Water for 100 Years of Arizona Growth With Continued Conservation and Augmentation

Mark Lewis
VP Engineering, Water Resource Institute


Arizona has enough water for our growing population, because of our long-running conservation efforts. We just need to help farmers and businesses increase efficiency and gain more crop per drop, on the existing farms and businesses. AZ has grown by over 100% and we are using less water as we did back in 1970i. 

We have 110 years of water conservation and augmentation mindset that is unique in the US. From 1890 to 2019 in the SRP renewable water supply system. We have 100 years of future water supply systems in place from the Central AZ Project renewable water supply system stored from flood events over the past 30 years along the Colorado River.

However, more conservation and efficiency is the process over the future 100 years as we look at new technology, changing growth patterns, and better conservation efforts in AZ. Arizona’s major urban areas have been insulated somewhat from the impacts of drought because of large amounts of water storage and CAP water in excess of current needsi. Water conservation technology is changing quickly while AZ farmers in central AZ had new technology that helps farmers use water better gaining support for More crop per dropiii.


Beyond AG conservation, water supply augmentation for the years 2070 to 2100 are on our long term 22nd Century planning horizons, with Desalting, and drip irrigation farming methods.

Augmentation of water supplies is also on our water conservation list. AZ has a lot of groundwater that is so salty you can’t drink it or grow crops with it. We already have a $300 million dollar USBR desalteriv that is not being used in Yuma because of the high cost of running the plant. We are looking at desalting for 2070 and beyond.

Arizona’s prospects for desalinating its enormous underground deposits of brackish water, notably in: the Yuma Brackish Groundwater Mound; 

A recent study indicates that “50,000 acre-feet of (potable) water per year” could come out of that mound of saline water at the cost of about $550 per acre- footiv. DWR Director, 2018. 

Cities, water companies, farmers and tribes have partnerships set up to use the full entitlement of Colorado River water supplies so that California does not take our water future. We are last on the list for priorities when it comes to drought cutbacks. Which is why AZ has been funding the Drought Conservation Plan, (DCP) over the past two years.

We have a plan and the money to temporarily cut back on water use in the farming fields so that cities will never have to experience a full water shortage.

The final word on water is we have lots of water for millions of new residents if we conserve and augment our supplies, using the $4 billion dollars worth of water conservation structures we already have now.

i Experts Weigh Plusses And Minuses Of Augmenting Arizona’s Water Supplies; new.azwater.gov/news/articles/2018-12-01 ii Water and Growth; wrrc.arizona.edu/sites/wrrc.arizona.edu/files/Water-and-Growth.pdf

iii. Satellite imagery to reduce water use and improve crop performance in drought-stricken Arizona; blog.fieldmargin.com/2019/05/08/using-satellite-imagery-to-reduce-water-use-and- improve-crop-performance-in-drought-stricken-arizona/

iv. Yuma Desalter operated by the USBR. usbr.gov/lc/yuma/programs/desalting_services.html v new.azwater.gov/news/articles/2018-12-01