Can Flexibility Be Had Without Increasing Water Use?

Dilemma - Kansas irrigators are asking for multi-year flexibility under their annual water rights for various reasons.  They say it will help them make more efficient use of the water they pump, and provide an answer to staying within their legal rights in our state's exceptionally variable weather regime.  Is there a way to provide such flexibility without resulting in any increase in water use?

With an annual water right an irrigator might have 100 AF of water as his or her annual appropriation.  The way it was perfected means that the 100 AF would normally include enough water to cover a dry year, and as such, it would never be legally allowed to exceed 100 AF of use.  In a dry year they would likely use all of it, but in the average and wet years they would use less - say 75% in an average year and 50% in a wet year.  Under this arrangement, and never knowing beforehand if it was going to be dry, wet or average, water use would end up being 75% of the 3-year cumulative appropriation (225 AF) if it was an average 3-year pattern (one wet year, one dry and one average - in any order).  Since there would be an equal chance of having any combination of years (3 wet years in a row (resulting in 50% total use) or 3 dry years in a row (resulting is 100% use) or any other combination) it makes sense to me that over the long haul, the averages will hold true.

However, if you allow an irrigator to use 300 AF over every 3-year period, could they more consistently use their full 200 AF cumulative use in the first 2 years - regardless of the weather - and then play the averages in the third year?  The math says that if the third year was wet, the irrigator would use 250 AF cumulative; if it were average, they'd use 275 AF and if it was dry they'd use all 300 AF.  In every case you'll note they use more than the 225 AF they would have used under the annual water use system.  This begs for some kind of AF stipend from the irrigator for the ability to have the added flexibility (flexibility translated to:  management opportunity to maximize water use).  But what is a fair arrangement that will allow flexibility, but not increase water use?

Some systems I've looked at also provide for "borrowing" from or "carrying over" to the next 3-year allocation period.  While providing yet more flexibility, this arrangement also provides that much more management opportunity to maximize water use.  Maybe it's not that big of an issue.  While some increase in water use is possible with a multi-year appropriation, it's not all that alarming and the increased use is capped - meaning that once it starts occurring, it never gets any bigger.   But it does occur every 3 years.  Should we just chalk the likely increase up to the cost of doing business and take the extra production?

In Kansas we also have peripheral issues - the most pressing being possible impairment if we allow essentially uncontrolled annual pumpage. Our well spacing systems were mostly designed on annual maximum pumpage quantities so as to have a known impact on all surrounding wells.  Allowing any additional annual pumpage could theoretically pose short term supply problems between wells.

I'd be interested if anyone else has addressed this issue, how they have done it, and how satisfied they are with their approach.  Kansas will be thinking about this pretty seriously over the next 6-months or so.  We're always looking for ideas.