BOARD00330

• Board Meeting Date: 3/27/1968
• Description: Agenda or Table of Contents, Minutes, Memos
• Board Meetings - Doc Type: Meeting

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MR. CORNELIUS:

MR. MOULDER:

MR. CORNELIUS:

Now, when we plug in this second part, as
soon as we have the data, which is the artesian
aquifer, which we know leaks upward and con-
tributes water to the shallow aquifer system,
it is going to be somewhat less. How much
less I couldn't even guess right now."

"With t'1e artesian system there, the
tendency has been in the past few years to
withdraw this with the pumps in addition to
the normal flow. In talk~ng with Phil Emery
he was somewhat concerned that there might,
in future years, be a problem of subsidence
and he suggested the possibility, at a nomi-
nal cost, of putting in a subsidence recorder.
Could I have your views on that?"

"I think this is probably a good sugges-
tion. We found in most artesian basins
throughout the world where there are sub-
stantial ground water withdrawals from an
artesian system, that there is indeed an
accompanying subsidence of the land surface.
We have observed this in the Denver area
where the water pressures have dropped some
600 feet historically, it has been accompanied
by a decline in the subsidence of the land
surface. It has not been serious in the
Denver basin because of the structure of the
rocks in this particular area, but a similar
decline in the Long Beach area and the Houston
area and a variety of other places have caused
substantial declines, or substantial subsi-
dence. Where it coincides with a metropoli-
tan area or some other area where slopes and
differential settling is a significant aspect
then the problem is serious.

I'm not sure what would happen in the
San Luis Valley; I'm not sure what the
damages might be; but I think that it is
worth while getting some kind of data on that
particular subject."

"Because this could forecast the possi-
bility of subsidence, that's the way I
understand it."