The challenges of maintaining wild trout in a “working river”

My co-workers keep reminding me that I need to post a blog once in a while, and those of you who know me well know that my lack of blogging activity has nothing to do with lack of something to say.  Every day in the course of my work I come across ideas and information that I think would make great blog posts, but every day, more things end up in the “in” box than the “out” box, pushing blogging farther down the priority list. 

The last two weeks have been more hectic than usual, resulting in an “out-minus-in” deficit even greater than average.  However, my work over the past two weeks provides an excellent example of the challenges we face in maintaining wild trout fisheries in the Henry’s Fork.  I thought sharing these challenges with you would make a great blog post and give some deeper insight into HFF and its work.  As with most things I write, it’s a little long, but look at this way—it’s five or six weeks’ worth of shorter blogs! 

The Henry’s Fork is nothing short of one of the greatest trout streams in the world.  Tens of thousands of people come to our area each year specifically to fish for wild trout on the Henry’s Fork and its tributaries. Thousands of others choose to live in eastern Idaho because of the great trout fishing, and for most of us, the Henry’s Fork is the centerpiece of that fishing.  The subtitle of Mike Lawson’s recent guide book to fishing the river describes it as “…80 miles of world-class water.”  Anyone reading this blog already knows why this description is accurate.  Anglers come here expecting the Henry’s Fork to provide a world-class fishing experience.

However, what is less well understood by anglers is just how many other people expect the Henry’s Fork to provide goods and services that are not necessarily compatible with wild trout.    The Snake River has long been described as a “working river,” and the Henry’s Fork is an integral part of the complex system of surface- and groundwater that sustains most of the economic activity in the State of Idaho.  Indeed, the Henry’s Fork itself is a “working river.”

Flow in the Henry’s Fork is regulated almost from the beginning of the watershed, at Henry’s Lake Dam.  By the time the river has reached the Teton River confluence, it has flowed through two more reservoirs, through four hydroelectric power plants, under a dozen bridges, and over nine irrigation diversion structures.  If you count its major tributaries upstream of that point—the Buffalo, Warm and Fall rivers—add another irrigation storage reservoir, two more power plants, another dozen bridges, and nine more diversions.  And this doesn’t even count the Teton River, which is another story on its own. 

During late summer, the total amount of water diverted from the Henry’s Fork between Chester and the Teton River can often exceed the amount of the river’s flow at Chester.  This occurs because some of the water that is diverted into irrigation canals seeps back into the river, where it is diverted again.  Much of the water that sustains the fishery downstream of St. Anthony has not only flowed through reservoirs and power plants to get there, it has also flowed through irrigation canals, ditches, pumps and sprinklers, only to find its way back through the soil and aquifer to the river.  Now that’s a hard-working river! 

Keep in mind that the irrigation infrastructure I mention here was built prior to 1940.  Three of the power plants date back at least that far.  The vast majority of irrigation water rights in the watershed were claimed prior to 1940.  The working river pre-dates “wild trout fishing regulations” and HFF by several decades. 

Now, irrigation and hydroelectric generation are not inherently “bad”; they simply reflect our society’s demand for goods and services—agricultural products and electricity in this particular case—and past and current government policies set to promote production of these goods and services. But they can certainly cause less-than-optimal conditions for wild trout.  Altered streamflow regimes, sedimentation, fish migration barriers, and fish entrainment can all be incidental by-products of these activities and of other routine aspects of modern society such as building and maintaining roads and bridges.  When you look at the river in that light, it is a wonder that there are any trout in it at all, let alone wild trout—let alone wild trout that support a world-class fishery.

Our job at HFF is to conserve and protect the wild trout fisheries of the Henry’s Fork.  Our members have entrusted us with this job, and it is truly an honor and privilege to accept that trust.  But, the job also carries with it a lot of responsibility and expectations.  After all, this isn’t just any river or any trout we’re talking about—it’s the Henry’s Fork.  The river’s reputation alone puts a lot of pressure on us; our work has to live up to the reputation of the river.  Hard enough to do on any 80-mile section of river, but especially hard in 80 miles of river that society expects to provide irrigation water to 250,000 acres of crop land, generate electricity, provide boating and other recreational opportunities, AND support a world-class trout fishery.

And so when something goes wrong, as it inevitably does, I feel a sense of personal failure.  On the afternoon of October 23, I received a call from Mike Lawson, who was fishing with clients on the Henry’s Fork near St. Anthony.  The river was dropping rapidly, small trout were becoming stranded, and brown trout redds were being exposed.  Flow dropped from 1050 cfs to 620 cfs in an hour. 

However, I was not in the office to take Mike’s call—I was at a meeting of the Water Resources Planning Committee of the Idaho Water Resource Board.  I was there to deliver HFF’s comments on a stream channel alteration permit application for a private fishery enhancement project on Fall River.  This issue is a long story in its own right, but the bottom line was that the landowner’s agent had requested that the Board amend the Henry’s Fork Basin Plan to allow alteration of the channel in a reach of river in which such activities are prohibited.  Back in the early 1990s, when it was a volunteer organization run by Mick Mickelson and a few others, HFF worked hard to achieve the protections that were eventually passed by the legislature in the Basin Plan.  At the Water Resource Board meeting, not only was the integrity of an unaltered reach of Fall River at stake, but the protections of the Basin Plan were also potentially at stake.  This issue is not completely settled, but HFF’s presence at that hearing was absolutely critical.  Without my attendance, the river would not have had a voice that day with the Water Resource Board, which has the ultimate authority for managing Idaho’s rivers.

Meanwhile, back in the river at St. Anthony, flows fortunately rebounded to 1080 cfs within 45 minutes.  Although there was probably some mortality among small fish, the incident did not last long enough for water to drain from the gravel in redds, and therefore it probably did not affect any newly laid trout eggs.  The groundwater inputs I mentioned above helped reduce the effects of the flow reduction with distance downstream; at Rexburg, the event produced only a 70-cfs drop in flow, spread out over a 7-hour period.  The greatest effects were concentrated in the reach between Chester and the Independent Canal diversion.  But, the flow disruption was a stark reminder of what can happen in a working river. 

While talking with Mike about the incident, it became clear that both of us were less concerned about the short-term ecological effects of this one incident than about the potential long-term effects of all of the dams, diversions, power plants, roads, and bridges combined, not to mention additional effects from recreation, which still includes a six-fish harvest limit downstream of Del Rio Bridge.  Mike was also concerned about HFF’s ability to anticipate and prevent such incidents in the future, particularly on the lower river.  On my end, I felt a sense of failure that this happened “on my watch”; maybe I wasn’t paying enough attention to flow issues on the lower river. But it forced me to think about the challenges we face and ask myself, “does HFF have the ability to meet these challenges?”

To answer that question, I looked at my daily planner and my to-do list—going back just to the beginning of the week of the flow incident.  On Monday, I sent one of our field technicians out first thing to collect water samples as part of our regular monitoring program.  I then spent most of the rest of the day analyzing water-quality data and preparing a presentation on the findings to present at the Henry’s Fork Watershed Council the following day.  That preparation was interrupted by a conference call involving Trout Unlimited, Idaho Department of Fish and Game, and Dr. John Loomis at Colorado State University.  The topic of the call was planning for Dr. Loomis to repeat his 2004 study of the economic value of angling on the Henry’s Fork and South Fork.  We need updated information on the value of angling to our local economy to give wild trout and the water they need a seat at the table when water-management decisions and policies are set.  On Tuesday morning, I was in the office at 7 a.m. to prepare the water samples for shipping to the lab before heading to the Watershed Council meeting with Brandon.  We went directly from the Watershed Council meeting to the weekly luncheon meeting of the St. Anthony Rotary Club, where Brandon and I tag-teamed a presentation on HFF and its projects. 

Nearly the entire day on Wednesday was spent carefully reviewing the information on the Fall River fishery enhancement project and crafting the comments I would deliver to the Water Resource Board on Thursday.  I took an hour out of that process to participate in a conference call with Idaho Fish and Game regarding its protests of several new water-rights applications to withdraw water for aquifer recharge.  I spent more time on this Thursday, before heading to the Water Resource Board meeting, where, after delivering HFF’s formal comments on the Fall River stream alteration permit, I made a statement to the Board regarding its second item of business that day—aquifer recharge and stabilization.  On Friday morning, while I was beginning to investigate the St. Anthony flow issue, Fall River Electric engineer Dave Peterson stopped by to let us know that they needed to increase flow at Island Park Dam from about 200 cfs to 480 cfs for a few minutes to recalibrate a sensor.  We asked him to conduct the flow change at night, to avoid potential danger to anglers who might be fishing downstream.  He agreed, and the adjustment was done at 10 p.m.  In the afternoon, I went to Pocatello to deliver an invited presentation to the mathematics department on some methods I have developed in the analysis of time series data—the same methods I use on a routine basis in my work at HFF in analyzing streamflow and water-quality data. 

I spent nearly the entire day on Monday of this week investigating the St. Anthony flow incident.  From the USGS streamflow records it was clear that the flow disruption occurred downstream of the Fall River confluence but upstream of St. Anthony.  Most of the irrigation canals in the reach were not diverting any water, and the adjustments at the remaining canals could not account for a 500-cfs drop in flow.  Chester Dam was the only possible source of the disruption.  My colleague, Anne Marie Emery, happened to be at Chester Dam on Thursday afternoon to check the fish ladder and adjust the underwater camera we use to monitor fish passage.  The rubber dam had been deflated to lower the forebay (what we call the “backwater”) level to facilitate power-plant maintenance work.  The plant operators began inflating the dam again at around 2 p.m., just before Mike noticed the drop in flow a few miles downstream.  From the USGS gage data, I estimated that about 35 acre-feet of water were stored during the flow incident.  Engineering curves I uncovered in my investigation process showed that at current river flows, the backwater has a surface area of around 35 acres.  The rubber dam inflation process increased the backwater elevation around one foot.  Applying a one-foot depth increase to a reservoir of 35 acres is 35 acre-feet of storage—pretty clear evidence that the rubber dam refill had caused the flow disruption. 

After talking with Mike, former HFF Board members who were involved in the original Chester hydroelectric project negotiations, Fall River Electric’s engineer and the power plant operator, it was apparent that nobody had thought of the possibility that the relatively benign operation of lowering and raising the rubber dam could have such a dramatic effect on river flow.  The power plant operator told Anne Marie and me that he deliberately filled the rubber dam slowly, using manual operation, to raise the water level gradually and avoid dewatering the river downstream.  In retrospect, we all learned a lesson about how a relatively small operation, performed in a well-intended manner, could affect river flow.  The disruption would have barely been noticed had it occurred in the spring or summer, when river flow is 2000 cfs or greater, but when flow is around 1100 cfs, just barely enough to keep side channels watered, a 500 cfs drop makes a big difference.

In addition to researching the technical aspects, I dug into the original Federal Energy Regulatory Commission (FERC) license for the plant, the documentation of sale of the license to Fremont-Madison Irrigation District and assignment of the license to Fall River Electric, FERC’s conditions for installation and operation of the rubber dam, the operations plan and other documents.  This background gives us the information we need to work with Fall River Electric, its operator, and relevant agencies to review procedures and develop new ones if needed to prevent incidents like this in the future.

On Tuesday, I spent the entire day modeling water supply at Island Park Dam to have the latest flow information and projections to take to the Drought Management Planning meeting at Fremont-Madison Irrigation District on Wednesday.  All participants agreed to leave Island Park outflow at 180 cfs until December 1, at which time we will raise the flow to 270 cfs for the benefit of trout survival, with the understanding that we may have to cut flow by about 30% in March, after the coldest part of winter is over, if water supply is insufficient at that time to fill the reservoir.  The subject of aquifer recharge came up again at that meeting.  I went directly from that meeting to Chester Dam, where I discussed the flow incident with power plant personnel and got an inside view of the plant’s control and data-recording instruments.

Thursday was spent getting information about the flow incident out to our members, analyzing data related to aquifer recharge water rights, and thinking about what to write in this blog, which brings me back to my original question: “What are the challenges of maintaining wild trout in a working river, and is HFF up to the task?”

The existing challenges are clear: just look at the number of dams, diversions, power plants, and bridges I list above.  As you know, we’ve got two bridges under replacement right now—Del Rio and Stone bridges—and Ora is next on the list.  A little blip or small incident at any one of these facilities or construction sites has the potential to put a small amount of sediment in the river or disrupt flow.  On its own, any one incident wouldn’t cause much harm, but the cumulative effects can be much greater in the long run.  And of course, if several “little” blips occurred at different locations all at the same time, the resulting effect could be substantial. 

Up in the Caldera reach, things are pretty straight-forward: pay attention to water management at Island Park Dam, monitor water-quality in several locations above and below the reservoir, manage fish passage at the Buffalo River, and maintain the fences at Last Chance and Pinehaven to prevent cattle damage to the streambanks.  Although we’re not perfect, I think we do a great job with these tasks.  Anne Marie has been tirelessly carrying the load on Buffalo River fish passage project, fence maintenance, and monitoring of our projects in Island Park.  Our interns and part-time technicians have assisted in these duties, in addition to collecting water samples and keeping our water-quality instruments functioning.  Our collaboration with Fremont-Madison Irrigation District, Fall River Electric, and government agencies has greatly improved water management at Island Park Dam.

But, things are much more complicated on the lower river, where river conditions reflect management of every dam, diversion, power plant, and construction site upstream—not just Island Park Dam.  We definitely have our work cut out for us to address flow fluctuation issues at both Ashton Dam and Chester Dam.  Furthermore, we are faced with proposals to increase the amount of water stored in Island Park Reservoir by 20% and to divert another 2000 cfs or so from the lower Henry’s Fork for aquifer recharge (notice how this keeps coming up?).  If these proposals come to pass, our constraints for managing the river for wild trout become even tighter.   

Fortunately, we are positioned to address these issues on a number of fronts.  We continue to maintain and strengthen relationships with Fall River Electric, Rocky Mountain Power, water users, and water managers.  During 2015, we will expand our water-quality network into the lower river.  This will give us the scientific information we need to clearly identify problems and suggest workable solutions.  Finally, we are intimately involved in both the technical and administrative aspects of long-term water management at all levels—from the Island Park Reservoir expansion proposal all the way up to state-wide plans for aquifer recharge.  In every case, we are recognized as a source of objective, high-quality scientific information and a respected voice of reason in balancing the needs of the fishery with the needs of other activities that are critical the economic stability and viability of Idaho.  Instead of sitting on the sidelines saying “they want to expand Island Park Reservoir” or “they want to divert more water from the river” and then submitting comments through a public hearing process after the plans are already drawn, we are at the table throughout the whole process, shaping the plans and proposals and including fish and wildlife considerations from the beginning, not as an add-on at the end.

This is HFF’s time-tested and signature approach—bring solid data and information to the table, be proactive, and work with the other river stakeholders rather than against them.  There are times when our patience is tried, when it would be easier to be confrontational, and when we think we have moral and/or legal “high ground” to draw lines in the sand.  But every time we get to that point, we take a step back, look at our mission statement and strategic plan, and, quite honestly, “get real!”  HFF does not own land, and we do not hold water rights.  Idaho water law was written primarily to allocate water for irrigation and secondarily to allow full development of water resources for hydroelectric power generation and other uses.  This is reality, and it requires us to work collaboratively rather than confrontationally and to bring the best scientific and technical information to the table.  Our mission and strategic plan clearly state this, and they reflect the collective wisdom and guidance of current and past members of the HFF Board of Directors.  With this guidance and wisdom, HFF is, in fact, capable of maintaining wild trout in the Henry’s Fork.  The river is being asked to work harder, and we will meet the challenge by working just that much harder to protect it.