• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Skip to footer

The Valley Citizen

Nature, Environment, History & Politics

The Valley Citizen

  • Arts
  • Education
  • Environment
  • History
  • Nature
  • Politics
  • Wit
  • About
  • RSS Icon

Dr. Kennedy’s Groundwater Fact List

July 14, 2014 By Eric Caine 3 Comments

Dr. Vance Kennedy
Dr. Vance Kennedy

The groundwater crisis in the San Joaquin Valley is especially critical. In Stanislaus County, tens of thousands of acres of new almond orchards have put a tremendous demand on groundwater, causing concern for the future of the aquifer. Many residential wells have run dry, yet thus far county supervisors have failed to take action.

On June 28, Stanislaus County Supervisor Terry Withrow was quoted as saying, “We’ve got to stick with the science and get past the emotions.” We agree. Therefore, The Valley Citizen will be publishing a series of articles based on the science of groundwater and groundwater use in the northern San Joaquin Valley.

Dr. Vance Kennedy has a PhD in Hydrology. He is retired from the United States Geological Survey. While at the USGS, Dr. Kennedy received the Distinguished Service Award, the highest possible such award bestowed by the Department of Interior. At the age of 91, Dr. Kennedy still farms eight acres of citrus north of Modesto. Here is Dr. Kennedy’s list of facts about groundwater in Stanislaus County, especially the eastern portion:

  1. Geology in the valley and foothills is composed of alternating layers of shale, sand, and gravel.
  2. Shale is virtually impermeable in either the vertical or horizontal direction. Hence, it acts as a major barrier to vertical movement of groundwater in the geologic column. However, shale occurs as localized lenses, except in the case of the Corcoran clay, which extends westward from about the middle of Modesto.
  3. Sediments are laid down in essentially horizontal layers with inter-fingering shale, silt, sand and gravels.
  4. Horizontal permeability or the sediment layers varies widely, with clean gravels thousands of times more permeable than silts.
  5. The overall effect of these facts is that the horizontal permeability of a rock column is commonly 10 to 100 times that of the vertical permeability.
  6. In the case of a deep well tapping into a widespread permeable aquifer, the water removed will easily come from thousands of feet around the well.
  7. The shale layers will cause a zigzag vertical movement of water downward to replace the water removed by the deep well. That movement can be slow, but it must happen because of the required mass balance. In other words, there won’t be big open holes where the water was removed.
  8. There has been much talk about “confined” aquifers as though they have no connection with the water above them and that one can remove water from them with little or no effect on shallow aquifers. Physically, THAT WATER MUST BE REPLACED (caps are Dr. Kennedy’s) or the sediments will shrink, causing subsidence. There is no “free lunch.”
  9. Conversations with some other professional hydrologists indicate that east of the Corcoran clay there may be “semi-confined” aquifers in the sense that vertical water movement is very slow, so most replacement of well water must come laterally.

Summary:

There are no extensive clay layers acting as a seal between shallow and deep aquifers east of middle Modesto. Hence, water removed from deep aquifers must inevitably affect shallow aquifers and, therefore, streams and reservoirs.

Both drought and large deep wells account for drying up of shallow wells, with responsibility varying with the area and amount of water from large deep wells. That responsibility can only be determined if volumes of water being removed by wells is open information.

The Stanislaus County Board of Supervisors can and should require information publicized on large well production by anyone. The argument from one official against publication is that it will encourage lawsuits. That won’t happen unless there is reason to believe that what is being done is illegal. Do the Supervisors want to permit illegal actions?

 

 

Filed Under: Environment, Featured Tagged With: Almond Orchards eastern Stanislaus County, San Joaquin Valley groundwater, Stanislaus County groundwater

Reader Interactions

Comments

  1. John Wagner says

    July 15, 2014 at 3:50 pm

    An interesting article, although Dr. Kennedy’s fairly technical review makes it a bit hard for a layman to grasp the subtleties. However, your summary is most helpful.

    Can anyone define “deep wells” and “shallow wells” and estimate the amount of the water use from each in the area? If Big Ag is pumping huge volumes from deep wells and, as Dr. Kennedy says, the water available in shallow wells will ultimately trickle down to refill the deeper aquifers, it almost looks like the likely incidence of shallow wells going dry could be estimated over time in some areas. Maybe providing a dry well forecast could help the soon-to-be-waterless get some action from the politicos.

    Reply
  2. Eric Caine says

    July 15, 2014 at 4:00 pm

    The summary is Dr. Kennedy’s. We’ll be following up with more science and some definitions. As I understand it, shallow wells are usually residential and depth depends on the water table. Most around here are well under 100 feet. The dry well forecast is “now,” as more go out everyday; again, most are residential.

    Reply
  3. Bruce Frohman says

    July 20, 2014 at 3:19 pm

    I would presume that a shallow well is a well in the upper layers of valley sediment, above the highest level of impermeable shale. A deep well would be one drilled below the first level of impermeable shale.
    A friend of mine in Madera County told me that when his shallow well went dry last year, he had a deep well drilled. He told me that a hydrologist predicted that his new deep well will go dry within 5 years.
    This illustrates how rapidly we are presently depleting ground water resources.

    Reply

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Note: Some comments may be held for moderation.

Primary Sidebar

Off The Wire

Mike Pence Can?t Walk Away from the Big Lie - The Bulwark
Mike Pence Can’t Walk Away from the Big Lie – The Bulwark
Targeted on Jan. 6 for saying the election was valid, he now plays footsie with the conspiracy theorists. It’s in keeping with his character.
thebulwark.com
On Voting Rights, GOP Lawyers Say the Quiet Part Out Loud - The Bulwark
On Voting Rights, GOP Lawyers Say the Quiet Part Out Loud – The Bulwark
Arguing before the Supreme Court, they admit their case isn’t about principle or election integrity, it’s just about winning.
thebulwark.com
Could Biden Be the Most Transformative President in Living Memory? - LA Progressive
Could Biden Be the Most Transformative President in Living Memory? – LA Progressive
Most Transformative President – Biden has the chance to lead a green and digital recovery that would create millions of good jobs.
www.laprogressive.com
Louis DeJoy Is Killing It
Louis DeJoy Is Killing It
While Biden dithers, Trump’s minion wrecks the postal service.
nymag.com
So What if Romney Doesn?t Solve the ?Root Causes? of Poverty?
So What if Romney Doesn’t Solve the Root Causes of Poverty?
We handle problems all the time without dealing with their root causes.
nymag.com
The Facts of Life - The Bulwark
The Facts of Life – The Bulwark
My suggestion last week that perhaps the best way some of us who’ve been conservatives can now help the country is to help the Biden administration succeed, and help the Democratic party move to the center, seems to have stirred up a minor tempest in the conservative teapot. I asked whether one shouldn’t consider allying…
thebulwark.com
WSJ News Exclusive | Texas Electric Bills Were $28 Billion Higher Under Deregulation
WSJ News Exclusive | Texas Electric Bills Were $28 Billion Higher Under Deregulation
Texas’s deregulated electricity market left millions in the dark last week. For the past 20 years, its consumers have paid more for their electricity than state residents who are served by traditional utilities, a WSJ investigation found.
www.wsj.com
The making of Madison Cawthorn: How falsehoods helped propel the career of a new pro-Trump star of the far right
The making of Madison Cawthorn: How falsehoods helped propel the career of a new pro-Trump star of the far right
Cawthorn has emerged as one of the most visible figures among newly arrived House Republicans, who have promoted baseless assertions and pushed a radicalized ideology that has become a driving force in the GOP.
www.washingtonpost.com
Los Angeles Just Opened a Tiny Home Village for the Homeless
Los Angeles Just Opened a Tiny Home Village for the Homeless
The colorful community was built in just 13 weeks!
www.housebeautiful.com
California's coronavirus strain looks increasingly dangerous: 'The devil is already here'
California’s coronavirus strain looks increasingly dangerous: ‘The devil is already here’
California’s coronavirus strain is more transmissible than its predecessors, is more resistant to vaccines and may cause more severe cases of COVID-19.
www.latimes.com
More Than 150 Biz Leaders Endorse Biden's Sweeping COVID Package
More Than 150 Biz Leaders Endorse Biden’s Sweeping COVID Package
More than 150 business leaders from various industries have signed a letter backing President Joe Biden’s $1.9 trillion COVID-19 relief…
talkingpointsmemo.com
Exclusive: Defeated and impeached, Trump still commands the loyalty of the GOP's voters
Exclusive: Defeated and impeached, Trump still commands the loyalty of the GOP’s voters
www.usatoday.com

Find us on Facebook

The Valley Citizen
PO Box 156
Downtown Bear Postal
1509 K Street
Modesto, CA 95354

Email us at:
thevalleycitizen@sbcglobal.net

Footer

The Valley Citizen
PO Box 156
Downtown Bear Postal
1509 K Street
Modesto, CA 95354

Email us at:
thevalleycitizen@sbcglobal.net

Subscribe for Free

* indicates required

Search

• Privacy Policy

Copyright © 2021 The Valley Citizen

Dedicated to the memory of John Michael Flint. Contact us at thevalleycitizen@sbcglobal.net

Editor and publisher: Eric Caine

Website customization and maintenance by Susan Henley Design