Ground-Water Occurrence and Movement, 2006, and Water-Level Changes in the Detrital, Hulapai, and Sacramento Valley Basins, Mohave County, Arizona
... whew!! That is a long title to a report.
Donna was nice enough to give me a paper copy of this report last year at some point. It has been sitting in my office ever since. I have cracked it open a few times to give it a read, it can be interesting if you are into that sort of stuff -- or perhaps if you are 'enlightened' (and sadly I am not according to the water worry warts). For the most part, I'm not into that report. I admit that I have very limited knowledge of water; where it comes from and how it ends up falling from my incredibly luxurious shower head.
However, I checked out the link that Donna left in the comments. And online, there is data to be found in the Appendixes. See this link for the list of the various ways that you too can view the data. I obviously clicked on the .xls link to open a spread sheet because I just love me some data in the afternoon, especially data that deals with 'net water level change' that was reported on 208 wells found in Mohave County in the three aquifers referred to in the long title of the document.
Oh you should see the data in all its glory. But click on that (appendix #2) for yourself. I'll need you to check my math... and folks that is all I'm providing in this blog post. Just some math. I do not pretend to be 'enlightened' about all things water... I certainly did not attend college to get a degree in hydrology (more like booze, babes, and parties -- no wonder I didn't finish)... all I'm doing is mining the data... and please check my math (as you now know what I was up to in my learning years).
Before moving on to the data, I have been told something about this report (that you can read online). According to the source of the information... the data in this report IS the data that will come out in the final USGS report sometime in 2010. The same report that some water worry warts say that we should wait on before we allow for more growth opportunities to flourish here in this community. Now I can't corroborate on this. I frankly do not know if this is the data that will be used in this long awaited for USGS report or not... really I don't. And I'm not here to say that it is. But it is a report offered by the USGS and it was prepared in cooperation with the Arizona Department of Water Resources (ADWR).
All I know is that the report was done by these government agencies and that they were nice enough to include an .xls link to a spread sheet with the data they reported on. It is this data that I will focus on in this post.
So are you ready?? (Dang, you could have read the whole USGS report by now instead of reading the lead up to the data findings that I'm about to share)
As I mentioned earlier, this USGS report has data on 208 existing wells, all within the three aquifers in Mohave County. The average water level change for all 208 wells shows an average loss of 1.75 feet from the time the water level of each well was originally read through to sometime in the year 2006.
Oh... you just know I'm not going to stop there. Much more breaking down of the data to do. But I'm starting with the overall figures for all of the 208 wells in the report.
Did you know of the 208 wells that 113 of them have actually had an increase in water level?? That is right, more than half of the wells studied have increased in water levels since they were first read and records kept. Before we start to party, 90 wells have decreased in water level. The remaining 5 recorded no change.
The figures for the 5 wells that saw the biggest drop in water level from the beginning of records through to 2006 were as follows; 134.8 feet, 69.9 feet, 66.7 feet, 55.7 feet, 52.7 feet. Now the figures for the 5 wells that saw the biggest increase in water level were as follows; 107.8 feet, 48.8 feet, 47.8 feet, 43.7 feet, 41.1 feet. The median figure for all 208 wells showed an increase of .4 feet.
As I moved along with my handy dandy data and spreadsheet, I saw the need to break out information from each aquifer... and I will do that below. But keep in mind something else and that is the element of time. You see not all of these water levels were originally recorded in the same year. Recording first started on 28 wells in 1963 through 1965 (according to the data). In 1978 through 1980 another 64 wells had their water levels first recorded. Then in 1995 and 1996 the government found the time to record the water levels in 116 additional wells (if you are checking my math at home, 28 + 64 + 116 = 208, right??). So yeah, of course I needed to break out the data further... and I will... but the following data is an overall look at the wells in each of the three aquifers according to the USGS report.
In the Hualapai Valley aquifer there are 100 wells. Measured in feet, the average net water level change shows a negative 5.41 feet per well.
There are 17 wells in the Detrital Valley aquifer and the average net water level changes shows a negative 4.22 feet per well.
Again folks, I'm doing averages here.
Now in the Sacramento Valley aquifer there are 91 wells and I found that the net water level change actually showed an increase of 2.73 feet per well. Yep, that is right, an increase in the average water level. How about that?? In a desert no less. A desert in a drought.
Math check... 100 + 17 + 91 = 208 right??
I could stop right here but the element of time had me intrigued to see what the averages might show over the varying lengths of time. The net water level changes (NWLC) for the wells originally recorded around 1964 (42 years) show an average loss in each well of 1.6 feet. The NWLC for the wells originally recorded around 1980 (26 years) show an average loss in each well of 0.8 feet. The NWLC for the wells originally recorded around 1996 (10 years) show an average loss in each well of 2.3 feet.
Now for the fun stuff, I'll be breaking the data down by year and by aquifer... this will be fun I promise.
I'll start with the Detrital Valley aquifer. It has the least amount of wells and there were only two time frames where original recording of water levels were done (three in each of the other aquifers).
There was one well that had an original recording from the 1964 era. That well has since increase its NWLC by 6.2 feet... an average annual increase of 0.148 feet a year. (Doing the math at home?? I divided the 6.2 figure by 42 years and I will use 42 years for all the of the 1964 era original water level recordings from here on out... 26 for the 1980 era water level recordings... and 10 for the 1996 era water level recordings). The other 16 wells showed an average drop in NWLC of 4.875 feet per well... an average decrease of 0.488 feet per well per year.
Still following?? Still two more aquifers to go.
Now we'll tackle the Sacramento Valley aquifer. There are 16 wells in that aquifer that recorded the original water level from the 1964 era. The average NWLC shows a decrease of 0.9 feet per well... an average decrease of 0.02 feet per year. There are 30 wells in this aquifer that first recorded water level in the 1980 era. The average NWLC for these wells shows an increase of 6.9 feet per well... an average increase of 0.265 feet per year. There are 45 wells in the aquifer that recorded water level in the 1995 era. The average NWLC for these wells shows an increase of 1.232 feet per well... an average increase of .123 feet per year.
One more to go... at a later time I may put together a table for easier viewing but don't have the time for that right now.
Last up is the Hualapai Valley aquifer. There are 11 wells in this aquifer that first recorded water level in the 1964 era. The average NWLC shows a decrease of 3.5 feet per well... an average decrease of 0.082 feet per year. There are 34 wells in the aquifer that first recorded water level in the 1980 era. The average NWLC shows a decrease of 7.6 feet per well... an average decrease of 0.294 per year. There are 55 wells in the aquifer that first recorded water level in the 1996 era. The average NWLC shows a decrease of 4.435 feet per well... an average decrease of 0.443 per year.
And there you go. Just the data and nothing but the data. Like I said earlier, I may put together a table that makes it easier to read the data that I broke out. Just don't have the time at the moment.
Draw you own conclusions and share them in the comments. Would love to see some input from the water worry warts as well. What does this data mean?? Your turn.
Post updated for data tables...
Data tables for applicable data used in this blog post.
|Era||1964 ||1980||1996 |
|Total Number of Wells ||28||64||116 |
|NWLC ||-1.6||-0.8||-2.297 |
|NWLC average per year||-0.039||-0.032||-0.230|
|Aquifer Location ||Hualapai Valley ||Sacramento Valley||Detrital Valley |
|Total Number of Wells ||100||91||17 |
|NWLC ||-5.41||+2.73||-4.22 |
|Aquifer Location ||Hualapai Valley ||Sacramento Valley||Detrital Valley |
|1964 Era Wells ||11||16||1 |
|NWLC average per year ||-0.082||-0.020||+0.148|
|1980 Era Wells||34||30||N/A|
|NWLC average per year||-0.294||+0.265||N/A|
|1996 Era Wells||55||45||16|
|NWLC average per year||-0.443||+0.123||-0.487|