Friday, July 03, 2009

13 million acre feet of water...

Allow me to be the first to admit that when it comes to groundwater supplies in Mohave County, I'm the last person on earth that could accurately guess how much is under our very feet at this moment. However I still maintain the ability to find knowledgeable information resources because of this here thing called the Internet.

But even with what I'm about to share, and offer some scenarios, I ask that you seek out your own knowledgeable resources to determine your own conclusions. If you do, check them against what I am sharing here, let's compare notes, and perhaps have a nice conversation about what we have come to find out in our investigations.

I've never tried to speak with authority on important water issues here in the Kingman area. When I write a blog post here about the subject I always include a link to where I got the information I use to draw any conclusions, guesses, or play out scenarios.

Ever since I first became interested in water availability as a citizen of Kingman I have either listened intently or read thoroughly when others have offered information. I have listened to all sides of the water argument and over time I've been privy to shared information such as; there is an underground waterfall in one of the aquifers that spills zillions of gallons of water and in effect is a vast underground river with limitless supplies... to the highly reactive "oh my goodness, we will be out of water if another golf course is developed here in Mohave County". I'm just going to guess that perhaps the real story about the groundwater will eventually be found somewhere in between.

This blog post is not an attempt to find the real story about the groundwater resources, simply put I'm sharing another information resource to perhaps draw some rudimentary conclusions from.

I found this report on the Internet at the Arizona Department of Water Resources website. It is actually a USGS report. Below is some of the text included in that report under a subsection 'Hydrology and Water Use'. The report was published in March of 2006 and comes complete with attributable annotations made from a collection of reports spanning many years.

Below is a copied portion from the report...

Ground water from the basin-fill aquifer is the primary water supply for each of the three valleys. The older basin fill is the primary water-bearing deposit because intermediate and younger basin fill are above the water table in most areas. Most ground-water withdrawals in the valleys are for municipal and industrial uses; a small percentage of withdrawals is used for agriculture. The combined annual ground-water pumpage for the three valleys was about 6,600 acre-ft in 1991; by 2000, pumpage had nearly doubled to about 11,000 acre-ft (Tadayon, 2005). The combined annual recharge for the three valleys was estimated to be about 9,000 acre-ft (Freethey and Anderson, 1986), and ground-water storage was estimated to be about 13 million acre-ft (Arizona Department of Water Resources, 1994). Regional ground-water movement in the basin-fill aquifer generally is from the mountain fronts towards the valley center and then along the valley axis to the Colorado River. In general, depths to ground water are greatest in the upper parts of the valleys and decrease downgradient to within a few feet below the land surface near the Colorado River. The greatest depths to water are about 1,200 ft near the boundary between Detrital and Sacramento Valleys (Dillenburg, 1987; Rascona, 1991), and about 600 ft near Kingman in the Hualapai Valley (Remick, 1981).

Local ground water in consolidated rocks serves as a water supply in some areas, especially where rocks are faulted, fractured, and weathered (Gillespie and Bentley, 1971). In the Kingman area, volcanic rocks are locally permeable near two fault zones, and ground-water stored in the fractures has been used as part of the municipal water supply. Several springs issue from consolidated rocks and in some cases serve as water supplies for livestock and wildlife.

My emphasis above and from that data I will use some math to draw some conclusions that you may or may not agree with. Before I do that I will repeat again that I am not an expert on water in any way shape or form (and I don't play one on TV). The data bit above about the groundwater storage in the three aquifers in this report totaling some 13,000,000 (million) acre feet of water is the center of my intrigue here. Yet I can't possibly know how or if it is possible to have access to that entire amount of water. However, I will presume that with todays existing technology that it is possible to tap all the groundwater resources -- if needed.

So on with the data...

From the data copied from the report above, the first thing I see is that the latest reported groundwater pumpage measured was 11,000 acre feet in 2005. The recent news of two proposed water using solar energy plants has brought up some discussion as to whether or not their reported heavy water use (3,000 acre feet a year on the high side) will negatively impact the water resources in the aquifers in Mohave County. So I want to figure out how long would it take for new growth (double the population) to empty out the aquifers. I'll double the use as reported in 2005 from 11,000 acre feet to 22,000 acre feet and even double the water use of the solar plants to 12,000 acre feet (to account for new commercial/industrial growth). When all is added up we are looking at 34,000 acre feet a year.

13,000,000 acre feet in the aquifers / 34,000 acre feet a year = just over 382 years of water.

That figure doesn't take into account the recharge rate of 9,000 acre feet of water as indicated on the report. 9,000 acre feet of water over 382 years comes out to 3.4 million acre feet of water or another 101 plus years of water at the usage rate of 34,000 acre feet a year.

So those conclusions are based on doubling the usage reported in 2005. Some folks believe this area will endure explosive growth (and some even tried to put a stop to it -- mission accomplished), fine I'll assume that the population uses 10 times more water than it was in 2005. I'll throw in another solar power plant or two as well. 11,000 acre feet x 10 = 110,000 acre feet. Four solar power plants using 6,000 acre feet of water a year = 24,000 acre feet. The total sum is now 134,000 acre feet of water usage a year.

13,000,000 acre feet in the aquifers / 134,000 acre feet a year = just over 97 years of water. Factoring in recharge and there is an additional 6.5 years of water.

No matter how you slice it, today there is plenty of water to use. Don't forget that even using the latter calculation, 97 years is a fairly long time and so much could change by then.

Arizona became a state 97 years ago.

The first flight between Paris and London took place 97 years ago, it took over 3 hours... today a train ride between the two cities takes 2.5 hours. Meaning that since that first flight, a large tunnel spanning a couple of hundred miles was engineered and fitted with a high speed train that moves all kinds of people to and from in less time than a previous technological marvel did decades ago. It took less than 10 years to build that tunnel to make it all happen.

That leads me to believe that in the future it won't likely be all that much a engineering marvel when the federal government, or a consortium of western states, get with the times enough to build a pipeline and a de-sal plant to deliver water to Lake Mead or somewhere else along the Colorado River to supply the resource to whatever kind of population centers exist in the area at that time.

Beyond that, who knows what sort of technologies may exist in the not too distant future that allow for more reuse of water supplies designed for desert communities that rely on groundwater (astronauts drink recycled urine and live to tell about it). Also the consideration of other technology improvements in solar power generating that may make the ones proposed here obsolete. Google search the term 'singularity' and be ready to be blown away about reports of our civilization harnessing all of the available energy on this planet by mid century (yes, this century) and perhaps all of the suns energy a century or so after that. Whether you can wrap your head around that or not, we here in Kingman would be better off thinking 97 years down the road instead of thinking back 97 years. We haven't seen anything yet.

I sorta went off on a tangent there so I'm bringing back to what we know about water in Mohave County according the USGS and ADWR from their report written in March of 2006.

13,000,000 (million) acre feet of water.

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