Overview of Middle East Water Resources
Groundwater Basin Summaries
![[small map]](images/p15_loc.gif)
Azraq Basin
 |
|
Well F3760, in the northwestern part of the basin, shows
construction characteristics for a typical well completed in
the Amman–Wadi Sir aquifer system. In this well, water-bearing
limestone and chert between 471 and 640 m
supply an average 15 liters per second (L/s). Water levels
in the well are about 210 m below land surface.
|
The Azraq Basin, located in the Jordan Plateau, is a
tectonic depression associated with the Wadi Sirhan
graben. The basin covers an area of about 12,220
square kilometers (km2) and is underlain by layers
of limestone interbedded with marl, sand, chalk,
chert, and sandstone that overlie granitic basement
rocks. Basaltic flows cover about one-third of the
total basin area.
Groundwater is recharged by precipitation at an
average volume of 24 MCM/yr, and flows generally
toward the center of the Wadi Sirhan graben.
Groundwater is the principal source of freshwater
in the basin and is supplied to wells and springs
by three principal aquifer systems:
- The Basalt–Rijam system, consisting of
basalt and limestone of geologic units Ba
and Ks;
- The Amman–Wadi Sir system, consisting of
limestone and chert of geologic unit Ks; and
- The Kurnub Sandstones of geologic unit Kk.
The Basalt–Rijam system is the main aquifer of
the Azraq Basin, supplying flow to many springs,
particularly in the villages of Shishan and Druze.
These springs discharge into marsh and swamp
areas, which serve as a natural reserve for migratory
birds. Due to the poor-to-bad water quality of
the Kurnub and Amman–Wadi Sir systems, the
 |
|
Groundwater levels in the Azraq Basin have
shown a long-term decline in response to pumpage.
Because recharge to the basin is about
24 MCM/yr and current groundwater pumpage
is about 50 MCM/yr, there is a net deficit that
results in water-level declines in wells.
Dissolved solids concentrations in the basin
generally have increased over the years. This
increase corresponds to water-level declines in
the area, which induced upward migration of
more highly mineralized water into the aquifer.
|
Basalt–Rijam system is the primary source of water
in the northern part of the basin, although several
wells have been drilled into the Amman–Wadi Sir
system. Since the 1980’s, the Basalt–Rijam system
has been used to supply Amman with drinking
water, with additional quantities extracted for
agricultural uses.
In the central part of the Azraq Basin, water in
the Amman-Wadi Sir system is mineralized and
sulfurous and of generally poor quality, with total
dissolved solids concentrations ranging between
800 and 2,500 milligrams per liter (mg/L). In the
western and northwestern rims of the basin, the
quality is good with total dissolved solids concentrations
between 200 and 500 mg/L.
Water Data Banks Project,
Multilateral Working Group on Water Resources,
Middle East Peace Process
Overview of Middle East Water Resources
Information about this document.
