My emphasis added in bold.

Don’t blame climate for Colorado River’s woes

By Roy Johnston Sep 7, 2022 Updated Sep 9, 2022

The most important long-term issue for Colorado today is the same as it was 120 years ago: water. In 2010, Smithsonian Magazine published an article titled, “The Colorado River Runs Dry.” The article included a quotation from Brad Udall of Colorado State University: “Climate change will likely decrease the river’s flow by 5 to 20 percent in the next 40 years.”

On Aug. 25, Mr. Udall told the Steamboat Pilot & Today, “This isn’t a drought, it’s something else. Myself and other scientists are trying to use a different term: Aridification.” In defining “aridification,” he said, “declining snowpacks, it’s earlier runoff, it’s a shorter winter, it’s more rain, less snow, it’s higher temps. It’s drying soils, it’s severe fires, it’s forest mortality, it’s a warm, thirsty atmosphere.” The only issue with this quote is it is mostly erroneous. There is a slight warming trend since 1993; thus, the atmosphere holds more moisture and precipitation is on a slight incline.

There is a reason the southwest is called the “desert southwest.” With the exception of the Rocky Mountains, it does not rain out here very much. The USDA records the average annual precipitation in the Rockies at 21-40 inches-per-year between 1961 and 1990, with more than 50 inches common. The decadal average precipitation throughout the basin has not changed since 1901. The last decadal average being 2011-2019. The highest precipitation for Denver was 16.18 inches (1991-2000) and the lowest was 12.8 inches (1931-1940). Not much variation over the past 100-plus years. Bottom line: precipitation across the Colorado River basin is not declining and thus the river is not “drying up” — at least, not in the upper basin.

Does that mean there is no water crisis? No. There is a crisis, but it is not caused by climate change or drought or “aridification.”

If you Google Colorado River, you will find pages of popular articles projecting doom and gloom for the river. These articles are all long on anecdotes (i.e., stories/reminiscences) and emotion but very short on facts. I have cited the decadal averages for precipitation; this “climate” data proves there is no alarming trend.

So, what about temperature? Let’s focus on Colorado. The following data is from all ground-based weather stations in Colorado and represents the state average maximum temperature. If we start at 1993, then Colorado maximum temperature has increased 3 degrees Fahrenheit. If we stopped there, it would be alarming. But, if we start with 1931, Colorado has cooled 2 degrees Fahrenheit. The graph of data from 1901 to 2022 shows a slight cooling trend. The average in 1901 was 3 degrees Fahrenheit warmer than 2022. Bottom line: average temperature in Colorado shows no strong warming (or cooling) trend during the last 120 years.

So, what gives? The data for precipitation and temperature is all good news. The crisis, however, is starkly clear when one looks at the water levels at Lake Powell and Lake Mead.

If a popular article includes data, it is usually concerning the water level at these huge reservoirs that store water for Phoenix, most of Arizona, Las Vegas, Los Angeles, San Diego and Southern California. Hence, the cause of the problem: people and politics.

The flow rate of the upper basin, when adjusted for human off-take (mainly municipalities, cities and agriculture) fluctuates cyclically but the long-term trend is virtually unchanged. In the “old” days, the primary demand for river water was agriculture. What has changed is the number of city dwellers now needing water.

Phoenix has grown 432% since 1970. Las Vegas is up 1,082% since 1970; Los Angeles is up 49%, or 4.1 million, and Denver has grown 174%.

Bottom line: Lake Powell and Lake Mead levels are down because of population growth, primarily in the lower basin. Water demand has exceeded the normal replenishment rate in Lake Mead. River-flow rate into Lake Powell, adjusted for human off-take, is normal. The climate change Boogieman is not to blame.

Peter Gleick of the Pacific Institute told the LA Times that scientists have warned politicians and water management bureaucrats for years. He was an author of one of these early warnings in 1993, 30 years ago. “If we had cut water use in the Colorado River over the last two decades to what we now understand to be the actual levels of water availability, there would be more water in the reservoirs today,” Gleick said. “The crisis wouldn’t be nearly as bad.” Notice, he did not blame climate change.

The “scientists,” “experts,” politicians and water bureaucrats have the data I have reviewed.

Roy Johnston is a retired university professor who holds a Ph.D. in plant science and genetics, and a retired corporate executive.

Never let a crisis go to waste, it's clear that places like Las Vegas, LA, Phoenix have water issues, over growth, and combine that with climate change driven politics, a recipe for disaster.

Turn off the power to LA, reduce the amount of water allowed to be used until the lake recovers, it's the only ecologically sound method to save the environment of the CO River...

For perspective on water released through the dam, they're releasing over 20k acre feet a day, every day.

Source: https://www.usbr.gov/lc/region...0/hourly/levels.html

According to the Bureau of Reclamation, this is false. Much less inflow into the upper basin.

The key paragraph

quote:

Upper Colorado River Basin regularly experiences significant year to year hydrologic variability. The 30-year average was updated in October 2022 from 1981 through 2010 to 1991 through 2020. Shifting the period of record decreased the average unregulated inflow 1.20 maf. The period 2000-2021 is the lowest 22-year period since the closure of Glen Canyon Dam in 1963, with an average unregulated inflow of 8.46 maf, or 88 percent of the 30-year average (1991-2020) with only five above-average water years. (For comparison, the 1991-2020 total water year average is 9.60 maf.) The unregulated inflow during the 2000-2021 period has ranged from a low of 2.64 maf (28 percent of average) in water year 2002 to a high of 15.97 maf (166 percent of average) in water year 2011. In water year 2021 unregulated inflow volume to Lake Powell was 3.50 maf (36 percent of average), the second driest year on record above 2002. Under the current most probable forecast, the total water year 2023 unregulated inflow to Lake Powell is projected to be 8.3 maf (86 percent of average).

The link

https://www.usbr.gov/uc/water/...e%20is%209.60%20maf.)

Thanks for bolding the main point. It does seem a reasonable explanation.

They have been allocating more water to the various states than flows into the reservoir for decades. If they just limited it to what flows in, there would be no problem.

And global warming results in more precipitation, not less.

Colorado snowfall has been within 80 percent of normal this year I think. We've had some years where its been well above average. As pointed out its the lower basin that's the problem. Too many people living in the desert with piss poor water management. But, climate change is a hammer in search of a nail. This year is still not nearly as bad as 2002. That year the Arkansas river through my town dried up for two weeks. First time in my life time that's ever happened.

quote:

Originally posted by BBMW:
According to the Bureau of Reclamation, this is false. Much less inflow into the upper basin.

The key paragraph

quote:

Upper Colorado River Basin regularly experiences significant year to year hydrologic variability. The 30-year average was updated in October 2022 from 1981 through 2010 to 1991 through 2020. Shifting the period of record decreased the average unregulated inflow 1.20 maf. The period 2000-2021 is the lowest 22-year period since the closure of Glen Canyon Dam in 1963, with an average unregulated inflow of 8.46 maf, or 88 percent of the 30-year average (1991-2020) with only five above-average water years. (For comparison, the 1991-2020 total water year average is 9.60 maf.) The unregulated inflow during the 2000-2021 period has ranged from a low of 2.64 maf (28 percent of average) in water year 2002 to a high of 15.97 maf (166 percent of average) in water year 2011. In water year 2021 unregulated inflow volume to Lake Powell was 3.50 maf (36 percent of average), the second driest year on record above 2002. Under the current most probable forecast, the total water year 2023 unregulated inflow to Lake Powell is projected to be 8.3 maf (86 percent of average).

The link

https://www.usbr.gov/uc/water/...e%20is%209.60%20maf.)

So they dropped the decade that had the unusual 1982-1983 years that almost overtopped the Glen Canyon dam, and now include the decades that include mostly the drought. I don’t see how that contradicts data that goes back 120 years.