Transboundary Groundwater?

The U.S. Supreme Court has recently taken on the lawsuit Mississippi filed first against Memphis Light, Gas and Water, and later the state of Tennessee, over Memphis' pumping of groundwater from the Sparta Aquifer - a very prolific fresh water aquifer underlying both states.  Some are calling this the first transboundary groundwater case in the US.  Anyway, Mississippipi is claiming that as much as 30% of the water Memphis has been pumping for many years has been coming from under Mississippi, and that use of Mississippi groundwater is causing the state economic harm.  GMDA has covered this story and even captured some other coverages as well.  This will be an interesting court case, because as Michael Campana and others have already said, this will not be a small ruling - Mississippi is seeking a very large penalty.

Oops.  Did I miss this one!  My apologies.  All the above was true at one time, but as Jesse Richardson pointed out in a comment, I was in fact confused.  However, while the Supreme Court did effectively close Mississippi’s current claims over withdrawals from the aquifer back in 2010, they did so without prejudice, so Mississippi is still free to file an original action with the Supreme Court whenever they think they can sufficiently demonstrate injury.  The legal pundits are guessng that the two states will work out something by mutual agreement.  I'm betting this won't happen as amicably as the pundits are thinking it will.

Anyway, it still gets one to thinking about the nature and extent of transboundary groundwater, and whether or not the Ogallala might become the poster child for such legal actions.    I recall a Kansas Geological Survey study done a while back that quantified the impacts of northeast Colorado well production on the groundwater underflows crossing the state line into northwest Kansas.  Due to groundwater declines upgradient in Colorado caused by their pumping, the natural groundwater underflow into Kansas has been reduced.  Does this qualify for a lawsuit?   

There have to be scores of major and minor transboundary aquifers in the US, assuming an aquifer underlying two or more states qualifies as such.  Be advised that in the international community, a transboundary aquifer is only one that underlies two or more countries.  In their listing of the 274 known transboundary aquifers of the world, the Ogallala doesn't even show up.  In any case, another issue has to be the very wide range of influences caused by pumping centers likely to be present in any or all the states claiming damages.  This'll become a prior appropriation impairment call on steroids I'm afraid.  Oh well, it's a new day every day in groundwater - and thank you Jesse for such a diplomatic correction.