First National Communication Water Resources

Water Resources

The low rainfall quantities in most of the Kingdom are expected to create limited surface water.  The quantities of the annual runoff are estimated to vary “between” about 5,000 to 8,000 million cubic meters (MCM) of which 780 MCM are produced in the Arabian shelf and the rest are in western coastal parts of the Kingdom.  The storage capacity of 215 constructed dams of different shapes and sizes is 833 MCM (personal communications, 2004).  These dams were constructed for groundwater recharge, surface storage and flood control purposes.  The available surface water for use is about 2230 MCM including the dams’ storage.
Groundwater is stored in more than 20-layered principal and secondary aquifers of different geological ages (Figure 7).  The Arabian Shelf includes the deep sedimentary aquifers which are formed mostly of limestone and sandstone that overlay the basement rock formation known as the Arabian Shield, and covers about two third of Saudi Arabia or 1.485 million km2 .  These aquifers crop out in the western parts of the Shelf and extend towards the eastern parts.  The isotopic analyses showed that the fossil groundwater in the above aquifers is 10,000-32,000 years old. Large volumes of groundwater are stored in the sedimentary aquifers.  The renewable groundwater resources are mainly stored in the shallow alluvial aquifers and within Basalts, which extends mostly in the southwestern parts of Saudi Arabia with varying thickness and width.  These aquifers store about 84 BCM with an average annual recharge of 1,196 MCM.  The total national groundwater reserves in the shallow and deep aquifers to a depth of 300m below ground surface are about 2,259 (BCM).  These assessments need to be updated because they were mostly based on investigations carried out before more than fifteen years. 
 
It is estimated that about 1,400 MCM of wastewater are generated in the country in the year 2000.  The volumes of collected and treated wastewater are about 534 MCM, which represent about 38% of the total generated wastewater, and 33% of the total distributed domestic water.  Presently, about 240 MCM of the treated wastewater are reused annually for landscape and crop irrigation purposes. 
 
The total water production from desalination plants increased from about 200 MCM in 1980 to 540 MCM, 785 MCM and 1050 in 1990, 1997 and 2001 respectively.  The desalinated water production is expected to reach about 1600 MCM in 2010 and more than 2500 MCM in 2025.  The present production represents about 50% of the total domestic and industrial demands, and the rest is from limited surface water and mostly from groundwater resources in shallow and deep aquifers.  By 2025, the desalination production is expected to be about 54% of the total domestic and industrial demands.  The available water resources in the country from conventional and non-conventional resources are summarized in Table 3.


Figure 3.3.1 The extension of the outcrop areas of principle and secondary aquifers in agricultural regions in Saudi Arabia

Table 3.3.1 Available Water resources in Saudi Arabia in 2001-2003(MCM)

Surface water

5,000-8,000 (2,230 available for use)

Groundwater resources

2,269,000 (84,000 renewable groundwater in shallow aquifers)

Groundwater recharge

3,958 (1,196 to shallow aquifers and 2,762 to deep aquifers in the Arabian Shelf)

Desalination

1,050

Treated wastewater

240


3.3.1 Water Supply and Demand Overview

The domestic and industrial water demands have grown from about 220 MCM in 1970 to about 2030 MCM in 2000, and expected to reach 6,450 MCM in 2020.  The industrial demands represent less 10% and 2% of the total domestic and industrial demands, and the national demands respectively (table 4).  The growing domestic and industrial water demands are mainly satisfied from desalination plants and from the non-renewable groundwater resources.  The cultivated areas have expanded from less than 400,000 ha in 1971 to 1.62 million ha in 1992, and started to decrease in 1993 until it reached about 1.21 million ha in 2000.  The total irrigation water use has increased from about 6,108 MCM in 1970 to about 9,470 MCM, about 18,776 MCM and 19,074 MCM in 1980, 1990 and 2000 respectively (Tables 4). 
 
The total volumes of available renewable water resources from surface water and groundwater recharge are about 6,188 MCM.  Non-renewable groundwater resources supplied about 37%, 67% and 66% of the total national needs in 1980, 1990 and 2000 respectively (Table 8).  The domestic and industrial water use depends mainly on desalination processes in satisfying about 50% of the demands while the other 50% is supplied by groundwater from the local aquifers near cities and towns.  It is clear from table 6 that the dependence on nonrenewable groundwater has increased from 37% of the national demands in 1980 to 67% and 71% in 1990 and 1992 respectively, and then decreased to 66% in 2000 due to production of more desalination water and to reduction in agricultural areas after 1993.  The reuse of treated wastewater especially for irrigation has been very low (less than 1%), and is expected to grow significantly in the near future with improvement of water management as will be discussed below. 


 
Table 3.3.2  The growth of water use in Saudi Arabia between 1970 and 2000 (MCM)

YEAR

Domestic and Industrial

Agriculture

Total

Domestic

Industrial

Total

1970

200(3.2%)

20(0.3%)

220

6,018(69.5%)

6,238

1980

446(4.4%)

56(0.6%)

502

9,470(95.5%)

9,972

1990

1508(7.4%)

190(0.9%)

1,698

18,776(91.7%)

20,474

1995

1550(6.7%)

230(1.0%)

1,780

21,498(92.4%)

23,278

2000

1800(8.5%)

290(1.4%)

2,090

19,271(90.2%)

21,361


Table 3.3.3 Water Supply in Saudi Arabia (MCM)

Water source

1980

1990

1992

2000

Treated wastewater effluents

110

(1%)

110

(0.5%)

110

((0.4%)

240

(1.1%)

Desalination

200

(2%)

540

(3%)

540

(2%)

1050

(5%)

Surface water & and recharge to shallow and deep aquifers (renewable water)

6,000

(60%)

6,000

(29%)

6,000

(26%)

6,000

(28%)

Groundwater(nonrenewable)

3,662

(37%)

13,824

(67%)

16,628

(71%)

14,071

(66%)

Total

9,972

20,474

23,278

21,361


3.3.2       Assessment of Impacts of Climate Change on Water Resources

3.3.2.1 Impacts of Climate Change on Groundwater Recharge and Surface Water

Any increase in ETo will result in increasing the evaporation rates and decreasing the available water supplies from annual participation by:

 

·                     lowering the annual recharge to aquifers

·                     Lowering the surface runoff.

The calculated total annual recharge to all aquifers in the Arabian Shelf is about 2,762 MCM based on several hydrogeological studies.  The annual recharge to shallow aquifers in the Arabian Shield is 1,196 MCM.  Thus, the total annual recharge to all aquifers in the Kingdom is about 3,958 MCM.  The average increase in reference evapotranspiration ETo, which reduces the recharge to all aquifers has been defined as 2.3%  and 12% of the total annual recharge at 1 oC and 5 oC increase in temperature respectively.  The calculated reduction in the values of total annual recharge is about 91.4 MCM and 475 MCM at 1 oC and 5 oC increase in temperature respectively. 

3.3.2.2 Impacts of Climate Change on Surface Water

The reduction in annual surface runoff of 5,000 – 8000 MCM at ETo increase of about 2.3%  and 12% at 1 oC and 5 oC increase in temperature respectively have been calculated .  At 1 oC increase in temperature, the increase in ETo of 2.3% will result in decreasing the annual surface runoff by about 115 -184 MCM (with an average of 150 MCM).  While at 5 oC increase in temperature, the increase in ETo of 12% will result in decreasing the annual surface runoff by about 600-960MCM (with average of 780 MCM).   The total annual reduction in water resources equals to reduction in recharge and surface runoff.  Thus, the total water resources reduction will be about 241 MCM and 1,435 MCM at 1 oC and 5 oC increases in temperature respectively. 

3.3.2.3 Impacts of Climate Change on Irrigation Water Demands

The calculated increase in ETo has been used to calculate the increase in irrigation requirements of various crop types in different regions of the Kingdom at 1 oC and 5 oC increases in temperature.  The Total annual irrigation demands increase in the Kingdom ranges from 602 MCM at 1 oC to 3122 MCM at 5 oC increases respectively.

3.3.2.4 Impacts of Climate Change on Domestic and Industrial Demands

The domestic and industrial water use increase at 1 to 5 oC has been assumed to be about 5% and 25% respectively.  Thus, the expected rise in domestic and industrial demands will range between 75 and 390 MCM at 1 oC and 5 oC increases in temperature respectively.

3.3.2.5 Total Water Stresses Prediction

The total water stress is equal to the total quantities of decrease in groundwater recharge and surface runoff, increase in irrigation requirements and domestic and industrial demands at 1 oC and 5 oC increases in temperature.  The calculated total water stress ranges between 1520 to 4,947 MCM at 1 oC and 5 oC increases in temperature respectively (Figure 8).

Figure 3.3.2 Stress on Water Resources as a Result of Climatic Change (MCM)

3.3.3. Socio-economic Impacts
The described impacts of climate changes in above sections on desertification and water resources in Saudi Arabia are expected to have significant effects on socio-economic conditions in the Kingdom.  The welfare, development and survival of urban and rural communities and the sustainability of the national economy are directly affected by the impacts of climate change on water resources and desertification. These impacts can be explained in the followings:

3.3.3.1             Socio-Economic Impacts from Increasing Water Demands

The possible climate change is expected to induce significant increases in water demands for domestic, industrial and agricultural purposes and simultaneously a major reduction in water supply conditions in terms of qualities and quantities. The domestic and industrial water demands of about 2030 MCM in 2000 are expected to increase by 75 and 390 MCM at 1 oC and 5 oC increases in temperature respectively. The costs of the above rises in water demands will represent additional burden on water authorities and the citizens as it should be supplied from desalination processes for domestic use. The expected costs will exceed one billion Saudi Riyals annually as the costs of drinking water production and distribution is about SR 4 (personal communication with the Ministry of Water and Electricity).  This represents about ten percent of the present costs of total national water supplies.  The stress on domestic water supplies will be aggravated by the possible decrease in groundwater recharge and surface runoff with temperature increase.  This means that the domestic water supplies of 50% from groundwater and surface water will be replaced partially or totally from desalination processes. The related costs of these supplies will exceed SR 4 billions annually.  If these increases in domestic and industrial demands are not satisfied then more water supplies problems in rural and urban areas will be experienced. The human, construction, commercial, transportation, education, health and industrial activities will be negatively disrupted.   This will lead to serious effects on social and economic development and sustainability of the national economy and progress of the country. 

3.3.3.2 Socio-Economic Impacts from Increasing Agricultural Water Demands

The government used the agricultural development for accomplishing several objectives.  In addition to contribution to food security, socio-economic developments and national gross domestic product (GDP), it has been important mean for the protection of the structure of local communities and minimization of the impacts of urbanization on rural areas, by the improvement of standard of living through a stable and better source of income, training and settling the nomads into agricultural and prosperous communities, and by the introduction of effective public services such as health and education, and commercial facilities.  The total given loans between 1973 and 1998 were 178,624 loans for a total value of SR 29.5 billion ($7.7 billion). The total given support for wheat and barley production has been about SR 55,459 billions (US$14.87 billions) between 1979 and 2000.  About SR 16.659 billions (US$ 4.44 billions), SR 3.808 billions (US$ 1.015 billions) and SR 7.884 billions (US$ 2.102 billions) have been given for imported barley, poultry feed and agricultural inputs such as fertilizers and machinery respectively during 1974 and 2000.  The total given supports is SR 83.81 billions (US$ 22.34).  The values of given total supports in addition to loans are SR 113.31 billions (US$ 30.216 billion).  New agricultural infrastructure including wells, pumps, sprinkler irrigation and drip systems were introduced in these remote areas, and hundreds of thousands of hectares of desert lands were reclaimed and converted into productive farms.  

The comprehensive agricultural developments especially after 1974 have contributed in achieving self sufficiency in five agricultural commodities.  These are poultry meat and eggs, milk, wheat, dates and most of vegetables types.  In 1999, the agricultural sector accounts for 6.7% of the total Gross Domestic Product (GDP), and equivalent to the GDP of the industrial sector.  The values of agricultural GDP to total GDP in percentage has grown from 1.1% in 1974 to about 6.7 in 1999.  The agricultural GDP has grown from SR 994 millions in 1969 to SR 34,443 millions in 1999 or by 994%, while, the national GDP has grown from SR 16,611 millions to SR 512,354 millions or by 31% during the same period.  The value of agricultural GDP in 2000 at current prices was SR 35,600 millions.  All above values indicate clearly that the agricultural sector became as an essential productive sector which has been contributing significantly to the national economy even after the reduction of supports and incentives to agriculture between 1984 and 2000. 

The total irrigation water use has increased from about 6,108 MCM in 1970 to about 19,074 MCM in 2000. The climate change will result in increasing the annual irrigation water use by about 602 and 3,122 MCM at 1 oC and 5 oC increases in temperature respectively.  It will be difficult under decreasing surface runoff.  The expected rise in irrigation demands will lead to losses in crop yield if not compensated.  These expected yield losses of different types of field crops (including cereals, vegetables and forage crops) and fruit trees (including date palms) will range between 5 and more than 25%.  The value of these losses represent more than the actual profit for farmers from agricultural activities in different regions of the Kingdom. This represents a serious challenge to survival of the agricultural sector as a major economic sector in the national economy. Compensation of the crop losses importation from foreign countries represent additional burden on the economy. Furthermore, the agricultural activities represent a major supporter for about 25% of the national population who still live in rural areas.  The deterioration of agriculture for rural communities represents a threat to the social structure and welfare of these communities.

3.3.4 Adaptative Measures

The government has been instrumental in supporting different programs for minimizing the impacts of possible climate changes on water supplies for satisfying the growing demands for domestic, agricultural and industrial purposes.  The available groundwater resources in deep and shallow aquifers and limited surface water have been utilized to satisfy about 90% of the total national demands.  The rest of demands have been supplied from seawater and brackish desalination processes.  Advanced measures have been implemented to protect the sustainability of water resources and to satisfy the demands in urban and rural areas for different purposes.  These measures include:

Execution of a long-term investigation program to assess the availability of groundwater and surface water resources in different regions.  The government has adopted the development of aquifers and surface water on the bases of these studies. 

The government has supported drilling of thousands of wells under the supervision of the Ministry of Agriculture for domestic, agricultural, and industrial purposes (as explained in Section 3.4.1.B). 

  • The government has supported the construction of 215 dams for water storage and groundwater recharge for domestic and agricultural uses (as explained in Section 3.4.1.A).
  • Building of 30 desalination plants to supply about 50% of the domestic water supplies in the Kingdom (as explained in Section 3.4.2.B).
  • Establishment of the Ministry of water and Electricity in July 2001 to improve the national water planning and management in the country.
  • Development and implementation of water protection and conservation regulations.  These include well drilling permission, drilling supervision and specifications, groundwater protection zones, groundwater pumping schemes, groundwater pollution, surface water development and water conservation.  
  • Construction of wastewater treatment plants and implementation of wastewater reuse schemes for landscape and crop irrigation in different regions of the Kingdom.
  • The introduction and implementation of advanced water conservation support policy at house level.
  • Implementation of modern leakage detection and control schemes in major cities.
  • Implementation of advanced irrigation water conservation schemes for large and small farms.
  • Modification of water pumping from aquifers by changing the agricultural policies to maintain the long-term sustainability of the aquifers.

3.3.5 Conclusions

Most of Saudi Arabia has limited renewable water resources in addition to groundwater in deep and shallow aquifers.  These limited resources are very sensitive to climate change.  Assessment of the impacts on water resources indicated clearly that most regions have high vulnerability levels for climate change impacts on water resources.  The total annual reduction in recharge and surface runoff will be about 241 MCM and 1,435 MCM at 1 oC and 5 oC increases in temperature respectively.  On other hand, the climate change will also increase the domestic and industrial water demands by about 75 and 390 MCM at 1 oC and 5 oC increases in temperature respectively.  This will lead to more water problems to satisfy the increasing domestic, industrial and agricultural demands.  The costs of the above rises in water demands will represent additional burden on water authorities and the citizens as it should be supplied from desalination processes for domestic use. The expected costs will exceed one billion Saudi Riyals annually as the costs of drinking water production and distribution is about SR 4 (personal communication with the Ministry of Water and Electricity).  This represents about ten percent of the present costs of total national water supplies.  The stress on domestic water supplies will be aggravated by the possible decrease in groundwater recharge and surface runoff with temperature increase.  This means that the domestic water supplies of 50% from groundwater and surface water will be replaced partially or totally from desalination processes. The related costs of these supplies will exceed SR 4 billions annually.  If these increases in domestic and industrial demands are not satisfied then more water supplies problems in rural and urban areas will be experienced. The human, construction, commercial, transportation, education, health and industrial activities will be negatively disrupted.  This will lead to serious impacts on social and economic development and sustainability of the national economy and progress of the country.  Deterioration of water supplies, rainfall, surface runoff and aquifer recharge will be having serious impacts on the social survival and structure in rural areas. The welfare of these communities will be seriously threatened.  Consequently, the sustainability of economic development and the social structure in rural areas will be under serious challenges.  National economies would be adversely affected not only by the direct impacts of climate change, but also through the cost of adaptive measures and the knock-on implications of changes elsewhere. Quantitative estimates of financial costs are expected to suffer larger relative economic damages.