Just a quick update and a full report will follow in a few days. The cicadas are singing. They are later than normal by a week or so which is likely due to much cooler weather than normal for the first 2 weeks of June. That has certainly changed though…we have been much warmer than normal for the last 2 weeks. I’m not sure how big the hatch is going to be but we are hearing more bugs sing every day. If it were to stay the same as it was today I would call it a light hatch cicada hatch but that could likely change. It is too early to have any fish really keying in on cicadas but that will change as the hatch matures and more bugs get on the water. The water goes up on July 1 to 14 to 22,000-cfs and again on July 14, 16 to 24,000-cfs. This is much higher water than we have seen in several years because of trying to balance Lake Mead.
June 1 2015
By Terry Gunn
I have lots of good news to report. The fishing has continued to improve significantly. The fish are in better shape than we have seen in a very long time. All of the guides agree that we have never seen the fish growing as quickly as they have the last couple of months. The river is healthier than it has been in many years. There is more algae than anyone can remember; a solid mass of green covering the bottom of the river, from bank to bank and throughout the entire river. This algae is the foundation for the aquatic food base and hosts the diatoms that provides the food for all the aquatic organisms. More algae is a great thing. This algae crop is likely a result of Lake Powell being stirred up last year by the large spring runoff, resulting in nutrients being distributed in the reservoir and now are being transported into the river. We have had large hatches of black flies for most of this past winter which we had not seen for a number of years. The midges began hatching in earnest in early March and these massive hatches have continued on a daily basis.
The fish are in perfect condition and I think that by the end of this summer we are going to have a much larger average size trout than we have seen in many years. Most all of our customers have recently been commenting on the fact that the fish that we are currently catching are on average larger than in previous years … and they are growing fast. We are going to have higher than normal flows this summer. In years past, high flows have resulted in very rapid growth rates and big fish due to the fact that high water moves the large food items (scuds and worms) around in the drift and makes it readily available for the trout to eat. Very healthy river + superb fish condition + high water + lots of food = very good fishing and happy anglers.
March and April fishing was not nearly as good as normal due to several factors I will discuss later in this report. The most important difference from previous years was that the vast majority of fish, especially the larger fish, have been hanging out in the deeper water instead of the shallow riffles where they are normally found. The fish have been gorging on midges all spring, but have been super selective on the size of midges that they are eating. We have had to go deep (drifting from the boat) and tiny flies (size #20 to #24 midges). Earlier this spring, most all the fish we were catching were small. Then suddenly, in late April and early May, the larger fish started to show up. We can only figure that these larger fish were hanging deep the whole time and for whatever reason started to move back into water that was 3- to 10-feet deep – which makes them available for us to catch.
May 1 the water flows increased and the fish began to eat scuds (ginger #14 to #16 deer-hair back). This means that the scuds are beginning to drift in the higher water. The fish also began moving back into the shallows and wade fishing became much more productive in certain spots. We are still drifting out of the boat and with the forecast for higher than normal water flows (see below) we will be doing more drifting than wading throughout the summer months.
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’s 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 was then less than 50% of capacity. I believe that the large runoff mixed up the normally stratified water in the lake and as a result, the water that entered the river gradually increased in temperature and eventually went up to 58 degrees. This has happened 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 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.
Water Flow Outlook
The release volume for May, 2015 will be 700,000 acre-feet with fluctuations between approximately 8,500 cfs and 14,500 cfs. The anticipated release volume for June 2015 is 800,000 acre-feet with fluctuations between approximately 10,000 cfs and 18,000 cfs.
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.
We are hearing a few more positive reports on the walk-in area, but it is still very slow compared to normal. We are hearing of fish being caught in the deeper water more than the shallows. That is likely changing and if it is anything like upriver, the fish should start moving more into the shallows very soon. Also, we’re hearing that the fish being caught are noticeably larger than in recent years.
Spin fishing continues to improve. We’re hearing that the fish are very selective, much more so than normal. So be thinking lighter lines and fluorocarbon leaders to attach your lure.
Glen Canyon Dam / Lake Powell June 15 2015
The unregulated inflow volume to Lake Powell in May was 1,613 thousand acre-feet (kaf) (69% of average). The release volume from Glen Canyon Dam in May was 699 kaf. The end of May elevation and storage of Lake Powell were 3,597.3 feet (103 feet from full pool) and 11.49 million acre-feet (maf) (47% of full capacity), respectively. The reservoir elevation is increasing and will continue to increase throughout mid-summer as runoff from snowmelt and precipitation enter the reservoir.
To view the most current reservoir elevation, content, inflow and release, click on: Lake Powell Data.
To view the most current reservoir elevation projections, click on: Lake Powell Elevation Projections.
To view the 2015 progession of snowpack above Lake Powell, click on Lake Powell Snow Chart.
To view the current April to July 2015 inflow forecast relative to past inflows, click on Lake Powell Inflow Forecast
The operating tier for water year 2015 was established in August 2014 as the Upper Elevation Balancing Tier. The April 2015 24-Month Study established that Lake Powell operations will be governed by balancing 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 June 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 June, the release volume will be approximately 800 kaf, with fluctuations anticipated between about 10,000 cfs in the nighttime to about 18,000 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 July is 1,050 kaf with daily fluctuations between approximately 12,000 cfs and 20,000 cfs during the first part of the month and 14,000 cfs and 22,000 cfs during the latter part of the month. The expected release for August is 800 kaf with daily fluctuations between approximately 9,000 cfs and 17,000 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 June 3, 2015, by the Colorado Basin River Forecast Center, projects that the most probable (median) unregulated inflow volume will be 5.00 maf (70% of average based on the period 1981-2010). Due to significantly above average precipitation in May, the forecast increased significantly (by 2,000 kaf) since last month. There is still uncertainty regarding the runoff and resulting inflow to Lake Powell. The April to July forecast ranges from a minimum probable of 4.45 maf (62% of average) to a maximum probable of 6.00 maf (84% 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. Because the April 2015 24-Month Study projected 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, Lake Powell operations shifted to balancing (Section 6.B.4 of the 2007 Interim Guidelines) 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 June 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, last update in April, the water year release is projected to be 8.9 maf. Under the maximum probable inflow scenario, last updated in April, the release is projected to be 9.0 maf. There 10% chance that inflows will be lower than the 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 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 June 24-Month Study projects Lake Powell’s end of water year 2015 elevation to be near 3,596 feet with approximately 11.34 maf in storage (47% capacity). Projections of elevation and storage still have uncertainty at this point in the season, primarily due to uncertainty regarding runoff and the resulting inflow to Lake Powell. Under the minimum probable inflow scenario, last updated in April, the projected end of water year elevation and storage are 3,574 feet and 9.45 maf (39% capacity), respectively. Under the maximum probable inflow scenario, last updated in April, the projected end of water year elevation and storage are 3,603 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 8.54 maf (79% of average), and ranges from a minimum probable inflow of 8.0 maf (74%) and maximum probable inflow of 9.5 maf (88%).
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 2015. 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 28.8 maf (48% of total system capacity). The actual end of water year system 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 June 15, 2015