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Colorado river cutbacks in Arizona

flowerbug

Well-Known Member
I live in the inland part of SoCal. My city allows grey water systems. My biggest household water uses are the washing machine and tub and shower. These are plumbed into a cistern that pumps the non sewage uphill to irrigate about a quarter acre of native trees, fruit trees, and aloe that forms my fire break. Drinking water isn't used on the landscaping. No lawns in my neighborhood!

We're trying to figure out a companion system to gather what little rain runs off the roof to irrigate another quarter acre on the other side of the house. That won't work but a couple of months a year, but it's worth doing. Huge amounts of water run off the hill behind the house and onto the fire road at my property line, but that would require a Olympic swimming pool sized cistern, and I can't see myself ever making that happen.

Still, I'm trying to do my part.

there are a lot of things that you can do in an arid climate to grow plants and even vegetables, but you do have to be willing to do some actual work. :) there are plenty of good things to learn from permaculture and i'm glad to see that many of the things practiced by others in arid climates do actually get picked up and used in other places.

setting up your land to slow, spread and soak in whatever water that falls on it and to learn how to use different methods of doing that. the most basic point though is that you must make sure your geology won't slip away from beneath you if you super-saturate it with retained water. same for building any dams or water retention systems - there are some things you want to know first before building dams or other retaining walls.
 

flowerbug

Well-Known Member
Thanks for the charts and other details.

Cities like LA could install desalination plants. Thus, need to grab less Colorado, Owens Valley, and other river water.

they've already done a great deal to install water recycling processes and wetlands and places to sink water or even injection wells to recharge the aquifers. more is happening all the time.


-2- There are more than 24 major trans-mountain diversion tunnels from western to eastern Colorado under the Continental Divide. Thus less water headed to Lake Powell.

yes, and a few more in the works too i think, but in a short number of years it's pretty likely that they won't be able to do much more because there won't be water available in enough quantities to make it worth doing.

already New Mexico has found out that for the money they wanted to spend there just wasn't enough reliable water left in the Gila River to divert any more - they also had a lot of opposition from people who wanted an actual functional river left there too so that was a good thing.

a lot more can be done with conservation. do that first and you don't have to ruin a river ecosystem or pump so much water from the ground that the area sinks or salt water intrudes from the neighboring oceans or ...
 

Colorado Expat

Active Member
Thanks for the charts and other details.

Cities like LA could install desalination plants. Thus, need to grab less Colorado, Owens Valley, and other river water.

-2- There are more than 24 major trans-mountain diversion tunnels from western to eastern Colorado under the Continental Divide. Thus less water headed to Lake Powell.
Yes, there are a large number of trans-basin diversions from the upper Colorado system to the Platte catchment to serve the needs of Denver and other eastern slope municipalities. But those were mostly all built many decades ago, and have taken the easily obtainable water from the sites that were the simplest to bore from. Another diversion from Homestake Reservoir in the upper Eagle River basin is currently being proposed, but is heavily opposed by Western Slope interests. Any new diversions will be more expensive than the old ones, will meet with more concerted local opposition from trout fishermen and others, and will have to comply with an expanded legal framework including NEPA and other laws that were not on the books when the original diversion tunnels were drilled. The other consideration is that the Colorado is a gaining system, so the further downstream you go, the more water you can catch, an increasingly important consideration as precipitation in the basin falls more as rain than as snow with the warmer winters now prevailing. Overall, I would not think that any future diversions to the Eastern Slope that might plausibly be built in the next twenty years will have any significant impact on the amount of water reaching Lake Powell, since as noted before, the main stem Colorado River is free flowing all the way from Granby to Canyonlands, representing the aggregate runoff from numerous sub-basins, many of which cannot be realistically tapped by Denver. The larger consideration will be how much water is retained in the Upper Basin reservoirs collectively, versus being passed through to the much larger population base in the Lower Basin states.
 

drewsxmi

Well-Known Member
Okay, not a graph, but a table of inflows vs. outflows from Lake Powell, every year since 1964... But the takeaway relative to Lake Mead is that apart from gargantuan outflows from Lake Powell from 1983-87 and some big outflows from 1996-99, it's been pretty consistent through the years, usually 8.0-8.3 maf... and actually surprisingly high outflows from 2015-19... So the projected outflow of 7.48 maf in 2021-22 is going to be tied with 2014 for the lowest outflow from Lake Powell since 1964, when they really suppressed outflows in order to fill the lake. (Actually, 2014 outflow was 7.45 maf, slightly less than expected in the coming year). Here's the data:

View attachment 16101
There is something a little fishy (to keep on topic with the forum) about those numbers. If you tally up the net numbers, the lake should be full around 1973 at 27 maf. By 1980 when the lake actually did fill all of the way up the cumulative tally was about 40.7 maf. If we figure the actual capacity (including minimum reserve) as about 27 maf, there is a missing 13 maf between 1964 and 1980. If you take the average inflows and outflows for the whole life of the lake, the inflow is .89 maf greater than outflow. Currently the lake is officially 7 maf (probably more like 10 maf with minimum reserve), but the cumulative tally is about 52 maf.

I see a couple possible reasons for the discrepancy:
1. Inaccuracy in measuring inflow
2. Seepage (also considered "bank storage" which should taper off over time and come back at lower water levels)
3. Evaporative loss

I also tallied up the excess releases (in excess of 8.25 maf / year) over the full life of the lake, and came up with 85.95 maf, or an average of 1.5 maf / year. In the last 20 years (2001 - 2021) there has not been any appreciable excess water sent downstream except in 2011 and 2012.
 

JFRCalifornia

Escalante-Class Member
Yep, I noticed a similar discrepancy, and came to similar conclusions. Evaporation might account for 0.5-0.8 maf per year depending on who you ask. Seepage? Who knows? And although the numbers are small, the City of Page and Navajo Generating Station use (or used in the case of the power plant) water from Lake Powell.

But this might collectively explain the difference, and could be a good way to estimate seepage.
 
I have a friend who built Desal plants in the Middle east and other parts of the world , they tried to do so here in SoCal , They have built one plant that serves a community of over 100,000 homes over and over again , the issue is SoCal and all of KaLiFoRnIa IS Government Regulations and Environmentalist At one point my friend mentioned that in order to build a plant in SoCal they would have to redesign a plant that has proven its self over and over and just to meet OSHA and the UBC "Uniform Building Code and other Hurdles it would take a Minimum Of 10 years and and Estimated Cost increase of over a Billion OR MORE dollars , It took 14years to get a permit to raise a Dam in San Diego 100 feet because the environuts wondered what would happen to all the Birds bees and other critters when water levels go up and down the last I looked so Government has the Solution but absolutely no Clue on the problem they only have to look in a Mirror ....Sorry
 

Bill Sampson

Escalante-Class Member
I have a friend who built Desal plants in the Middle east and other parts of the world , they tried to do so here in SoCal , They have built one plant that serves a community of over 100,000 homes over and over again , the issue is SoCal and all of KaLiFoRnIa IS Government Regulations and Environmentalist At one point my friend mentioned that in order to build a plant in SoCal they would have to redesign a plant that has proven its self over and over and just to meet OSHA and the UBC "Uniform Building Code and other Hurdles it would take a Minimum Of 10 years and and Estimated Cost increase of over a Billion OR MORE dollars , It took 14years to get a permit to raise a Dam in San Diego 100 feet because the environuts wondered what would happen to all the Birds bees and other critters when water levels go up and down the last I looked so Government has the Solution but absolutely no Clue on the problem they only have to look in a Mirror ....Sorry
There is a power generating station on Pacific Coast Highway in Huntington Beach that has been proposed as a desalinization plant for years. It is already there, so that is a plus, but the environmentalists don't want it used for that.
 
There is a power generating station on Pacific Coast Highway in Huntington Beach that has been proposed as a desalinization plant for years. It is already there, so that is a plus, but the environmentalists don't want it used for that.
And folks wonder why things cost so much 14 years and hundreds of thousand's if of not Millions of dollars later its up and running and guess what not one dam fish or bird died while building it ! But Our Government knows Best what good for us ..........Bull $HIT

The plant took nearly 14 years to permit, design, and build.
Location: Encina Power Station, Carlsbad, Cal...
Percent of water supply: Estimated 7% of San ...
Estimated output: 50 million US gallons (190,0...
Technology: Reverse osmosis



Claude "Bud" Lewis Carlsbad Desalination Plant - Wikipedia​

 

Colorado Expat

Active Member
Okay, not a graph, but a table of inflows vs. outflows from Lake Powell, every year since 1964... But the takeaway relative to Lake Mead is that apart from gargantuan outflows from Lake Powell from 1983-87 and some big outflows from 1996-99, it's been pretty consistent through the years, usually 8.0-8.3 maf... and actually surprisingly high outflows from 2015-19... So the projected outflow of 7.48 maf in 2021-22 is going to be tied with 2014 for the lowest outflow from Lake Powell since 1964, when they really suppressed outflows in order to fill the lake. (Actually, 2014 outflow was 7.45 maf, slightly less than expected in the coming year). Here's the data:

View attachment 16101

Okay, not a graph, but a table of inflows vs. outflows from Lake Powell, every year since 1964... But the takeaway relative to Lake Mead is that apart from gargantuan outflows from Lake Powell from 1983-87 and some big outflows from 1996-99, it's been pretty consistent through the years, usually 8.0-8.3 maf... and actually surprisingly high outflows from 2015-19... So the projected outflow of 7.48 maf in 2021-22 is going to be tied with 2014 for the lowest outflow from Lake Powell since 1964, when they really suppressed outflows in order to fill the lake. (Actually, 2014 outflow was 7.45 maf, slightly less than expected in the coming year). Here's the data:

View attachment 16101
I did a casual search of Bureau of Reclamation publications to see how much water the Upper Basin states actually take out of the Colorado River basin. Between 2011 and 2013 the the Upper Basin states used an average of 4.5 maf. Figures from more recent years indicate that on average between 2016 and 2020 the Upper Basin use was 4.6 maf, which is only about a 2 percent increase. So Upper Basin demand has not greatly increased over the past 10 years, even though the major cities there (all of which lie outside the Colorado River basin per se) have grown substantially during that same period. My guess is that total Upper Basin use may reach 5 maf by 2030 when a few additional trans-basin diversion projects come on line, but that is still not a giant increase, given that the Upper Basin is technically entitled to 7.5 maf if they want it.

This comes back to the point that it is rapid increases in Lower Basin demand (ie., Arizona) which have put the current stresses on the Colorado River. If we add up current Upper Basin use and Lower Basin allocations, it comes out to 12.1 maf, which is what the river needs to deliver just to satisfy current off-stream demands. Only when discharge is above that through the basin as a whole is there water left over to capture in Lake Powell or Lake Mead. Given the useful table of inflows and outflows provided by JFR, it is easy to see why both dams are now in crisis mode. We have only managed to clear that 12.1 maf bar 9 times in the past 22 years, so we are now in a one-step-forward-two-steps-back situation.

Adding the Upper Basin withdrawals back into to recorded Lake Powell inflows would indicate that a free-flowing river un-utilized in any form by the Upper Basin states would have delivered 8.6 maf to Lake Powell in 2021. That would have been barely enough to provide the Lower Basin its minimum 7.5 maf allocation and still keep Lake Powell on life support when evaporative and seepage losses are also factored in. As JFR noted, it is a tough sled ahead, and it is hard to see how we ever regain full pool in Lake Powell going forward even if the hydrological cycle moves back to a slightly wetter phase. There is just too much aggregate demand on the system now.
 

JFRCalifornia

Escalante-Class Member
I did a casual search of Bureau of Reclamation publications to see how much water the Upper Basin states actually take out of the Colorado River basin. Between 2011 and 2013 the the Upper Basin states used an average of 4.5 maf. Figures from more recent years indicate that on average between 2016 and 2020 the Upper Basin use was 4.6 maf, which is only about a 2 percent increase. So Upper Basin demand has not greatly increased over the past 10 years, even though the major cities there (all of which lie outside the Colorado River basin per se) have grown substantially during that same period. My guess is that total Upper Basin use may reach 5 maf by 2030 when a few additional trans-basin diversion projects come on line, but that is still not a giant increase, given that the Upper Basin is technically entitled to 7.5 maf if they want it.
Very nice analysis, concise and focused. The only thing I'd add is that there are really three major water "sinks" in this game (not counting Mexico): the Upper Basin states, Lower Basin states, and the storage in the two big reservoirs. It's a very difficult relationship.

In very rough terms under the Law of the River, the Upper Basin's obligation is to provide 75 million acre feet in any 10-year period to the Lower Basin through Glen Canyon Dam (plus its share of water to Mexico). What that means is that the Lower Basin is guaranteed to get its 7.5 maf every year (on average), as long as there's enough water in Lake Powell to deliver that amount, which has always been the case so far.

It's a little different in the Upper Basin. Although it seems they are entitled to 7.5 maf per year, that's not really the case. They can theoretically get up to that much, but only after they deliver enough water to the Lower Basin per the requirements described above. In simple terms, that means they only get leftover water, which could be considerably less than 7.5 maf. It's almost like having to pay the loanshark first, which might leave you with nothing. And how can you tell that the Upper Basin is really using more than its sustainable (legal) share? When Lake Powell keeps going down.

The tricky part is this: at what point do Upper Basin diversions count against what would otherwise be delivered downstream to the Lower Basin? That is, are the Upper Basin states cheating the agreement by diverting water before it really gets too far downstream into the system to be counted? That's a question for lawyers, but a dwindling Lake Powell provides all the evidence you need.

My point is that when the Upper Basin states are consistently using 4.6 maf +/- every year, they can (and will) try to get away with that as long as enough water remains to deliver to Lake Powell, and then beyond through the dam. And it works, sort of, because water accounting in a fluctuating system is fuzzy at best. But how can they be sure there will be enough left for Lower Basin delivery to do that in any given year? Hard to know, especially when you're dealing with delivery in terms of rolling 10-year periods. Its almost like a farmer taking out a loan to finance this year's crop, and counting on the crop coming in so he can make enough money to repay the loan. But if the crop fails, he can't repay the loan, and the farmer's bank forecloses...

And that is exactly what the Upper Basin potentially faces every year if the drought cycle continues. They will be forced to cut back (perhaps drastically overnight) if they can't make their required delivery to the Lower Basin. And so their strategy is to pump all they can right now in order to establish some sort of theoretical (and dubious) "prescriptive" right to the water when the inevitable fight between Lower and Upper basin states occurs (assuming they can't all amicably figure it out in advance). It's a mess.

And of course, the big loser in all the Upper Basin strategy right now is Lake Powell. That's because it's in the interest of the Upper Basin to pump all it can before any water reaches Lake Powell, leaving only barely enough in the lake to deliver the 75 maf every 10 years. From their perspective, excess water left behind in Lake Powell means the Upper Basin states didn't do their job. And as Denver, SLC and other portions of the Upper Basin that siphon off water continue to grow, expect the pressure on Lake Powell to mount. But of course, if those states push that game too far, then not only will they risk being in default in terms of downstream delivery, they will have cut off significant power supply if Powell gets too low. Again, a huge legal mess, as well as an economic, ecological, and recreational one... And of course, somebody's going to be without water...

And incidentally, a "Fill Mead First" strategy, such as advocated by GCI, would eventually leave the Upper Basin without any reliable water under the Law of the River, since at some point they could no longer control downstream deliveries to the Lower Basin. And that might leave the GCI offices without water…
 
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low_rider

Member
Follow those of you interested their was a book & documentary series from the mid 1980's called Cadillac Desert. Covers the water policies of the Southwest. Good information & history!

The documentary is now on YouTube.
 

Colorado Expat

Active Member
Follow those of you interested their was a book & documentary series from the mid 1980's called Cadillac Desert. Covers the water policies of the Southwest. Good information & history!

The documentary is now on YouTube.
You are correct that Cadillac Desert is a classic, and required reading for anyone who wonders how we got to where we currently are with Lake Powell and the Colorado River as a whole. However it only tells the story of water in the West up to when it was published, in 1986. It is unfortunate that author Marc Reiser did not live to see how the rest of the story played out over the following 35 years, due to his untimely death from cancer at age 51. Many of the limitations that he warned of in regard to development in the West are now confronting us head on. The final chapter of his book was titled “A Civilization, If You Can Keep It” which seems to perfectly summarize where we are today.
 
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