'File 19/252 Bahrain Water Supply' [‎9r] (19/96)

i
Beneath Zone "A" and separated from it by 25 to 50
feet of clay, lies Water Zone "B". This Zone "B" occurs
within a limestone body 100 to 150 feet thick and as the
available evidence indicates that the source, or at least
the chief source of water in this zone, is the upper 40 feet
of the body, it is this portion with which we are primarily
concerned.
Beneath the limestone body in which Zone "B n is found,
is a third limestone series, the two being separated by a
shale interval of slightly more than 30 feet. The upper 50
feet or so of this third limestone body is the portion we
are interested in, and it will be known as Water Zone M E n .
Areal Extent
There is a belt at a low elevation around the outer
edge of the island within which (with the possible exception
of a strip along the southeastern shore) it is possible to
obtain water from at least a portion of the three zones
described in this report. How far inland this belt extends
is not known exactly, although it is probable that the
series of springs and shallow wells which irrigate the date
gardens farthest inland define roughly its innermost edge.
The information now available does not permit determination
as to whether this edge is limited by the water head or by
the pinching out of the individual water bearing horizons.
Water Zone "A "
Within the limestone |)ody which has been designated
as Zone "A", there are ordinarily two producing intervals,
although where this section is thin, as at Zellaq, there
may be only one, and at Umm Sabaan where the section is
thick, we have three such intervals. These are waters of
low static head and they do not always rlow. Since the
deeper /-