The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1906-02-03
GETS WATER FROM
THE SAND DUNES
knowledge of How the Supply Is OBJ
tanned Matter of General
Interest.
1T is FILTERED, OF COURSE
AMSTERDAM OWNS ITS WATER
WORKS.

That Amsterdam, like several other
cities of Holland, derives its water from
the sand Dunes" is fact pretty wide
ly known, but it is possible that
knowledge of just how the supply is
secured may not be quite so general,
says the Engineering News. The
dunes are irregular round-topped
sand hills, which have been erected by
wave and wind action along the whole
of the Netherlands coast. In height
they at times reach 100 feet, but aver
age much less, while the breadth of the
range is very variable. Near the sea
they are devoid of vegetation, the sur
face of the sand being moved to a con-
siderable degree by the action of the
wind, while further inland grass ap-
pears and crops of various kinds are
raised. This particular section, near
HARLEM, whence Amsterdam draws it's
water, is composed of rather lose
sand in which the reed grass plant
ed in tufts by the city water depart
ment, keeps a very precarious footing.
The rain falling thereupon each year
amounts to about twenty-efsht inches.
The natural ''run-off'' of the dunes"
is nearly zero, and the absorption by
vegetation still less; "a per cent of the
annual rainfall sinks in the sand. 1t is
interesting to note that according to
the opinion of some writers the water
bearing zone of the dunes is fed in
part by the condensation of the
aqueous vapor contained in the air
which circulates through the spaces be-
tween the sand grains, and also in part
by ground water which flows from the
interior of the country toward to sea
and which rises in the sands Of the
dunes partly by capillarfty and part
ly because of the pressure of the spe-
officially heavier sea water below. One
theory advanced to account for the
ground water of the Netherlands coast.
and of the islands adjacent thereto, is
that such water might be considered
fossil in character it haYin9 saturat-
ed the strata previous to the sinking of
that section Of the continent. Possibly
it may at that remote time have been
in the state of ice, and have sunk as
such with the sinking strata.
According to the views of Mr.. Andri-
ment, the greater part Of these waters
come by subterranean flow from the
! interior Of the country. This prOpO-
! sition is combated by Mr.. Pennik, who
shows by careful measurements that
| the water of the dunes" has it's origin
/ in the local rainfall Entirely in &C
| cordance with the view that local rain
! fall alone is responsible for the dune"
water is the fact that upon sandy islets
! of the sea at long distances from shore
| ordinary Imestic wells furnish sup
/ plies of very acceptable character. The
area drained by the collecting system
/ of Amsterdam is about $500 acres and
/ the volume of water secured amounts
/ to some 100000 gallons daily. Open
! canals, very similar to small railway
cuts, wind between the sand hills and
gather the ground water of the dis
! trict into a collecting basin, whence 1t
| is pumped to Amsterdam, some four
teen miles away. The depth Of water
/ carried in them is now about six feet.
! The aggregate length of the canal is
/ about sixteen miles.
The general level of the local water
| table has been lowered from twelve
to fifteen feet since 1853 by the opera
ton of the Amsterdam water system,
the case being similar to what has been
observed IN the chalk wells of Lon
don, namely, more water has been re-
moved than could be replaced by the
annual rainfall. Now, however, the de-
| livery is fixed at a figure not to eX-
! ceed the rainfall, and consequently the
| level of the water table is held con-
slant. The dune" supply allows about
fifty liters per capita per day Q3.29
! gallons) to the inhabitants of Amster-
| dam, an amount which is recognized
| as insufficient, and steps are being
taken to increase the quantity. Be
fore the delivery to the consumer the
water is filtered through English
| sandbeds of the ordinary type. They
/ are uncovered and have vertical walls
of brick with asphalt bottoms. The
depth of the sand is thirty-twO inches
Originally the works were controlled
| by a private company, but they were