Extreme Drought Effects on the Colorado River in Grand Canyon

Will The Extreme Drought Affect My Grand Canyon Rafting Adventure?

By Sharon Hester-Updated 5/31/2023

If you have heard about the long-term extreme drought and effects of climate change on the Southwest region and Colorado River system, and have concerns, you’re not the only one. AzRA is also worried for the communities and ecosystems of the region that all rely on Colorado River water to survive.  Much will have to change, such as water conservation practices and water regulations/law soon for the regions that rely on Colorado River water to continue to thrive.   

We hear the question, “will the river be too low to raft?” a lot from our rafting participants. With the current information available to us, not having enough water to raft the Colorado River in the foreseeable future due to regional drought is not a concern for us at this time. You may ask how can that be, we have heard so much about the extreme drought? Let us explain! 

The Colorado River and the Colorado River Compact

The Colorado River is a large volume and heavily regulated river system. The 100-year-old federal act, the Colorado River Compact mandates that the upper basin states (CO, WY, UT, NM), where most of the water is created by snowpack, deliver 8,230,000-acre feet annually to the lower basin states (CA, NV, AZ). This figure includes Mexico and Indigenous Tribes’ allocations. That amount can be averaged out over a 10-year period. With the current regulations, even in a heavy shortage year scenario, 7,000,000 acre-feet/year (7 maf) must still flow down through Grand Canyon from the upper basin states to the lower basin states. However, this flow regime is likely to be decreased in the upcoming years.   

For a bit of perspective, 8.23 maf (million acre-feet/year) equates to a median water release of about 12,000 cubic feet per second (cfs) per day from Glen Canyon Dam/Lake Powell. That includes both the higher flows in mid-summer and the lower flows in the shoulder months and winter. In 2022, the lower basin water users saw a reduction of flow from 8.23 maf to 7 maf.  At the 7 maf, this averages out at about 10,615 cfs per day spread out over the year. The 2022 rafting season saw flows between 7,000 to over 16,000 cfs. These flows are great flows for rafting. For perspective the river has been successfully navigated (in both motor and oar rafts) at flows as low 3,000 cfs. It is interesting to note that prior to Glen Canyon Dam being built (prior to 1963), the average annual flow of the river was about 8,000 cfs. 

Changes to the Colorado River Compact?

There are a lot of powerful stakeholders and interest groups that use the Colorado River water. Changing the parameters of the Colorado River Compact is a huge, complicated legal endeavor, which will affect many water municipalities of both the upper and lower basin states. Making the necessary changes to assure adequate flows for power demands, cities, agriculture and the environment will surely be a long and painful process, and sacrifices will have to be made for everyone that relies on the river

The water allocations of the Colorado River Compact are almost certainly going to be further reduced due to a lack of stored water in the upper basin states, however, it is unlikely that there would not be enough water flow to raft through Grand Canyon. As long as there is snow melting from the Rocky Mountains, water will go through Grand Canyon to feed the thirsty cities and farmlands further south. And/or to insure power demands, which require water going through the dam’s turbines. The river is runnable at very low flows, so rafting in Grand Canyon is not at risk of stopping anytime soon due to water reductions. 

If the Colorado River through Grand Canyon National Park were to become ever so low as to not be navigable, then most southwestern communities would have enormous issues to contend with, and rafting will be the least of our worries for those of us who live in the region. Sadly, this could happen with more years of continued drought/climate change and not effectively applying the necessary conservation measures and changes to water allocations. However, with careful planning and changes in water conservation efforts, humans will hopefully still be able to live in the region AND have rafting adventures on the Colorado River for generations to come! 

UPDATE to 2023 Season:

We expect no impact to rafting in Grand Canyon, and expect 2023 water releases from Glen Canyon Dam to be similar to 2022, if not higher. River flows in 2022, while slightly lower than 2018 and 2019, were still great flows for rafting.  River flows, per normal operating procedures, are lower in April, May, Sept and October, due to decreased power demands in the cooler spring and fall seasons. The highest flows are typically in June July and August, with August usually having the highest releases.

For the 2023 rafting season, the Bureau of Reclamation has stated in its most recent news release regarding 2023 operations dated August 16, 2022, that it will release at least the same amount of water to lower basin states as 2022 (which was 7 maf) from Glen Canyon Dam. It is very possible with the high snow pack upstream they may release flows to do what are called “balancing flows”.  In the section of this article titled, 2023 Operations of Lake Powell, they say, “The Department will evaluate hydrologic conditions in April 2023 and will implement the Interim Guidelines Section 7.D by limiting water year 2023 releases (with a minimum of 7.0 maf) to protect Lake Powell from declining below 3,525 feet at the end of December 2023.”  If that is true, then flows in 2023 should be similar to 2022. Of course, their prediction is subject to change as needed, based on the snow pack and upper basin release flows into Lake Powell during the spring of 2023. It is likely that at some point in the future, flows will have to be reduced further, but when and how much remains to be seen. The probable further cuts will be big news. And it will be a painful and expensive change for states and cities that rely on Colorado River water. However, as long is there is enough water to sustain those cities and humans residing in the southwest, there will be enough water for rafting. 

Predicted June Flows: A 5/30/23 email from the Bureau of Reclamation states “Hourly releases during June 2023 will fluctuate from a low of approximately 13,300 cfs during the early morning hours to a high of 19,530 cfs during the afternoon and evening hours on the weekdays, and a low of 11,530 cfs during the early morning hours to a high of 19,530 cfs during the afternoon and evening hours on the weekends, with a potential for steady releases averaging approximately 17,900 cfs anytime during the month.” These flows are higher than previously predicted water releases based on Lake Powell levels and prior to the higher than average snowpack in the mountains that feed the Colorado River. Keep in mind there can be extra water that adds to the dam releases from flooding in side streams. Those side stream floods are temporary and usually do not have a great affect on river levels, but occasional can create a sharp short term spike in the base flow.

The Effects of Lower Water Flows: Pros and Cons

Update to information below. Due to record high snow pack during the winter of 2022/23 the Department of the Interior is now planning on increasing 2023 flows from previous predicted lower average flows.  The information below is still valid for future years when flows will most likely have to be lower due to low water storage in the reservoirs. Also, every trip has a daily low and high flow regime, so the information below is still applicable to any trip.

When all is said and done, even with projected lower volume water flows which will certainly happen in the future, there should still be plenty of water to raft through Grand Canyon. Many rapids in Grand Canyon are more challenging at lower flows. Some rapid have waves that are biggest at lower flows, and other rapids become washed out at higher flows.  Grand Canyon rapids are always exciting at any given water flow!

The benefits to lower water flows due to lowered lake levels:

• The beaches will be bigger and more plentiful. Better camping options over all.
• The water will be warmer and nicer to dip in, play in, be splashed by, and bathe in. This is due to the warmer surface waters of Lake Powell being drawn into the dam intake pipes due to the lower lake level. It used to be that when lake levels were higher, the intakes were farther beneath the surface in colder deeper water, therefore the water temperature was always extremely cold.

The drawbacks to lower water flows:

• Lower water means slower water speed. This could result in less time for hiking at the lowest flows, but that can often be mitigated by getting an earlier start in the mornings. It will also take more effort to row or paddle rafts down river in the flat sections. These are not an issues on motor trips; hiking time should be similar on motor trips no matter the flow.
• Warmer water means your beverages that we chill in “drag bags” that hang off the raft into the water will not be as cold as in previous years.
• Warmer water will likely also create ecological changes to an already very modified ecological environment (created by Glen Canyon Dam and other upper basin dams). The river prior to the dam was warm and muddy most of the year. After the dams were filled, the flows became very cold (and not as muddy), this changed the habitat for many plants and animals that lived in the Colorado River pre dam. Introducing warm water back into a now cold river into a relatively stable system (even though not natural) will make for more ecological changes, as some plants and animals have adapted to colder flows. We have seen some environmental changes already with warmer flows, but one we notice has quickly changed is an increase in foot infections on trips. Learn how to prevent them from happening on your river trip. 
• The possibility of dories not being on some Classic Adventures if they’re damaged.

For more information and news, these links below provide more in-depth information, and the most updated flows:

Current and historical water flows and temperatures in the canyon 

Projected releases from Lake Powell/Glen Canyon Dam    

Possible modifications to Glen Canyon Dam from August 18 2022

May  2023 24-Month Study Report  

Please note on any given year there is always the possibility of temporary emergency extreme low flows due to power grid issues or other emergencies. 

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