Up-River Summary. By Terry Gunn
Like they used to say on the radio: There’s good news and bad news. What a difference a year can make.
The good news. The river is healthier than it has been in many years. There is more algae than anyone can remember; a solid mass of green, from bank to bank and throughout the entire river. There has been so much algae that it has made spin fishing virtually impossible – every cast the line is almost instantly clogged with a gob of algae. This algae bloom is likely a result of Lake Powell being stirred up last year by the large spring runoff which resulted in nutrients being distributed in the reservoir and now are being transported into the river. Algae and the diatoms that it harbors are the foundation for the aquatic food base at Lees Ferry. We had large hatches of black flies which we had not seen in a few years for most of this past winter. The midges began hatching in earnest in early March and these massive hatches have continued on a daily basis. The fish look great and I feel that – with the current health of the river – we are going to see some great fishing in the future.
Last year at this time the river was full of healthy fish of all sizes. This year, we still have a decent population of trout, but everything has changed, including where they are living in the river and where and what flies they are eating. The guides are all catching fish while DIY anglers are struggling. Fish that normally are in the shallow water feeding on the prolific midge hatches are all in the deeper water, feeding on the midge pupae. It took us awhile to figure out that to catch fish we needed to get much deeper than normal. On the weekends, the water is lower and an angler can have some success in the shallower water, but for the most part we have not been wading; instead, we are fishing from the boat, either drifting or anchoring. We have been using much smaller flies than normal because the fish have been more selective and very picky. Our best success has been using a 12- to 14-foot leader with a strike indicator near the fly line. Couple that with a #4 or BB spilt shot 18-inches above a size-18 bead-head zebra midge with a size-20 zebra bead head (or smaller) underneath. If you’re using different patterns or larger flies, you are not going to have much success.
Fishing is changing daily. It is our goal and desire that everyone have a great trip to the Ferry. Be sure to stop by the shop to see the flies that are currently working. The flies change on a daily basis and every day the LFA guides let everyone at the shop know the top producing flies and how to use them and we are anxious to share this knowledge with you, even where to fish.
Just because you caught fish in a certain spot in years past, don’t think that you are going to experience the same success in the same spot this year. You might remember that this fishery has changed many times over the years and this year is one of those big change years. Keep in mind that the fish are in the deeper water. The other thing to remember is that the section of river above 7 mile is fishing better than the lower river. We lost a lot of fish this past winter in certain areas. Those most impacted are the walk-in, 4 mile, and Duck Island. There are not many fish in these regions and it is going to take some time for fish to relocate back. In a nutshell, it was warm water, extreme low flows and an artificial flood that came together that changed our fishery. Read on for a more detailed explanation of how that change occurred.
It all began last summer when there was a very large runoff into Lake Powell which at that time was less than 50% of capacity. I believe that the large runoff mixed up the normally stratified water in the lake and a result, the water that entered the river gradually increased in temperature and eventually went up to 58 degrees, which has happened other years in the past without negative consequences; this time, however, radical water flows were injected into the mix.
As you likely know, for the past three Novembers there have been HFE’s or artificial floods to allegedly rebuild the beaches in the Grand Canyon. I and many others have been opposed to these fall floods on many fronts, questioning their effectiveness and most importantly, timing. Fall is not a natural time of year for a flood event to occur. We have said all along that these floods can have a negative effect on the trout and the aquatic food base of the river … just as the canyon is going into winter. Winter on this stretch of river means that due to the low trajectory of the sun and our high cliffs, very little to no sunlight enters the canyon and strikes the river. It can be a long, tough winter even in normal conditions. Throw a flood into the mix and it can spell disaster.
However, this year was anything but normal. When they conduct one of these flood events, Lake Powell drops more than three feet in 70 hours. In years past, they have taken a little bit of water from the water delivery every day, throughout the year to save enough water to do one of these HFE flows. This year, some nameless bureaucrat or group of them, decided to break protocol and basically stole all the water from November to conduct this flood. In other words, for the entire month of November, the river flows fluctuated from a low flow of 6,500 cfs to 7,500 cfs on a daily basis (with the exception of the 70 hour 38,000 cfs flood event). Normal flows for these months would be 8,000 cfs to 13,000 cfs. Back in 2000, they conducted another low flow experiment (8,000 cfs constant flows, June-October), that was highly detrimental to the fishery and aquatic food base. We all thought that at that time that it was agreed that the river would not drop below 8,000 cfs and low and steady flows would be avoided if at all possible. Obviously somebody was not paying attention or did not care about the Lees Ferry trout fishery.
The condition of the fish entered into a gradual decline in late October … this happens most every year as food production declines. Everything was fine until the abnormally low flows began in November. We instantly saw a very rapid decline in fish health and condition and for reasons that I cannot explain some areas of the river the fish were hit harder than other areas. I’m convinced that it was a combination of the radically low flows, warmer than normal water followed by the flood that caused this rapid decline. The fishery would have likely escaped unscathed if it had only been a combination of two of these events, but all three combined to create the perfect storm that will temporarily change this fishery.
Has the fishery changed? Yes, as it has many times in the past. Is Lees Ferry done for? No, it has always returned to normal after a short down-turn. What can you do to help? We all need to become involved and write letters and attend meetings and let government officials know that Lees Ferry is a special place and that recreational fishing should be enhanced and protected from harmful water flow experiments.
There has been an ongoing aquatic food base study that has taken place over the past couple of years. The purpose of this study is multifaceted and is studying the relationship of flows on food production, taking inventories of and monitoring populations of aquatic insects and invertebrates that live in the river and other very important aspects of the aquatic food base. I believe that this is by far the most important study that has ever been conducted on this river. Previously, hundreds of millions of dollars have been spent studying sediment while ignoring the aquatic food base and resource. Common sense dictates that fish, birds and animals do not live off of dirt or sand. The aquatic food base and habitat are the foundation for all that lives in the Colorado River. One of the long term goals of the food base study is to determine how to enhance the populations and production of aquatic insects in the river which will benefit native fish, trout, and migratory bird populations. This is a study and a goal that we can all embrace!
There is currently an El Nino occurring and unfortunately, it appeared too late to bring us any drought relief. However, there is a 65% chance that there will be an El Nino event that carries over through the summer and into next fall and winter. Strong El Ninos almost always bring big snow packs to the Rockies which could help to fill both Lake Powell and Lake Mead. Current snowpack in the Lake Powell drainage in only 55% of normal and we desperately need more snow this late spring to bring the lake up.
Quagga mussels have become established in Lake Powell and we are now seeing some in the river below the dam. Their arrival in the river happened sooner than I expected. So far, there has not been a major infestation and there is some thought by experts that they will not become very well established in the river due to the current. Be aware and remember to dry waders and boots before using them in any other body of water. Also, all private boats should drain all water from the boat and live-wells as soon as you exit the river. We all need to do our part to limit the transport of this and all invasive species.
We are hearing a few more positive reports on the walk-in area, but it is still very slow compared to normal. Perhaps everyone should follow our lead from upriver and fish smaller flies in the deeper runs.
I’ll update this walk-in report as soon as we have more information.
Spin fishing continues to be much slower than normal due to the massive amount of algae that the river is producing. This will be better when the higher flows in June transport much of the algae downriver.
Glen Canyon Dam / Lake Powell
Current Status The unregulated inflow volume to Lake Powell in March was 552 thousand acre-feet (kaf) (83% of average). The release volume from Glen Canyon Dam in March was 649 kaf. The end of March elevation and storage of Lake Powell were 3,591.0 feet (109 feet from full pool) and 10.91 million acre-feet (maf) (45% of full capacity), respectively. The reservoir elevation is near the anticipated seasonal low and will soon begin increasing as spring runoff enters the reservoir.
Current Operations The operating tier for water year 2015 was established in August 2014 as the Upper Elevation Balancing Tier. In the Upper Elevation Balancing Tier the initial water year release volume is 8.23 maf; however, there is the possibility for an April adjustment to equalization or balancing operations to govern for the remainder of the water year. This April 2015 24-Month Study establishes that Lake Powell operations will shift to “balancing releases” for the remainder of water year 2015. Under Balancing, the contents of Lake Powell and Lake Mead will be balanced by the end of the water year, but not more than 9.0 maf and not less than 8.23 maf shall be released from Lake Powell. Based on the most probable inflow forecast, this April 24-Month Study projects a balancing release of 9.0 maf in water year 2015; the actual release in water year 2015, however, will depend on hydrology in the remainder of water year and will range from 8.23 to 9.0 maf. The projected release from Lake Powell in water year 2015 will be updated each month throughout the remainder of the water year. Reclamation will schedule operations at Glen Canyon Dam to achieve as practicably as possible the appropriate total annual release volume by September 30, 2015.
In April, the release volume will be approximately 600 kaf, with fluctuations anticipated between about 7,500 cfs in the nighttime to about 13,000 cfs in the daytime and consistent with the Glen Canyon Operating Criteria (Federal Register, Volume 62, No. 41, March 3, 1997). The anticipated release volume for May is 700 kaf with daily fluctuations between approximately 8,500 cfs and 14,500 cfs . The expected release for June is 800 kaf with daily fluctuations between approximately 10,000 cfs and 18,000 cfs.
In addition to daily scheduled fluctuations for power generation, the instantaneous releases from Glen Canyon Dam may also fluctuate to provide 40 MW of system regulation. These instantaneous release adjustments stabilize the electrical generation and transmission system and translate to a range of about 1,200 cfs above or below the hourly scheduled release rate. Under system normal conditions, fluctuations for regulation are typically short lived and generally balance out over the hour with minimal or no noticeable impacts on downstream river flow conditions.
Releases from Glen Canyon Dam can also fluctuate beyond scheduled releases when called upon to respond to unscheduled power outages or power system emergencies. Depending on the severity of the system emergency, the response from Glen Canyon Dam can be significant, within the full range of the operating capacity of the power plant for as long as is necessary to maintain balance in the transmission system. Glen Canyon Dam typically maintains 27 MW (approximately 800 cfs) of generation capacity in reserve in order to respond to a system emergency even when generation rates are already high. System emergencies occur fairly
infrequently and typically require small responses from Glen Canyon Dam. However, these responses can have a noticeable impact on the river downstream of Glen Canyon Dam.
Inflow Forecasts and Model Projections The April to July 2015 water supply forecast for unregulated inflow to Lake Powell, issued on April 2, 2015, by the Colorado Basin River Forecast Center, projects that the most probable (median) unregulated inflow volume will be 3.75 maf (52% of average based on the period 19812010). The forecast decreased by 135 kaf since last month. At this point in the season, there is still uncertainty regarding this year’s water supply and the total inflow to Lake Powell. The spring runoff forecast ranges from a minimum probable of 2.60 maf (36% of average) to a maximum probable of 5.70 maf (80% of average). There is 10% chance that inflows could be higher than the maximum probable and a 10% chance they could be lower than the minimum probable.
As determined in the August 2014 24-Month Study, and documented in the 2015 Annual Operating Plan, Lake Powell’s operations in water year 2015 will be governed by the Upper Elevation Balancing Tier. In this tier, the initial water year release volume is 8.23 maf, however, there is the potential for an April adjustment to equalization or balancing releases in April 2015. This April 2015 24-Month Study projects the end of water year elevation at Lake Powell to be above 3,575 feet and the end of water year elevation at Lake Mead to be below elevation 1,075.0 feet. Therefore, in accordance with Section 6.B.4 of the 2007 Interim Guidelines, Lake Powell operations will shift to “balancing releases” for the remainder of water year 2015. Under Section 6.B.4, the contents of Lake Powell and Lake Mead will be balanced by the end of the water year, but not more than 9.0 maf and not less than 8.23 maf shall be released from Lake Powell.
Based on the April most probable inflow forecast, the annual release volume from Lake Powell during water year 2015 is projected to be 9.0 maf. Under the minimum probable inflow scenario, the water year release is projected to be 8.9 maf. Under the maximum probable inflow scenario, the release is projected to be 9.0 maf. There 10% chance that inflows will be lower than the current minimum probable forecast, potentially resulting in lower releases. If inflows are less than the minimum probable forecast, the water year 2015 annual release could be as low as 8.23 maf. If inflows are greater than the current forecasted maximum probable inflow, the annual release will be 9.0 maf. The projected release from Lake Powell in water year 2015 will be updated each month throughout the remainder of the water year.
Based on the current forecast, the April 24-Month Study projects Lake Powell elevation will end water year 2015 near 3,583 feet with approximately 10.24 maf in storage (42% capacity). Projections of elevation and storage still have significant uncertainty at this point in the season, primarily due to uncertainty regarding spring runoff and the resulting inflow to Lake Powell. Under the minimum probable inflow scenario, updated in April, the projected end of water year elevation and storage are 3574 feet and 9.45 maf (39% capacity), respectively. Under the maximum probable inflow scenario, updated in April, the projected end of water year elevation and storage are 3603 feet and 12.02 maf (49% capacity), respectively. Modeling of projected reservoir operations based on the minimum and maximum scenarios will be updated again in August.
Upper Colorado River Basin Hydrology The Upper Colorado River Basin regularly experiences significant year to year hydrologic variability. During the 15-year period 2000 to 2014, however, the unregulated inflow to Lake Powell, which is a good measure of hydrologic conditions in the Colorado River Basin, was above average in only 3 out of the past 15 years. The period 2000-2014 is the lowest 15-year period since the closure of Glen Canyon Dam in 1963, with an average unregulated inflow of 8.39 maf, or 78% of the 30-year average (1981-2010). (For comparison, the 1981-2010 total water year average is 10.83 maf.) The unregulated inflow during the 2000-2014 period has ranged from a low of 2.64 maf (24% of average) in water year 2002 to a high of 15.97 maf (147% of average) in water year 2011. The water year 2014 unregulated inflow volume to Lake Powell was 10.381 maf (96% of average), which, though still below average, was significantly higher than inflows observed in 2012 and 2013 (45% and 47% of average, respectively). Under the current most probable forecast, total water year 2015 unregulated inflows to Lake Powell is projected to be 7.18 maf (66% of average), and ranges from a minimum probable inflow of 5.9 maf (55%) and maximum probable inflow of 9.4 maf (87%).
At the beginning of water year 2015, total system storage in the Colorado River Basin was 30.0 maf (50% of 59.6 maf total system capacity). This is nearly the same as the total storage at the beginning of water year 2014 which began at 29.9 maf (50% of capacity). Since the beginning of water year 2000, total Colorado Basin storage has experienced year to year increases and decreases in response to wet and dry hydrology, ranging from a high of 94% of capacity at the beginning of 2000 to a low of 50% of capacity at the beginning of water year 2014. One wet year can significantly increase total system reservoir storage, just as persistent dry years can draw down the system storage. Based on current inflow forecasts, the current projected end of water year 2015 total Colorado Basin reservoir storage is approximately 27.4 maf (46% of capacity). The actual end of water year storage may vary from this projection, primarily due to uncertainty regarding this season’s runoff and resulting reservoir inflow. Based on the April minimum and maximum probable inflow forecasts and modeling the range is approximately 26.1 maf (44%) to 29.5 maf (50%), respectively.
Updated April 16, 2015 Katrina Grantz