will have lower flows in late summer.

“What happens is that runoff ends in August and September but as long as you have reservoir storage you’re not going to be so bad off.” Those that need to draw water from rivers in late summer, however, could run short.

Storage reservoirs may have to be drawn down earlier, in fall and winter rather than in spring, and deeper to allow for earlier refill flows.

Such runoff scenarios could lead to increased power generation in fall and winter and less generation in the late summer when energy demand is high.

“Traditionally historical climate data has been used when evaluating proposed actions; however, there is growing evidence that the global and regional climate system is changing and is expected to continue changing.”

This effort was led by the River Management Joint Operating Committee, a forum of water managers, hydrologists, and power schedulers from the three agencies.That collaboration the three agencies has produced three technical reports that identify how climate change could impact hydrology and water supplies in the Columbia River basin and the potential impacts of the operation of the 31 federal dams on the Columbia River and its tributaries. The study, called Climate and Hydrology Datasets for use in the RMJOC Agencies’ Longer-Term Planning Studies resulted in the following reports:

Part I – “Future Climate and Hydrology Datasets (completed December 2010). Collects a consistent set of future climate and hydrologic data from the Climate Impacts Group;

Part II – “Reservoir Operations Assessment – Reclamation Tributary Basins” (completed January 2011). Looks at potential climate change impacts to the USBR projects on the Yakima, Deschutes and upper Snake River subbasins, and

Part III – Reservoir Operations Assessment – Columbia Basin Flood Control 43 and Hydropower (completed June 2011). Makes projections of future reservoir elevations, outflows, power generation and spill for each of the climate change scenarios developed.

The three agencies recently completed a draft report entitled the Draft Climate and Hydrology Datasets for Use in the River Management Joint Operating Committee Agencies’ Longer-Term Planning Studies – Part IV Summary” that gives a synopsis of the findings of the three technical reports.

The report can be found at www.bpa.gov.

The Corps and Bureau are the owners and operators of the 31 hydro projects on the Columbia and Snake rivers. BPA markets and distributes the power generated from these federal dams and from Columbia Generating Station. BPA also owns and operates about 75 percent of the Northwest’s transmission system.

The dams and the electrical system are known as the Federal Columbia River Power System. Revenues collected through power rates cover the operation of these projects and the transmission system, the debt service required to repay the initial investment in the system, and contributes to other costs associated with these projects, such as the region’s efforts to protect and rebuild fish and wildlife populations in the Columbia River basin.

According to a project fact sheet, the three federal agencies will integrate the new climate change data into their ongoing modeling and planning efforts on a number of topics including:

  • The Columbia River Treaty Review,
  • Flood risk management,
  • Future fish and wildlife program needs,
  • Future biological opinions,
  • ESA and National Environmental Policy Act analyses,
  • Asset planning for the federal hydro system,
  • Future energy resource development needs,
  • Water conservation studies and measures (such as piping canals) that leave more water in-stream for fish,
  • Tributary and watershed habitat improvement projects.

Among the key findings:

  • Temperature: Northwest temperatures are expected to increase by 1 to 3 degrees F from 2010 to 2039 and by 2 to 5 degrees from 2030 to 2059.
  • Precipitation: Overall yearly precipitation changes in the study were minimal. However, some of the models showed large seasonal changes, including more extreme wet and dry periods, some wetter falls and winters, and some drier summers.
  • Snow pack: More winter precipitation would fall as rain instead of snow, producing more runoff in the winter, earlier runoff in the spring and less in the summer.
  • Annual water runoff: The January through April runoff volume is projected to exceed normal flows at The Dalles Dam by 20 to 85 percent. The June through August runoff varies between 65 and 95 percent of normal flows at The Dalles Dam. Normal flow, or the historical reference climate period, is the average of flows from 1970 to 1999. Higher January through April flows would generate more hydropower and produce more spill at most dams. Hydropower production would decline at the same time increased temperatures drive greater summer power use.
  • Flood risk management: Flood risk management procedures will need to anticipate that runoff may come weeks earlier, shifting the peak runoff from April through August to March through July. Earlier releases of water from reservoirs at the flood risk management projects may be needed to capture the early runoff. Impacts to the timing of federal hydro system operations could also impact other spring and summer objectives such as flows for fish.
  • Energy consumption: Higher temperatures in the summer will result in more energy use to cool homes and businesses. Warmer temperatures in the winter will reduce energy use for heating. BPA computed the estimated changes in energy consumption and determined that the demand for federal power from 2010 to 2039 showed increases of 1 to 3 percent in July and decreases of 3 to 4 percent in December.
  • Fish impacts: The increase in the January through April flows would result in higher generation and increased spill at most dams. The reduced flows during July and August may impact the federal agencies’ ability to meet future objectives, including flow management, intended to benefit salmon and steelhead and other fish stocks.

Columbia Basin Bulletin

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Estuary’s Salmon-eating Tern colony produces no chicks

Friday, August 5, 2011
Posted by: Oregon Water Coalition

Unless yet another freak of nature occurs, it appears that the world’s largest, and perhaps most studied, Caspian tern nesting colony will produce zero chicks this year at the lower Columbia River estuary’s East Sand Island.

The East Sand nesting site, enabled by human manipulations intended to reduce the birds’ consumption of migrating juvenile salmon, has been besieged this spring and early summer by other avian predators, most commonly eagles and gulls.

Early in August the tern colony on East Sand had a high count of 253 birds, down dramatically from a count of 8,931. The birds more than likely have left to forage elsewhere until they head south for the winter. There were no fledglings to make the trip. Only a handful of terns remained.

“All tern nest with eggs failed due to gull predation during several disturbances by peregrine falcons and bald eagles; Caspian terns were unsuccessful in rearing any young at East Sand Island this year,” a weekly research update said.

The research is a collaborative project between Oregon State University, Real Time Research Inc., and the USGS-Oregon Cooperative Fish and Wildlife Research Unit. Started in the late 1990s, the work aims to assess the impact of avian predation on recovery of ESA-listed salmonids.

“This is the first season since we started monitoring the colony that is has not produced eggs,” researcher Allen Evans said. Given the fact that it is late in the season, and most of the terns have left, there is little chance of tern production.

“It might be too early to conclude that, but I think it’s highly unlikely,” said researcher Don Lyons. It takes about 28 days for a Caspian tern to lay and incubate an egg, then another 28 to 36 days before a young bird can fly.

“We’re definitely to the point that most birds would be leaving the colony, even in a normal year,” Lyons said.

But it’s been anything but a normal year for the terns, who numbered more than 10,000 pairs in 2008 and has averaged about 9,000 pairs since 2000 at East Sand. The entire Columbia River estuary Caspian tern colony settled on East Sand in 2000 after being lured there by researchers.

The previous nesting grounds had been upstream at Rice Island. The terns’ favored bare sand nesting area at Rice was covered with vegetation to dissuade breeding, and six acres at East Sand was prepared to the birds’ liking.

The theory, and it has proved out, was that if the terns were moved closer to the ocean they would eat more marine fishes and fewer protected salmon and steelhead. All of the salmon and steelhead from the Columbia-Snake river basin, including 13 listed stocks, swim down through the estuary on their way to the Pacific.

Soon after the terns began laying eggs, a two-pronged attack began in mid-May with eagles swooping down to snatch adult terns, which would “flush” the entire colony. When the terns took flight and abandoned their nests, even if briefly, gulls that share the island pounced on the tern eggs.

“Repeated evening/night-time disturbances by bald eagles to the East Sand Island Caspian tern colony occurred, contributing to complete colony failure (i.e., no remaining tern eggs or chicks) on 1 June; thousands of terns are still roosting on East Sand Island and some terns have attempted to re-nest but most tern eggs are depredated by gulls within 30 minutes of laying,” a May 30-June 5 update said.

“…these disturbances and nest predation events coupled with heavy rainfall on 23 May resulting in significant flooding on the colony has caused unprecedented nest failure at the tern colony; the number of active tern nests with eggs has declined from ca. 5,000 to less than 500 over the past two weeks,” according to a research update for the week ending May 29.

Many of those terns kept trying, but the predation continued.

Lyons said that the terns in past years would not all be flushed or spooked off the colony when an eagle flew over during the daytime. But this year’s dusk to early nighttime raids made them extremely flighty. “They cope much better with daytime predators that they can see,” Lyons said.

This year’s tern reproductive failure follows a year when researchers estimated that only 425 fledglings were produced at the East Sand Island tern colony, which held 8,283 nesting pairs at the peak of nesting activity in 2010. The average number of young raised per breeding pair in 2010 was 0.05, which was the lowest productivity recorded in 10 years of study.

“Nesting success at the East Sand Island Caspian tern colony peaked in 2001 and has trended downward since then,” according to the “Research, Monitoring, and Evaluation of Avian Predation on Salmonid Smolts in the Lower and Mid-Columbia River Draft 2010 Annual Report.”“Two factors likely have contributed to declining productivity of the East Sand Island tern colony: ocean conditions and nest predation.”

Two consecutive years of reproductive failure should not hurt the overall population of Caspian terns, Lyons said, because they are very long-lived. The terns have been known to live well over 20 years and start to reproduce at age 4 or 5, so most of the birds will have many more chances.

The researchers are not sure what factors have led to what seems to be an increase in eagle predation, whether it’s related to the food supply or simply changed eagle behavior. With a huge snowpack feeding the Columbia and Snake this year the flows pushing into the Pacific were higher than normal. That likely caused a reduction in the number of marine forage fish that were close at hand as prey for the terns.

“Maybe there wasn’t a lot of food for eagles either,” Lyons said, so they turned to the terns.

The updates are posted at birdresearchnw.org.

Columbia Basin Bulletin

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NOAA initiative to increase of domestic aquaculture output

Friday, July 15, 2011
Posted by: Oregon Water Coalition

During a wet and cool April and May – a time when the Columbia River basin’s water stores usually begin to drain – estimated runoff volumes were boosted by more than 23 million acre feet of water, according to Bonneville Power Administration officials.

Peter Cogswell, Steve Oliver and Rick Pendergrass on Tuesday briefed the Northwest Power and Conservation Council on the current status of the Federal Columbia River Power System and how its dams are being operated to meet power generation, salmon protection, flood control and other demands in what is one of the highest runoff seasons in many years.

Low elevation meltdown has fueled high flows in recent weeks. But mid and high elevation snowpacks across the Columbia-Snake river continued building into the spring season and now hold in excess of 150 to 175 percent of average moisture content. “We expect that to come off here in the next six to eight weeks,” Pendergrass said.

“It is a very unusual occurrence” for the basin to experience such a period of sustained high flows. 2011 flows have been nearly as high as in 1997 when the highest runoff on record flowed down from the Snake and upper Columbia River.

The Northwest River Forecast Center’s June 7 final water supply forecast is for a runoff volume from April through September of 134 million acre feet past The Dalles Dam on the lower Columbia. That would be 136 percent of normal and the fourth largest volume on the 41-year record. The highest volume was 140.9 MAF in 1997, followed by 139.7 MAF in 1974 and 134.8 MAF in 1972.

The wet spring resulted in The Dalles forecast being boosted considerably. The April 7 final forecast was for 107 MAF, which would have been 108 percent of the 30-year average runoff during the April-September period.The Snake River basin is particularly laden. The new NWRFC forecast predicts 37.3 MAF will flush down from the upper Snake and past Lower Granite dam in southeast Washington. That would be 155 percent of average for the April-September period. Lower Granite is the fourth dam upstream from the Snake’s confluence with the Columbia.

The reservoir backed up by Dworshak Dam in west-central Idaho is expected to receive 142 percent of its average inflows. Dworshak is on the North Fork of the Clearwater, which feeds into the Clearwater and then the Snake upstream of Lower Granite. Grand Coulee Dam inflows are predicted to total 80.4 MAF this year, which would be 126 percent of average.The high flows so far have forced dam operators to spill even more water to provide passage for juvenile salmon and steelhead headed for the ocean. Bonneville has since May 18 been forced to implement its new “environmental redispatch policy” for parts of all but two days.

The policy calls on non-hydro energy flowing into the transmission grid, including fossil-fuel and other thermal generation and wind energy, to be partially and temporarily limited so that hydro production can be maximized during low power demand periods. Running more water through the turbines reduces the volume that has to be spilled. Spill stirs up “total dissolved gas,” which can be harmful to fish.

A total of 59,313 megawatt hours of energy had been displaced as a result of the redispatches, Pendergrass said. With an uptick in Snake River runoff, much of the responsibility for holding down flows past Bonneville Dam has been shifted to the mid-Columbia’s Grand Coulee Dam in central Washington.

Columbia Basin Bulletin

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2011 now fourth largest runoff in 41 years

Friday, June 10, 2011
Posted by: Oregon Water Coalition

During a wet and cool April and May – a time when the Columbia River basin’s water stores usually begin to drain – estimated runoff volumes were boosted by more than 23 million acre feet of water, according to Bonneville Power Administration officials.

Peter Cogswell, Steve Oliver and Rick Pendergrass on Tuesday briefed the Northwest Power and Conservation Council on the current status of the Federal Columbia River Power System and how its dams are being operated to meet power generation, salmon protection, flood control and other demands in what is one of the highest runoff seasons in many years.

Low elevation meltdown has fueled high flows in recent weeks. But mid and high elevation snowpacks across the Columbia-Snake river continued building well into the spring season and now hold in excess of 150 to 175 percent of average moisture content. “We expect that to come off here in the next six to eight weeks,” Pendergrass said.

“It is a very unusual occurrence” for the basin to experience such a period of sustained high flows. 2011 flows have been nearly as high as in 1997 when the highest runoff on record flowed down from the Snake and upper Columbia River.

The Northwest River Forecast Center’s June 7 final water supply forecast is for a runoff volume from April through September of 134 million acre feet past The Dalles Dam on the lower Columbia. That would be 136 percent of normal and the fourth largest volume on the 41-year record. The highest volume was 140.9 MAF in 1997, followed by 139.7 MAF in 1974 and 134.8 MAF in 1972.

The wet spring resulted in The Dalles forecast being boosted considerably. The April 7 final forecast was for 107 MAF, which would have been 108 percent of the 30-year average runoff during the April-September period.The Snake River basin is particularly laden. The new NWRFC forecast predicts 37.3 MAF will flush down from the upper Snake and past Lower Granite dam in southeast Washington. That would be 155 percent of average for the April-September period. Lower Granite is the fourth dam upstream from the Snake’s confluence with the Columbia.

The reservoir backed up by Dworshak Dam in west-central Idaho is expected to receive 142 percent of its average inflows. Dworshak is on the North Fork of the Clearwater, which feeds into the Clearwater and then the Snake upstream of Lower Granite.

Grand Coulee Dam inflows are predicted to total 80.4 MAF this year, which would be 126 percent of average.The high flows so far have forced dam operators to spill even more water to provide passage for juvenile salmon and steelhead headed for the ocean.

Bonneville has since May 18 been forced to implement its new “environmental redispatch policy” for parts of all but two days.

The policy calls on non-hydro energy flowing into the transmission grid, including fossil-fuel and other thermal generation and wind energy, to be partially and temporarily limited so that hydro production can be maximized during low power demand periods. Running more water through the turbines reduces the volume that has to be spilled. Spill stirs up “total dissolved gas,” which can be harmful to fish.

A total of 59,313 megawatt hours of energy had been displaced as a result of the redispatches, Pendergrass said.

With an uptick in Snake River runoff, much of the responsibility for holding down flows past Bonneville Dam has been shifted to the mid-Columbia’s Grand Coulee Dam in central Washington.

Columbia Basin Bulletin

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