Eye On Modesto

Thoughts and observations about Modesto and Stanislaus County

Archive for the tag “Water table”

VANCE KENNEDY AT MID ON SEPTEMBER 17, 2013

Vance C. Kennedy

Since the last MID Board meeting a lawyer friend of mine was kind enough to call my attention to a report, published in 2011,

English: 1. Aquifer 2. Aquitard 3. Unsaturated...

which is applicable to the question of what can be done about the grossly over-drafting of the water table in the foothills.  I have left a partial copy of the reference with Pat, your secretary.

I quote, “The common law doctrine of correlative rights regulates the taking and use of groundwater, unless local arrangements apply.  That doctrine limits groundwater pumping to the ‘safe yield’, being the volume of natural and artificial recharge of the aquifer, which is shared by overlying landowners on an “equitable basis” (regardless of their particular uses), and by non-overlying landowners, if there is sufficient water available.”

That last “if there is sufficient water available” is the key.  There is not sufficient water available to support the water drawn by the existing and proposed deep wells.  The rainfall in the foot hills averages in the range 12 to 14 inches of water per year, of which perhaps half contributes to groundwater.  Almond trees being planted require at least 30 inches of water per year, so there is a shortage of about 24 inches of water above the safe yield.   The shortage is being made up by mining ancient groundwater (2,000 to 13,000 years old) in direct conflict with the doctrine of safe yield.  It causes major and continuing drops in the regional water table.  The result is a short time benefit to the County of a large increase in almond production and a long term societal disaster for the foothills region.  Politically, it is a “hot potato”, but must not be ignored, as in the past.  Irreplaceable and extensive damage has already occurred and must not continue.

In sedimentary rock deposits it is well known that the lateral permeability of rocks is much greater than the vertical permeability.  Therefore, when a deep well operates, it can draw water much more easily from the side than above.  That water comes from the neighbors before it comes from the overlying rock.  California is one of two states that have no groundwater laws, but tort law may very well apply, since a neighbor’s property may become worthless as a result of the almond grower’s actions.  After all, if water is too deep or expensive to pump, a foothill house and land is worthless.  It no longer provides taxes to the County or a livelihood to people.

Who is responsible for filing the lawsuit to recover damages due to these deep high-volume wells?  It’s a valid question.  It is my non-lawyer understanding that if the problem is a purely local one, the affected property owner is responsible for handling the suit, but if it is a regional problem, the public authorities have the responsibility.  There is little doubt that this is a regional problem and therefore the County should file suit to stop the pumping and reimburse the harmed property owners.  There is some discussion of this question in the reference mentioned.

I realize that this is outside the sphere of influence of MID, but I thought the MID members might be interested.

A copy of this talk will be provided to the Board of Supervisors, and, as a water agency, you might be interested in following up on the information I have provided.

Part four in the applicable section: UncommonInnovation

Advertisements

Groundwater Problems In The Foothills of Stanislaus County

come on in, the water's bad

come on in, the water’s bad (Photo credit: scpgt)

By Vance Kennedy

There has been a large increase in planting of trees in the foothills of this county, especially almonds.  There is no flood irrigation to replenish groundwater, which is being pumped by increasingly deep wells.  Rainfall in the area ranges between 12 and about 16 inches per year on average, of which perhaps half recharges groundwater.

Almond trees need about 30 inches of water per year to do well.  Hence, there is on the order of two feet of water deficiency from rainfall alone.  The rest of the needed water must come from pumped groundwater.  That seems fine if you have a ready and easily available groundwater supply.  But therein lies the problem.

In the foothills the rocks are tight and much of the water must come from fractures.  Overall, an estimate of 10 percent porosity is possibly a generous estimate.  So, when one pumps out a foot of water, the water table drops 10 feet.  Since perhaps 2 feet of water must be pumped a year, that means that the water table may drop 20 feet per year or more.  Initially, the trees may do fine and the orchard can be sold to an unsophisticated buyer at a very large profit.  However, in 10 years, the water table will be down about 200 feet, or much more if the porosity is less than 10 percent.  I have heard that some very large pumps are getting water at 300 to 400 feet.  That is very expensive and cannot be justified if prices go down.  One might say that the buyer will lose and that is his problem.  There is a Latin phrase to describe the situation – Caveat Emptor – let the buyer beware.  It is not that simple.

When a well begins removing water from an aquifer, that is a water-bearing rock, there is a “cone of depression” that forms around the well, so that there is a sloping water table toward the well.  As the well goes deeper that cone of depression extends further and further from the well and ultimately will start drawing water from neighboring properties, causing their water table to drop.  California law provides no protection for that adjacent property owner.  He can be ruined, and he has no legal recourse.

There is another problem, for society as a whole.  When the tree grower has removed the groundwater to 400 feet or so and lets his trees die, that property is useless for many decades.  The water table will only be recharged by rainfall and that can raise the water table perhaps 5 feet per year.  That almond grower has literally mined a valuable resources and harmed future generations.  He has actually caused an environmental disaster, and as matters stand, there is no way of stopping him.

Mr. Kennedy is a citrus grower and a retired Hydrologist with the U.S.G.S.

 

Post Navigation