WATER
RESOURCES *
The Sultanate
of Oman lies in an arid region of the world, but due to its size and
the configuration of its topography there are considerable variations
of climatic conditions within the country. Only in the extreme south
where the seaward facing slopes of the mountains and the coastal plain
have the benefit of light summer monsoons extending from June to September
is rainfall regular. In the north of Oman heavy and very localised thunderstorms
occur over the Hajar range of moun tains during the summer months, and
in the winter occasional depres sions sweeping across the Arabian Peninsula
bring rain to the Interior and coastal regions. Nevertheless, rainfall
is sparse and sporadic, and lengthy periods of drought are frequent
On rare occasions majority clonic storms sweep into Oman from the Indian
Ocean to produce large volumes of rainfall in Southern and Central regions.
Exploring
Water
The art
of exploiting available water resources to the best advan tage has been
perfected by Omanis over the centuries. An example of this is the falaj
(plur. aflaj) system, which was introduced into Oman about a thousand
years ago, and used throughout the Interior as a means of irrigation.
Water is tapped at the water table in the mountains and in wadis, and
is led by man-made subterranean channels or by channels that skirt and
cling to mountain sides to areas of settle ment where at the surface
it is used for irrigation and domestic pur poses. Elsewhere, and especially
in the coastal regions, water for irri gation is obtained from wells.
Raising
Water Demand and MWR
In recent
years the balance achieved over the centuries has been upset by the
introduction of modern methods of extracting subterranean sources of
water and the subsequent increase in the areas under culti vation. Diesel
and electrical pumps have replaced animal power as a means of raising
water from wells. Other pressures on available water resources arise
from increasing agricultural productivity, the increas ing demands of
a developing industrial sector, which was previously non-existent, and
the mounting demands for domestic water as popu lation and living standards
rise. Desalinated sea water now meets an increasing proportion of the
domestic requirement in some coastal re gions.
Since the
start of the renaissance in 1970 the Government, under the leadership
of His Majesty Sultan Qaboos bin Said, has been keenly aware of the
need to conserve available water resources and to use them to the best
advantage. In 1975, the Water Resources Council was formed. This was
followed by the formation of a Public Authority for Water Resources,
charged with identifying and assessing the natural water resources.
In 1986, two Councils concerned with the environment and water resources
were merged into the Council for the Con senation of the Environment
and Water Resources, of which His Majesty the Sultan was the Chairman.
In 1988 the country's water resources were declared "natural wealth"
by Royal Decree. In 1989 it was decided that water was of such paramount
importance that the Ministry of Water Resources (MWR) was established
by Royal Decree. In January 1994, a Royal Decree was issued making the
development and maintenance and the jurisdiction and records of dams
and aflaj the responsibility of the Ministry of Water Resources.
The principal
aim of the MWR is to conserve and develop the natural water resources
of the Sultanate, and to initiate long-term policies for these resources
to support the economic and social development of the country. Initial
emphasis was given to the development of the in frastructure of the
Ministry, regulation of water use, the expansion of the water monitoring
network, and water resources assessment projects. More recently the
Ministry has broadened its scope by giving priority to the assessment
of projects that support expanding municipal demands, that can identify
all possible new resources, that evaluate development schemes to ease
water shortages in some areas, and also to the initiation of other water
management projects.
The Ministry
has met the major challenge of water use regulation by a national campaign
of well registration. By July 1990,167,000 wells had been registered
by citizens. In the past few years 24,000 ap plications have been received
by regional Water Resource departments for the sinking of new or replacement
wells, the deepening of existing wells and the repair of wells and aflaj.
Violations of regulations and appeals against Ministry decisions are
also handled by Water Resource departments. Since 1991,1,800 violations
have been investigated, but the numbers have been declining through
greater Ministry vigilance and cooperation of the general public.
Well
Inventory
A national
well inventory currently being conducted is confirming well registrations
and collecting information required to support current permit policy
and future policies for water usage. The inventory was commenced in
1992 following evaluation of one-year pilot projects in three regions.
Work initially concentrated in the Batinah coast of northern Oman where
50% of wells were registered in 1990 and where the adverse effects of
the sa line intrusion are most severe. Inventory on the Salalah Plain
and Al Wusta areas were completed last year. 
By last
year 50,000 wells had been inventoried, in the course of which water
samples have been col lected and analysed providing baseline data for
environmental monitoring, which will be consolidated in a national water
quality database. Work has now extended into the Interior, and the major
part of the project should be completed by the end of this year. To
carry out its aim of planning a long-term strategy to develop the water
resources of the Sultanate, the Ministry needs to establish how much
natural water is available, 97% of which exists as groundwater. Virtually
all monitoring of rainfall, wadi flows, groundwater levels and chemistry
have been carried out within the last twenty years, so Oman has few
measurements or records extending back into the past from which it can
infer trends on water availability, except for areas such as Muscat,
Salalah and Nizwa. As a result, the Ministry has expanded its groundwater,
surface water and meteorological monitoring networks. All the data from
these networks is stored in the Ministry's growing technical database
to form a national water resources data bank.
Water
Avaiability
Among the
Ministry's major tasks has been the need to refine knowledge of available
water resources, evaluate stocks, and search for new sources. A most
significant find so far has been an aquifer in north western Oman, the
Al Massarat aquifer as revealed by His Majesty Sultan Qaboos during
his armual tour of the Wilayats in January 1994. Phased development
of this aquifer will bring relief to areas around Ibri, Dank/Yanqul
and Bahla which have seen the quali ty and quantity of their natural
water deteriorate over the past few years. Rapid assessments have been
carried out over the whole country, which have enabled the Ministry
to estimate water balances for the nine major catchment regions. More
detailed studies are focusing on areas which are known to be experiencing
particular problems of water supply and which are also undergoing more
rapid growth.
The southern
Batinah, where groundwaters have been affected by sea wa ter intrusion,
is the subject of a groundwater modelling study. This will help to show
the rate at which the aquifers are being affected by water of higher
salinity, and their response to changes in rainfall, re charge and pumping
from boreholes. A detailed drilling programme is currently proceeding
in the Sumail Gap which marks the route be tween the capital area and
Nizwa along which there are several grow ing centres of population.
Drilling programmes at Adam were com pleted almost two years ago. Detailed
geological and hydrogeological studies have been carried out in Wadi
Dayqah near Muscat, which is one of the few perennially flowing wadis
in the country. The assessment report on these studies was submitted
in 1994. Further southeast, extensive research is being carried out
in Wadi Al Batha, which lies between the northern moun tains and the
northern edge of the Wahiba Sands. Assessment pro grammes aim to quantify
just how much water can be relied on to sup port future developments.
A study was undertaken in the Nejd of northern Dhofar in 1993 to estimate
the quantities of groundwater available, and to explore differ ent methods
for its development.
Recharge
Dams
Most of
the water is brackish and fossil water, meaning that there is no, or
very little, recharge to the aquifer in the present day, as it derives
from a past age when the climate was much wetter, so any development
has to be carefully controlled. The Ministry has made significant progress
in planning and development of schemes to increase recharge, provide
surface water storage and to improve aflaj water use efficiency. Recharge
dams are designed to intercept flood flows in wadis, which would otherwise
run to waste in the sea or inland into the desert. Water is released
at a reduced rate of flow often through culverts in the dam and infiltrates
the ground water aquifer beyond the dams in controlled flow. This recharged
water moves gradually in the aquifer to replenish boreholes downstream
of the dams. 
Sixteen
dams have so far been completed and several small dams and water structures
have been built in Jebel Akhdar. Monitoring networks of rain gauges,
wadi flow gauges and boreholes are installed at strategic sites behind
and downstream of the dams. When there have been significant periods
of wadi flow, water levels in boreholes downstream of the dams rise
significantly. Over periods of many months, observations of water levels
from over the whole net work show that this recharged water diffuses
to other zones in the aquifers.
The Ministry
of Agriculture and Fisheries prepared a master plan for building recharge
dams in 1986. The original intention was to build 58 dams in preliminary
identified sites, mostly on the coastal and Interior sides of the northern
mountains. During each 5-year develop ment planning period progress
towards this aim is assessed and modi fications are made in the light
of experience. Broadly speaking, the master plan is still being followed
and discussions are now under way for the next 5-year planning period
starting at the end of 1996. The feasibility of building water conservation
structures and their potential for operating successfully is evaluated
fully before building begins. Issues that must be taken into account
in deciding between re charge and retention structures include estimations
of aquifer capacity (how much groundwater the aquifer underlying the
site of the struc ture can hold) and recharge potential (how much of
the intercepted flood flows will actually infiltrate the aquifer, rather
than just be evaporated). Where there is no suitable aquifer, usually
in mountain ous areas with small valleys, a retention structure is more
viable.
Water
Salinity
The assessment
of sea-water intrusion on the Batinah Coast has been examined through
several studies. The most important of these so far was the production
of a series of maps comparing the extent of saline water intrusion and
falls in groundwater levels during the peri od 1983 to 1991. This showed
that significant levels of saline intrusion are taking place along the
entire coastal strip, but particularly in the south from Suwaiq to Seeb.
Here, average
long-term decline in the groundwater level is in the order of 0.5 metres
per year. Similar maps have been produced for the Salalah coastal plain,
where saline intru sion is also increasing. Similar investigations formed
part of the studies of the feasibility of recharge dams in wadis Sumail
and Rusayl. National well inventory data together with preliminary assessments
of the southern Batinah, completed early last year, have also helped
to define the landward ex tent of saline and brackish waters, and the
amount of groundwater abstractions in excess of recharge. These studies
confirm that sea water intrusion is generally increasing along the Batinah.
Management options which have been proposed to alleviate the situation
include the removal of large fodder farms from the Batinah, the introduction
of metering to measure water use, continued well inven tory work, improved
monitoring and several engineering initiatives that will control use
and the intrusion it causes.
MWR
Structure
The Ministry
operates through four Directorate-Generals, which are respectively responsible
for water resources assessment, water resources management, regional
affairs and administration and finance. Staffing levels have increased
more than eight-fold since the creation of the Ministry, which reflects
its increasing activity. 93% of the 1,200 staff are Omani. The Ministry
provides training, ranging from locally based administrative and language
courses to technical MSc courses overseas. Since 1992, 114 staff have
studied abroad, while an average of 500 a year have attended local courses.
The Ministry's headquarters are at present in Ruwi, and there are 11
water resource departments in the regions. The number of regional departments
has doubled in five years. To celebrate the 25th anniversary of His
Majesty's accession and the fifth anniversary of its founding, the Ministry,
helped by the Interna tional Water Resources Association, held an international
conference on Water Resources Management in Arid Countries in Muscat
during March 1995. Two hundred and forty delegates representing 39 coun
tries attended 15 sessions of scientific presentations. 86 papers and
19 posters were presented on 11 topics:
Regional
water management · water resources development · agricultural
water consenation · desalination and brackish water utilisation
· wastewater re-use · saline intrusion · hydrology
· hydrogeology · groundwater recharge · hydrologic
modelling · hydraulic structures.
In his
opening statement, Professor G.O.P. Obasi, Secretary General of the
World Meteorological Organisation, praised the Sultanate's achievements
in the area of water resources, adding that arid regions could learn
much from Oman. Eminent speakers from the World Meteorological Organisation,
UNESCO, the United Nations Environmental Programme and the Arab Organisation
for Agricultural Development gave keynote papers. The closing statement
of the Conference recommended: conserving water use in agriculture through
modern management methods inventorising all water sources and usages
in detail undertaking more research on non-conventional water sources
undertaking further assessment and monitoring of groundwater recharge
and flow undertaking more research on the links between climate and
water resources protecting water sources from pollution integrating
water resources plans and strategies within national policy emphasising
demand management for water emphasising water supply management through
water re-use, water harvesting and water transfer increasing public
awareness of water resources issues. The Ministry was recognised as
being well advanced in many of these areas. The Ministry mounted a technical
exhibition describing the work it is doing, which was very well received
by participants of the conference.
©
Adapted from Oman'95, Ministry of Information. Nizwa.NET is not responsible
for accuracy or errors.
