Title: Chief Hydrologist. The challenge of supplying water
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Permanent Link: http://ufdc.ufl.edu/UF00051603/00001
 Material Information
Title: Chief Hydrologist. The challenge of supplying water
Alternate Title: Chief Hydrologist. "The challenge of supplying water to a population that is expected to double in 15 years. (April 1970)
Physical Description: 2p.
Language: English
Spatial Coverage: North America -- United States of America -- Florida
General Note: Box 3, Folder 5A ( WATER SHORTAGE, VOL. I. B3F5 ), Item 12
Funding: Digitized by the Legal Technology Institute in the Levin College of Law at the University of Florida.
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Bibliographic ID: UF00051603
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: Levin College of Law, University of Florida
Rights Management: All rights reserved by the source institution and holding location.

Full Text


In the March issue of "The Hydroscope", we discussecf'he water supply problems
of the District and presented a simplified water-budget to show how much water
we have to work with. Hiow can we rectify the challenging situation of having to
supply water to meet a population that is expected to double by 1985 which would
demand more water than nature supplies annually, and could we live w within our
water-budget? In our discussion today, I hope to answer these questions, at least
in a preliminary sort of way, recognizing that the dlta we have at hand are not
precise enough to give us definite answers, but only to indicate what we might do
in order to successfully meet these challenging problems.

There is little w., can do to augment nature's annual supply of new water to the
District. We might possibly add an additional 10 to 15% by means of cloud seed-
ing techniques. Research in the Everglades area of Florida recently has shown
co.sid.'abl-e success v s-in. ,lcltd t2. ,rst"'r clouds, and this tech-.
nique may offer us some hope of increasing our 53 inches of normal rainfall to
perhaps as much as 60 inches. However, more research must be done before we
can count on this as a certainty.

Other possibilities are:

1. Reuse of water. Most of the water that is withdrawn in the District now
is used once and then discharged to run off to the Gulf or the Atlantic
Ocean. If instead of single use the water were reused many times until
it finally gets to the point where it is no longer economically possible to
*reuse it, we might extend the water available for our use to the point
where a population of several times the size expected in 1985 could be
served. -

The reuse of water we have been talking about is particularly applicable
to the downstream cities and would ieqcuire that the used water be cleaned
up fit for human consumption then pumped inland and recharged to our
aquifers and streams by standard engineering practices. However, this
would cost money which we are not now either used to paying or perhaps
even willing to pay.

2. We can stop wasting water. Within the District, it is believed, there are
perhaps several thousand artesian wells flowing to waste. These wells,
Which serve no beneficial use, should be plugged and capped to stop this
needless drain on our gro un!d-water. Industry and agriculture could help
by using only the water that.is actually needed for their processes, and
in many industrial operations the water can be cleaned up and used again
and again. Even in our own households by careful use of water great
savings could be rnade. Some people, for example, will use 5 gallons
of water to flush a cigarette down a toilet bowl. Of itself this is only a
small quantity of water, but multiplied thousands of times it could amount
to a largC waste.

3. Currently it app'-ars that we lose about 36 inches out of our annual 53
inches of rainfall directly by. evapotranspiration. There are several
ways this loss can be cut down. One of the simplest is to lower the water
surface below the land surface in siwampy areas. The location of well
fields in such areas would lower the water level, remove it from the di-
rect effects of evapotranspir;ation and, thus, mnlke more v.'ater available
for our total use. On small lakes and ponds it has been shown that the

use of such materials as hexadccanol (a fatty alcohol) can be spread in a
thin layer to cut down water losses from 15 to 30'%o. Plastic film layers
have been float ted on ponds and small lakes, especially in the west, and
have been quite, effective in cutting down these losses. Perhaps a day
will be reached when nonbeneficial vegetation that grows around in lakes,
marshes and swampy areas can be replaced with more useful forms of
vegetation. This method hIas gained widespread use in the more arid parts
:of our country where the relatively useless water loving plants known as
phreatophytes have been grubbed out or chemically removed and replaced
with useful plants such as alfalfa or citrus.

4. Another means of extending our water supply would be to desalinate salty
ground water. In some places in the world seawater, which is the only
water available, is being desalinated to supply drinking water for urban
populations. H-lowvever, it costs a great deal more to take salt out of such
salty water as seawater than from water that occurs in the aquifers all
along our coastal areas. Currently the cost of treating seawater may run
to several dollars per thousand gallons, while ground-water may be treated
for about 25< to S1. 00 per thousand gallons. if our researchers are suc-
cessful in their effort to develop cheap sources of energy from fast-breeder
nuclear reactors, costs are expected to drop to the vicinity of 20, to 303
-per thousand gallons. Currently there are two desalinization plants suc-
cessfully operating in Florida. The first at Key West obta ins water from
a well tapping, the Floridan aquifer and has been in operation since World
War II. The other at Siesta Key, near Sarasota, started operation in 1969.
It seems likely that this method will be widely used in the coastal areas
of the District to supply the rapidly growing urban coastal population cwith
much needed fresh water. If this were done, the coastal communities
could make lesser demands on water from inland sources and problems
such as St. Petersburg has been experiencing in developing its inland well
fields would be greatly alleviated.

5. An additional means of augmenting our fresh water supplies is simply by
protecting the fresh water in the coastal aquifers. This can be best
effected.by placing artificial water control structures (salt water barriers)
as far downstream in canals and other tidal streams as possible to pre-
vent salt water from spreading inland up such water courses, especially
during times of drought. Each channel, whether it be a stream or a canal,
that lacks a salt water barrier acts as an armn of the sea in transmitting
salt water inland. Where new canals are cut from the shore inland for
any purpose, whether it be for navigation or for drainage', if salt water
is not excluded from the inland reaches of these canals, salt.vwater seeps
out of the bottom and sides of the canals to contaminate the underlying
fresh water in the coastal aquifers. These open canals and other free
flowing channels that connect with salt water pose one of the most serious
threats to the safety of the aquifer supplies, especially in the area along
the coast which is growing so rapidly. Currently studies arc being made
by the Sltate D).Larntment of Natural Ratsourues, the U. S. GeologIcil Sur-
vey and the Southwest Florida Water Mana,,ement District to establish a
salt water barrier line along, the entire coastal area of the District. Once
this is dune and salt water ba.rricrs -re costLructed and operated in the
lower tidal ends of canals and other channels, we \will then be in a position
to protect the fresh \water from being destroyed by salt water encroa"ch;iment.

In summary the n, there is some hope that we ca;n aid our vatler supplies by the
use of cloudl seeding, and other more efficient practices.

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