Friday, April 30, 2010

Groundwater as a Private Right

I can't resist this one.  As many know, Texas has long treated groundwater as a private right with their "Rule of Capture" which basically says anyone can use the water as much as they like - even to the detriment of others. It has often been called the "Rule of the Biggest Pump".  While it has certain advantages, it also guarantees that every drop of water can be used.

With a case now in the Texas Supreme Court (Edwards Aquifer Authority v. Day) the issue of who owns the water is expected to get more court direction when the ruling is released.  Mr. Day (who has incidently passed away) argues that the Edwards Aquifer Authority can't restrict him from using groundwater from under his land, while EAA argues that they have the right to manage the groundwater and his diversion will overtax the supply. 

I ran across a set of statements made by a Texas Association which I find interesting.  This group is asking the Texas Legislature (presumably anticipating a court decision to the contrary) to clearly make groundwater a private landowner right.  The statements are:

“Private landowner ownership of groundwater encourages good stewardship and promotes accountability.”

"Private ownership provides more certainty and balance in water planning for the future.”

“As the demand for groundwater in Texas increases, it is important that groundwater continues to be recognized and reaffirmed as vested, real property of private landowners.”

“... supports reasonable regulation of groundwater so private landowners are treated fairly and afforded due process, property rights are respected, and all private landowners maintain the ability to use groundwater for any beneficial use."

Inquiring minds are likely to wonder how unrestricted access to water by all landowners can provide more certainty in water planning, better accountability, and at the same time respect all property rights.

While this case is expected to make or break local groundwater management authority in Texas, I halfway expect the court to render a ruling that continues to leave wiggle room on each side of the issue.  This is the way Texans roll!

Thursday, April 22, 2010

"Time Running out for the Ogallala" Article

Dave Thier just posted an item on the Ogallala Aquifer that is the typical gloom and doom approach - the implication is that the entire Ogallala is doomed to go dry in 20 years or less.  The picture here is from the article, and is identified as being an irrigation system near Hoxie, KS - within our GMD here in NW Kansas. 

While not stated as such in this article, I wonder if the picture is presented by the author as an example of the wasteful irrigation methods being used that are the cause of the doom cited in the article.  This is usually the case in most pieces I read on this subject.  It could also be that Mr. Thier intended nothing more than to supply a striking picture of an irrigation system to add interest to his piece - it is a nice photo.  If this is the case then I apologize for overreacting.

In any event, this kind of irrigation in GMD 4 is rare - in fact, this is the only big gun system we staff at GMD 4 are aware of.  Secondly, this photo was taken along the tree-lined banks of the Solomon River East of Hoxie - the water source being the alluvial aquifer associated with the Solomon - not the Ogallala.  Thirdly, the irrigated fields in this area are very small and irregular and don't lend themselves to other more common irrigation systems.  And forthly (and finally) I must say again that inefficient irrigation is NOT the cause of the declines in any aquifer we have in NW Kansas.  It is the consumptive crop water use that occurs virtually equally under every irrigation system that is the cause.

Anyway, back to the reason for this blog.  While many areas of the Ogallala are declining faster than most would think prudent, this is not the case everywhere.  Our GMD average decline rate in the Ogallala for the past 30 years has been .6 feet per year.  The range is from 2 feet per year to areas that are increasing in saturated thickness.  We are in an area of the Ogallala that I think is on the low side of all the average statistics cited for the full aquifer - and certainly far better off than all the areas the press likes to focus on - these being the worst of the worst.

Anyway, it'd be refreshing if the press would spend a little more time characterizing the aquifer more accurately so that their readers get a truer sense of the situation.  Of course, in the end, it's usually a matter of reader perspective.  If you find any level of decline appalling, then our condition is also incredually unacceptable.  Comments?

Wednesday, April 21, 2010

Groundwater Folks Convene - GMDA

The Groundwater Management Districts Association (GMDA) will hold its Summer meeting in Little Rock, AR on June 6-8, 2010 at the Capital Hotel.  You are invited to attend and meet a lot of the groundwater folks from Nebraska, Kansas, Texas, Colorado, Mississippi and a smattering of other places where local GMDs exist.

During the session, which is refreshingly informal (and I mean this literally) each state will have a presentation on:  a) irrigation methods in their state; 2) how to be more efficient with irrigation; and 3) how conservation programs contribute to reducing groundwater use.  As an added bonus, Keith Admire from the NRCS National Water Management Center will also present.

There'll also be presentations from: Todd Fugitt, Arkansas Water Resources; Richard Coupe, USGS Groundwater Modeling; and the Corps of Engineers on the Lower Arkansas River.  Many don't realize the extent to which Arkansas irrigates from groundwater - it's an eye-popping irrigation state in terms of acres irrigated.

Contact (email) Judith McGaugh for more information.  Also consider visiting the GMDA Website for information on GMDA or this conference.

Looks like the YMD Joint Water Management District has put together another great session.  

Tuesday, April 20, 2010

One More Irrigation Efficiency Technical Point - Evaporation

Also in the irrigation efficiency debate, we must remember that evaporation is a consumptive water use (CU).  Normally crop water use (transpiration) and evaporation (from applying water and from leaf surfaces and soil) are lumped together because it is difficult to separately quantify the two values.  Together these values are called evapotranspiration, and again, are a consumptive water use.  However, of any evapotranspiration value used to descibe an irrigation water balance, transpiration is by far the larger portion of that value and can approach or even exceed 90%. 

Since irrigation efficiency improvements reduce non-consumptive water applications AND evaporation, most assume that these upgrades do in fact reduce CU and thus conserve water.  I have been called on this point before, and technically this is true enough.

However, most continue to deny that CU increases under most of these conversions and continue to point to the evaporation reductions.  Our findings show that CU increases do occur, and easily offset the evaporation reductions - resulting in a net increase of water use.  Normally CU will increase in one or more of three ways:  additional acres are irrigated; a higher water consumptive crop(s) is grown on the same acres; or more of the same crop is produced on the same acres - all made possible by the "saved" water resulting from the increased irrigation efficiency.

Now, to be perfectly honest, not every irrigation conversion to a higher efficiency system increases CU.  Some irrigators can't add acres, don't grow different crops, or don't manage to increase yields.  But most do.  So again, we find that the net change of a number of conversions is in fact an increase in CU.  While it's not an obscene increase (kinda subtle, actually) my point is that the amount of money applied to doing this in the name of "saving water" in water short areas is obscene - especially when it actually makes the problem just a tad worse.  The money can almost always be better spent on other solutions to reducing water use.

So wrapping up:  1) irrigation efficiency conversions can in the exact right hydrologic conditions conserve water, but these conditions don't exist very often (see April 19, 2010 blog); 2) they often reduce evaporation (consumptive) water losses, but these savings are small and are most often easily offset by practices that increase CU; and 3) the cost of this approach to "save water" is more often than not very poorly spent money.  Comments?

Monday, April 19, 2010

When Irrigation Efficiency Saves Water

I have been pretty critical of improving irrigation efficiencies as a means to conserve water.  There are a number of posts within this blog that deal with my concerns.  However, there are times and situations where this practice does in fact conserve, or save, water.  This is what this post is about.

In general, any situation where the irrigation water being applied is from a different source than where the inefficient water is collecting, AND, where no one is using the inefficient water losses, it is a very good idea to improve irrigation efficiencies - which simply eliminates the inefficient water sink that no one else is using.  (This is the "poor timing" water volume shown in the picture)  These efforts will save energy and other crop inputs, as well - all good things.  However, if someone else is using this source of water, all bets are off.

Another example that comes to mind is in a groundwater situation where there is a shallow, unusable aquifer perched above the irrigation water source, AND, all deep aquifer recharge is from lateral sources not connected to the perched aquifer.  In other words, the inefficient water use collects in the shallow, unused, perched aquifer and never returns to the original source.  Again, irrigation efficiency improvements under these conditions will clearly save water within the deep source aquifer.  But again, no one can be using (have rights to) the shallow water supply because the efficiency improvements, if taken far enough, are eventually going to eliminate its source.

In both of the cases just discussed, it should be noted that the consumptive crop water use does not change after the improvements - the crops continue to consume the same amount of water as before.  The savings come from the elimination of the inefficient water application that was not returning to the original source.  This is all water that, after the improvements, no longer needs to be pumped.  These situations extend the life of the original water source - which even I can define as conservation.

Other than these specific conditions, irrigation efficiency improvements do not conserve water much at all - certainly not enough to spend the amount of money folks are suggesting.  There are other benefits to increased irrigation efficiencies - like reduced energy and reduced crop inputs and a better farm operation bottom line.  Let's do it for these reasons, but be aware that consumptive water use is not being affected and it's the consumptive water use that changes aquifer storage volumes.  The fact that most argue these improvements also increase production per unit of pumped water probably tells us right off the bat that consumptive water use is increasing as a result - regardless of what pumped water is doing.

Before you buy into irrigation efficiency improvements, make sure you understand what problem it is you're trying to impact, what benefits these efforts will have, and at what cost.

Wednesday, April 14, 2010

Groundwater Monitoring

I need help with the science of groundwater monitoring. Our existing observation well network consists of 287 (or so) wells that are spacially located across the district via a 6.25 mile hexagonal grid.  Statistical work said this spacing and configuration would give us an acceptable accuracy to describe the water table attitude with the least number of wells to be measured. 

Subsequent statistical analysis confirms that the current network is in fact satisfactory enough to determine, over longer time frames, the areas of the district where water level changes are relatively worse than, or better than, average.  However, it is NOT sufficient enough to monitor the water levels in smaller areas, or for shorter  time frames - which is what we need now in the designated high priority areas.

How then is the best way to improve the accuracy of these smaller observation well networks?  Is it simply a matter of density?  The pundits tell us that all else being equal and with our variability in our aquifer bedrock, it takes approximately 4 times the well density to double our statistical accuracy.  Do we use data loggers or continue with annual tape measurements?

Would an index well (or two or three) be a better approach?  Theoretically, once the index well is data logged, corrected for barometric influences and has a recovery curve applied so that its full recovery level can be ascertained, just a few of these could more accurately reflect what is actually going on in these smaller areas from year to year - and maybe even one if we choose wisely.  But then we have the issue in the short term of comparing new, corrected and massaged data with the existing unmassaged data.  And the water users are not keen on one index well replacing the 9 obs we currently have in this specific area.

I'd be interested in hearing from the science community on any other approaches that would be available for consideration - preferably other approaches that have worked in other places.

Friday, April 9, 2010

The Other Aspects of Conservation

Water conservation is pretty well supported and many people are working to make better use of water where supplies are limited.  Government programs are pouring millions of dollars into water use efficiency improvements - including the irrigated ag sectors.  It comes as little surprise to me that my efforts have been coming up seriously short to convince programs that irrigation efficiency improvements don't really conserve water very much at all - as this position is counter-intuitive at best.  Maybe I'm simply not articulate enough.

However, the fact that these efforts have been going on in areas that have not yet prevented new water resources development remains astounding to me.  What good does it do in an area of limited supply to conserve water and then allow more to be developed for new uses?  Nothing is gained except the added social and economic stress that is going to make real conservation just that much more difficult a few years down the road.

In my mind, the Kansas Water Transition and Assistance Program (WTAP) had the perfect design.  It paid a direct incentive per acre-foot of consumptive water use to permanently retire the water right and convert the irrigated acres to dry land production.  It was only available in areas where no new water rights were available and was based on actual historic water use.  No paper water rights were involved.

The next program in any limited supply area that professes to be conserving water should be asked a few hard questions.  Ask if real or paper water is involved.  Ask if new water is available that will compromise any conservation gains.  Ask if pumped water or actual consumptive water use is being conserved.  Only when all three of these conditions are met is there any real water savings.