DRA Releases Reports

On March 4, we posted two new reports under the “Reports” tab on our website.

The first report is the analysis of our 2014 thermal imaging survey of the lower Deschutes River.

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This report is the analysis of the first known thermal imaging look at mid-summer temperature behavior in the lower river.  There were many unanticipated surprises from the imaging, but two findings are of greatest importance.

  • The thermal behavior of water discharged from the Pelton-Round Butte Complex during nighttime hours is unaffected by “canyon effect.” Canyon effect warms the water during the day as a product of solar radiation exposure.  Nighttime discharge, however, avoids much of the daytime warming effect.   Yet all temperature calculations used for temperature management by dam operations act as if water temperature and temperature behavior are the same day and night.  It has also been stated by the dam operators that “cooler temperature discharge from the dams wouldn’t make any difference” because of “canyon effect.”  Our findings contradict that.
  • Solar radiation (down-bound long wave radiation) is far more important than air temperature in determining river temperatures. Solar radiation warms both air and the water in the river.  That means that shade from canyon walls and riparian vegetation is important in maintaining cooler water in the river.  Air temperature in Redmond is also an important factor in determining the goal for temperature management for dam discharge, yet air temperature has little effect on water temperature.

The second report describes our data and findings from the 2015 water quality study we did in Lake Billy Chinook and in the lower river just below the Pelton-Round Butte Dam Complex. 

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The Selective Water Withdrawal Tower at Round Butte Dam (the uppermost dam of the three dam complex at Pelton-Round Butte) has intake portals in the top 30 feet of the reservoir, and at 265 feet of depth.  To better understand the water quality effects of Tower operations and selective water withdrawal, we sampled surface water and water at depth in front of the Tower, as well as in the river below the dams.

The data we gathered demonstrated many things, and also raised more questions that we will be attempting to answer through the water quality sampling we started in February of this year. Our results from 2015 shed light on a number of critical factors, including that:

  • Surface water withdrawn from Lake Billy Chinook, for much of the year, consists primarily of water from the Crooked River Arm of the reservoir.
  • Water from the Crooked River Arm is warmer, and of poor water quality (the Crooked River water quality above the reservoir is rated as “poor” by Oregon Department of Environmental Quality). Plus, the water in the Crooked River Arm supports the densest level of algae growth in the reservoir.  In contrast, water from the Metolius River, which, because of its colder temperature constitutes most of the water at the depth of 265’, is of high quality (based on ODEQ data, as well as our own data).

Questions we are hoping to answer in 2016 include (but are not limited to):

  • What is the “nutrient load” entering Lake Billy Chinook from the three tributaries, and when does it get discharged from the dam complex into the lower Deschutes River? Algae in the upper water of the reservoir actually help decrease nutrient levels during summertime growth, but nutrients in surface water discharged in late fall, early winter and spring are not likely attenuated by that algae, and probably contributes significantly to the growth of nuisance algae that has been documented in the lower river.  So we are now tracking nutrient levels at the surface and at depth in the reservoir and below the dams.
  • Is the surface water in the Crooked River Arm of Lake Billy Chinook too toxic for migratory juvenile fish survival during major algae blooms due to high pH, high temperature and/or other variables?
  • Is operation of the dam complex in compliance with the water quality requirements of the Pelton-Round Butte Section 401 Certification under the Clean Water Act and the Federal Energy Regulatory Commission license?

We would also like to announce that we are (finally!) getting some of our raw water quality data posted on our website.  We are open-sourcing the data for all to view or use.  It will take some time to get everything posted, but we will be working on this going forward.

We hope to post updates on our work throughout the year.  So please stay tuned.

Deep and heartfelt thanks to our donors and supporters for making this work possible!

Deschutes River Alliance: Cooler, cleaner H2O for the lower Deschutes River. 

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The Low Down on High Temperatures in the Lower Deschutes River

by Greg McMillan & the Board of Directors of the Deschutes River Alliance

Lower Deschutes River. Photo by Robert Sheley.

Lower Deschutes River. Photo by Robert Sheley.

Introduction

It’s been a rough summer.  No one anticipated the fish die offs and warm water temperatures to the degree we experienced in June and July.

Fortunately, we dodged the bullet with a second heat wave.  It was of short duration, and then broken by cooler temperatures, cloud cover and some rain.

But it was long enough to see a trend emerge regarding temperature management at the Pelton-Round Butte Dam Complex.  The dam operators were already warming up discharge temperatures, and warming the lower river, until we got a break from the heat.  They were once again artificially raising the temperature of the lower river in the face of already naturally warming temperatures.  Here’s what it looked like (these temperatures are from the Pelton Reregulation Dam tailrace):

Water temperatures at Madras gage, July 27 - August 3, 2015. Source: USGS online.

Water temperatures at Madras gage, July 27 – August 3, 2015. Source: USGS online.

During the same time frame, here is what was happening down at the mouth of the Deschutes River:

Water temperatures at Moody gage, July 27 - August 3, 2015. Source: USGS online.

Water temperatures at Moody gage, July 27 – August 3, 2015. Source: USGS online.

Observations

There are several observations to be made here:

  • As the weather warmed, so did the temperature at the Pelton Reregulation Dam tailrace. This is in accordance with Portland General Electric/Confederated Tribes of the Warm Springs Reservation “Without Project Temperature” calculation that is based on a mathematical model.  The WPT calculation estimates (or models) what the water temperature would be if the dams were not present.  WPT is then achieved by  mixing bottom and surface water at the Selective Water Withdrawal Tower at Round Butte Dam, before it is passed downstream to Pelton Dam and the Reregulation Dam.  Here is the equation:

Water Temperature Pelton = 2.8+(0.79)(Water Temperature into LBC)+(0.071)(7-day Ave Air Temperature Redmond Airport)

  • This PGE model uses the water temperatures of the tributaries (Metolius, Middle Deschutes and Crooked Rivers) entering Lake Billy Chinook, along with air temperature at Redmond airport, to derive the calculated target temperature (WPT) for dam discharge.
  • The lower river, running for 100 miles below the dams, has a daily swing of nearly six degrees during the summer. The tributaries above Lake Billy Chinook have a similar swing in daily temperatures, varying by up to six degrees between morning and late afternoon temperatures.
  • The discharge temperature at the dam complex only varies about 1 to 1 ½ degrees daily.
  • The temperature discharged from the Reregulation Dam tailrace has a major influence on lower Deschutes River water temperatures.
  • The temperature management model warms the lower Deschutes River in spring and summer, but cools it in the fall. Based on annual temperature curves, the spring/summer warming is much greater than the cooling in the fall.  Therefore, the lower Deschutes is experiencing net warming during a year-long cycle.
  • The temperature model for the dams increases temperature in the lower Deschutes when the lower river is already warm (at times too warm) in spring and summer.

It should be noted that the stated goal of temperature management using the Selective Water Withdrawal Tower is to “eliminate the thermal presence” of the Pelton-Round Butte Complex.

These observations made us curious.  How can you manage water temperature with the goal that the dams would be thermally invisible, and yet not have the daily variances that mimic a natural river?

In trying to figure this out, we also wondered what tributary water temperature is being used to calculate the Without Project Temperature goal?  Is it the average or mean daily temperature?  Is it the minimum daily temperature?  This would be the most beneficial temperature for the biology of the river during heat waves.  Or is it the maximum, warmest temperature of the day?

The Answers

We turned to the Portland General Electric/Confederated Tribes of Warm Springs Reservation annual water quality report that was recently submitted to the Federal Energy Regulatory Commission for the 2014-operating year to try to answer these questions.

It turns out that the tributary temperature used to calculate the Without Project Temperature, and corresponding blend at the Selective Water Withdrawal Tower target for dam discharge, is based on a 7-day average of the peak (warmest or maximum) temperature of each day in the 7-day calculation.  This means that the overnight cooling, and cooler temperatures that prevail throughout most of the day, are ignored.  These cooler temperatures are the temperatures that fish and other organisms rely on to recover from the brief daily period of peak temperatures during summer heat waves, and especially in desert rivers.  It should also be noted that the maximum temperature is only of short duration daily.  But the model acts as if it is the only temperature of the day.

Metolius River water temperatures, Grandview gage, July 19 - July 25, 2015. Source: USGS online.

Metolius River water temperatures, Grandview gage, July 19 – July 25, 2015. Source: USGS online.

The red line in the graph above indicates the temperatures from the tributaries above Lake Billy Chinook used in calculating Without Project Temperature (WPT).

In other words, the dam operators are warming the river during spring and summer well beyond what would be its normal state without the dams because they are artificially managing discharge temperature based on the maximum temperature of the above reservoir tributaries, not the minimum or average daily temperature of the tributaries.

Biological Effects

Charles Huntington, working under contract to PGE, did the seminal work that was done on understanding water temperature behavior in the lower Deschutes.  The work was completed and published in April of 1999.  It became the foundation of how water temperature at the dams would be managed.

In the published results of that study, the impact of temperature changes to the biology of the lower river was only minimally examined.  The most discussion was in regard to changes in the timing of emergence of salmonid alevins from spawning gravel.  The report concludes that juvenile emergence would happen sooner in warmer water conditions.  No impact to the success rate of emergence is noted, or suggested, as a benefit of warmer temperatures.

The question regarding what the impacts and effects on other biota (life forms) is asked, but never answered in the report.  Impacts to resident fish species, aquatic insects, aquatic plant life and algae are not examined.

No mention is made in the report of the role the lower Deschutes plays as a thermal refuge for upstream migrating adult salmonids in the Columbia River when it reaches maximum daytime temperatures during the summer.

No mention is made of what would happen if increasing temperatures, as a result of dam operations, in the lower river during spring and summer, reached the point of causing heat stress in fish.  No defined threshold was set as a maximum river temperature that should be reached before overriding the “mathematical model” to interject human judgment and decision-making.

What is discussed is the role dam discharge temperature plays in affecting temperatures downstream from the dams.  In varying conditions, dam discharge temperature can affect lower river water temperatures as far down as the mouth.  Yet the dam operators are only held responsible for the dam discharge temperature at the Reregulation Dam, not the impacts downstream.

What We Think Should Be Done

It’s time for a reexamination of how water temperature is managed in the lower Deschutes River.   This reexamination should be a more holistic approach to the health of the river and its resident species.

Thresholds should be set where protection of aquatic species is the primary goal for temperature management.

The 2005 dam operating license allows for, and even mandates, adaptive management, meaning changes can be made when new information shows that current methods are flawed. This means PGE, the Tribes, and the agencies responsible for protecting the aquatic health of the river can act now to lower the temperature of water released from the dams.

Dead spring Chinook salmon, July 10, 2015. Cause of death determined to be infection due to heat-related stress. Photo by Andrew Dutterer.

A victim of warm water temperatures. Dead spring Chinook salmon found in lower Deschutes River below Nena boat launch, July 10, 2015.  Photo by Andrew Dutterer.

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The DRA may be in your neighborhood soon!

FFF Booth 2

We don’t just exist on the web!  Dave and I and some of our Board members will be out and about in the upcoming months sharing our findings from meetings with agencies and other stakeholders on the lower Deschutes River.  We’ll also be talking about our scientific investigation plan to figure out how aquatic insect hatches are faring in the lower river, and why we are seeing such a massive proliferation of nuisance algae.  You can find us at the following events on these dates:

Federation of Fly Fishers Expo, March 6 and 7 in Albany, OR  [Thanks to Tom Larimer and Rick Hafele for giving presentations, and thank you to all for coming by the booth!]

Clackamas River Flyfishers, March 18 at the High Rocks Steak House in Gladstone, OR

Deschutes Guides and Outfitters Briefing, March 19, Confluence Fly Shop, Bend, OR

With Damien Nurre, John Hazel and Greg McMillan.

DRA Guides and Outfitters Briefing, April 9, Best Western Hotel, Oregon City, OR

Royal Treatment Fly Shop, Saturday April 26, West Linn, OR

Flyfisher’s Club of Oregon Auction, Tuesday May 13, Portland, OR

Bend Chapter 552 of Trout Unlimited, May 14, Bend, OR

Sandy River Spey Clave, May 16 – 17 – 18, Oxbow Park on the Sandy River

If you have a club or other organization that would like to have us appear in person, please email us and if at all possible, we will accommodate you.

Thanks,

Greg McMillan

DRA_BlogLogo_4.25in

The DRA and the Hatchery vs. Wild Fish Debate

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Clean water is essential to protect the food chain.  Photo by David Moskowitz

The DRA’s position in this debate can be easily summarized.

Quite simply, it’s not the issue we are concerned about right now.

We are trying to protect the lower Deschutes River for all fish:  wild and hatchery spring Chinook, fall Chinook, the resident native red band trout, lamprey, sculpins, and yes, wild and hatchery steelhead.   All of these fish depend on the food chain that starts with aquatic plant life in the lower Deschutes, and that plant life supports the aquatic macroinvertebrates that fish feed on.  Aquatic vegetation and aquatic insects are dependent upon good water quality to support the web of life in the lower river.

March Brown mayfly by David Moskowitz

March Brown mayfly by David Moskowitz

We created the DRA to understand and protect that food chain, and the water quality it depends upon.

Some from outside of our organization have the perception that we are only affiliated with organizations that promote and protect wild fish.  The DRA is not a part of any other organization; we are an independent conservation organization.  Like with all conservation groups, the DRA has members and advisers that belong to other groups.  We did not discriminate against anyone because of their affiliations, nor shall we.  Rather we accepted their voluntary membership based on their desire to protect the lower Deschutes and the expertise that they brought with them.  We have a highly qualified and experienced panel of science advisors, and we have a Board of Directors that is uniquely qualified to lead our organization.  It is those qualifications that led to membership in our organization, not organizational affiliations.

Anyone who has spent time on the lower Deschutes River in the past three years knows that there are major changes happening.  Aquatic insect hatch timing has changed, some hatches have for all practical purposes disappeared, and then there is the recent proliferation of potentially harmful algae.

Excessive algae growth -Summer 2013

Excessive algae growth -Summer 2013 – Photo by Greg McMillan

These are the problems we are focused on, and it is those problems we aim to solve.  Please look for our 2014 Science Plan to see what our focus is.  We are doing this for the benefit of all Deschutes River fish and the benefit of all anglers.

Sincerely,

Greg McMillan

President of the DRA Board of Directors