Water Harvesting Techniques Water Harvesting Techniques i th A b R ii th A b R iin the Arab Regionin the Arab Region

ByByAbdelaziz ZakiAbdelaziz ZakiAbdelaziz ZakiAbdelaziz Zaki

UNESCO Cairo OfficeUNESCO Cairo Office

Water Resources in the Arab regionWater Resources in the Arab regionThe Arab world is facing one of the severest water scarcities in the world.According to WWDR most of the Arab Countries fall underAccording to WWDR, most of the Arab Countries fall under the lower end of the water availability list as well as the quality list.Factors contributing to water resources vulnerability in the Arab Region.– aridity, y,– low rainfall, – high evaporation,

di t ib ti f t– uneven distribution of water resources, – complexity of the hydro-political conditions, – the rapidly growing human populationthe rapidly growing human population, – the deterioration of water quality; and – the accelerated demand for water

Rainfall DistributionRainfall DistributionThere is a severe spatial rainfall distribution over There is a severe spatial rainfall distribution over the Arab region. the Arab region.

Rainfall DistributionRainfall DistributionThe total average annual volume of rainfall is The total average annual volume of rainfall is about about 22,,238 238 billion mbillion m33..Only Only 22..66 66 million Kmmillion Km22 receives receives 11,,488 488 billion mbillion m33

constituting constituting 1919%% of the total area of the Arab of the total area of the Arab regionregionregion, region, while while 406 406 billion mbillion m33 of rain fall on of rain fall on 1515%% of the total of the total areaareaarea. area. Two thirdsTwo thirds of the Arab region is arid and hyper arid of the Arab region is arid and hyper arid deserts (deserts (99..24 24 million Kmmillion Km22) and receives ) and receives 344 344 billion billion mm33 of rainfall.of rainfall.

Renewable Water ResourcesRenewable Water ResourcesThe estimated renewable water resources in the The estimated renewable water resources in the Arab region range from Arab region range from 246 246 to to 441441Billion mBillion m33 with with g gg gan average of an average of 340 340 Billion mBillion m33 (Salih (Salih 20022002). ). The total average annual volume of rainfall is The total average annual volume of rainfall is

b tb t 22 238238 billibilli 33 t ib ti lt ib ti l 180180 billibilliabout about 22,,238 238 billion mbillion m33 contributing only contributing only 180 180 billion billion mm33 of renewable surface and groundwater of renewable surface and groundwater resources. resources. esou cesesou cesAdditionally, the region receives Additionally, the region receives 160 160 billion mbillion m33 of of surface water from catchments outside the Arab surface water from catchments outside the Arab region.region.The average annual recharge to groundwater is The average annual recharge to groundwater is estimated atestimated at 4545 Billion mBillion m33 whereaswhereas 135135 Billion mBillion m33estimated at estimated at 45 45 Billion mBillion m33, whereas , whereas 135 135 Billion mBillion m33

is available in wadi system.is available in wadi system.

Water Harvesting SystemsWater Harvesting SystemsWater Harvesting SystemsWater Harvesting Systems

There are different water harvestingThere are different water harvestingThere are different water harvesting There are different water harvesting techniques practiced in the Arab region. techniques practiced in the Arab region. They can be grouped into two categories:They can be grouped into two categories:They can be grouped into two categories:They can be grouped into two categories:

i.i. Water harvesting and storage systems; andWater harvesting and storage systems; andiiii W t h ti d di tW t h ti d di tii.ii. Water harvesting and spreading systems;Water harvesting and spreading systems;

Survey of traditional water harvesting Survey of traditional water harvesting systems has revealed that some systems has revealed that some 11 11 systems are used in the Arab region. systems are used in the Arab region.

Distribution of traditional water system in the Arab States, after UNESCO Cairo (1995)

Category Name of system

rdan

-Ara

b m

irat

eshr

ein

nisi

geri

a

udi A

rabi

a

dan

ria

aq

man

tar

uwai

t

bano

n

bya

ypt

rocc

o

uret

ania

men

Jor

Un-

Em

Bah

Tun

Alg

Sau

Sud

Syr

Ira

Om

Qat

Ku

Leb

Lib

Egy

Mor

Mau

Yem

Cisterns x x x x x x x x x Small dams x x x x x x x x x x x x x x Hafirs x x x x x x x x x x Tree trunks x te

r ve

stin

g st

orag

e em

s

Wat

harv

and

syst

e

Koroum / Ghadirs x x x x x x x

Terraces / Masateh x x x x x x x x x x

Irrigation di i d x x x x x x x x x xg

and

ms

diversion dams Water spreading dykes x x x x x x x x x x

Miskat x x Artificial recharge x x x x x x x at

er h

arve

stin

gre

adin

g sy

stem

recharge

Wa

spr

Check dams x x

Water Harvesting in the Arab Region:Water Harvesting in the Arab Region:Overview and ExamplesOverview and ExamplesTerracingTerracinggg

Terracing is successfully used for rainfall utilization and soil Terracing is successfully used for rainfall utilization and soil conservation in the mountainous areas of south western Saudi Arabia conservation in the mountainous areas of south western Saudi Arabia and Oman. and Oman. Terracing is widely used in Yemen as one of the effective conservation Terracing is widely used in Yemen as one of the effective conservation techniques techniques Different forms of terracing are available depending on its purposeDifferent forms of terracing are available depending on its purposeDifferent forms of terracing are available depending on its purpose Different forms of terracing are available depending on its purpose such as soil conservation and water use. such as soil conservation and water use. Rained agriculture is practiced on terraces in many communities, more Rained agriculture is practiced on terraces in many communities, more 11 55 million hectares have been regularly cultivatedmillion hectares have been regularly cultivated11..5 5 million hectares have been regularly cultivated.million hectares have been regularly cultivated.

Spate Irrigation Spate Irrigation (flood irrigation)(flood irrigation)It mainly counts on water spreading where the flood water is divertedIt mainly counts on water spreading where the flood water is divertedIt mainly counts on water spreading where the flood water is diverted It mainly counts on water spreading where the flood water is diverted from the wadi course to an immediately adjacent cultivated area. from the wadi course to an immediately adjacent cultivated area. Agricultural land is graded and divided into basin for storing enough Agricultural land is graded and divided into basin for storing enough water to allow enough water to be stored for the season Thereforewater to allow enough water to be stored for the season Thereforewater to allow enough water to be stored for the season. Therefore, water to allow enough water to be stored for the season. Therefore, soils should be with sufficient water holding capacity.soils should be with sufficient water holding capacity.In large wadis with high discharges, a temporary earth dams created in In large wadis with high discharges, a temporary earth dams created in order to retard the flow and receive the first wave of floodorder to retard the flow and receive the first wave of floodorder to retard the flow and receive the first wave of floodorder to retard the flow and receive the first wave of floodSpate irrigation is practiced in Sudan, Yemen, Oman, Tunisia, Algeria Spate irrigation is practiced in Sudan, Yemen, Oman, Tunisia, Algeria and Saudi Arabia.and Saudi Arabia.

Country Year of Irrigation data

Spate irrigation area (h )

Total irrigation area (h )

% of spate irrigation

Spate Irrigated areas versus total irrigated areas in some Arab countries (FAO, 1999)

(ha) (ha) coverageYemen 1987/1997 98,320 481,520 40 Algeria 1992 110,000 555,500 20 Morocco 1989 165,000 1,258,200 13, , ,Tunisia 1991 30,000 385,000 8 Sudan 1995 46,200 1,946,200 2.5

Meskat Meskat The Miskat System is one of the ancient methods employed inThe Miskat System is one of the ancient methods employed inThe Miskat System is one of the ancient methods employed in The Miskat System is one of the ancient methods employed in harvesting rainwater. harvesting rainwater. They are used in the Arab Maghreb specially in Tunisia, Morocco and They are used in the Arab Maghreb specially in Tunisia, Morocco and the north west of Libya in Nafousa mountainthe north west of Libya in Nafousa mountainthe north west of Libya in Nafousa mountain. the north west of Libya in Nafousa mountain.

Dams and ReservoirsDams and ReservoirsDams of various sizes were constructed in most Arab countries for the Dams of various sizes were constructed in most Arab countries for the purposes of irrigation, flood control and groundwater recharge. purposes of irrigation, flood control and groundwater recharge. Dams assist in reducing flood damage downstream by reduce theDams assist in reducing flood damage downstream by reduce theDams assist in reducing flood damage downstream by reduce the Dams assist in reducing flood damage downstream by reduce the magnitude of peak discharge. magnitude of peak discharge. Sediment which carried by floods is trapped upstream dams creating Sediment which carried by floods is trapped upstream dams creating good soil for agriculturegood soil for agriculturegood soil for agriculture. good soil for agriculture. Most of the dams built in Saudi Arabia, the United Arab Emirates and Most of the dams built in Saudi Arabia, the United Arab Emirates and Oman were for the purpose of recharge to depleted aquifer systems.Oman were for the purpose of recharge to depleted aquifer systems.Few large dams in Saudi Arabia Egypt Tunisia Sudan and JordanFew large dams in Saudi Arabia Egypt Tunisia Sudan and JordanFew large dams in Saudi Arabia, Egypt, Tunisia, Sudan and Jordan Few large dams in Saudi Arabia, Egypt, Tunisia, Sudan and Jordan have multihave multi--purposes. purposes. These dams have been built either at the head waters of catchments in These dams have been built either at the head waters of catchments in the mountainous regions or in the downstream portions of catchmentsthe mountainous regions or in the downstream portions of catchmentsthe mountainous regions or in the downstream portions of catchments the mountainous regions or in the downstream portions of catchments as in Saudi Arabia, Sudan, Egypt, Tunisia, Jordan, Yemen, the United as in Saudi Arabia, Sudan, Egypt, Tunisia, Jordan, Yemen, the United Arab Emirates, and Oman. Arab Emirates, and Oman.

Water harvesting projects in two major wadis in Egypt: Case StudiesEgypt: Case Studies

MultiMulti--purpose water harvesting projects in W. Ghuweiba and purpose water harvesting projects in W. Ghuweiba and W. Wateir in Egypt. Studies were carried out by the Water W. Wateir in Egypt. Studies were carried out by the Water R R h I i f ER R h I i f EResources Research Institute of Egypt. Resources Research Institute of Egypt.

W. Ghuweiba W Watier

Cairo

W. Watier

31 O t 02 11 57 AM31 Oct 02 11:57 AM

Wadi Wadi Ghuweiba Ghuweiba ProjectProjectWadi Ghuweiba area is about Wadi Ghuweiba area is about 2500 2500 kmkm22 and its main stream and its main stream length is length is 130 130 km. km. The Wadi has strong slopes range between The Wadi has strong slopes range between 10 10 and and 28 28 m/km m/km and elevations betweenand elevations between 13001300 m to aboutm to about 100100 m.m.and elevations between and elevations between 1300 1300 m to about m to about 100 100 m. m. Industrial zone is constructed in its delta. Industrial zone is constructed in its delta. Field geoelectrical survey was conducted in Wadi Ghuweiba Field geoelectrical survey was conducted in Wadi Ghuweiba

i ii i 1616 ti l El t i l S di (VES)ti l El t i l S di (VES)comprising comprising 16 16 vertical Electrical Sounding (VES). vertical Electrical Sounding (VES).

An artificial recharge system was suggested to increase the An artificial recharge system was suggested to increase the rate of recharge to the Quaternary aquiferrate of recharge to the Quaternary aquiferrate of recharge to the Quaternary aquifer. rate of recharge to the Quaternary aquifer. Six locations were employed to induce infiltration into the Six locations were employed to induce infiltration into the Quaternary aquifer. Quaternary aquifer. Dams’ heights ranged between Dams’ heights ranged between 3 3 and and 7 7 meters with meters with capacities ranged between capacities ranged between 60 60 to to 6500 6500 thousands mthousands m33..

Stored water lasts for Stored water lasts for AA22--3 3 weeks according weeks according

its volumeits volumeEvaporation rateEvaporation rateEvaporation rate Evaporation rate ranges from ranges from 88--12 12 mm/daymm/day

Recharged water to different aquifers (1000 m3)Return periods (years) Subbasin’s

Name Average

5-yr 10-yr 25-yr 50-yr 100-yr

Shona 1260 840 3360 5460 10440 13320

Recharged water to different aquifers (1000 m3)

Shona 1260 840 3360 5460 10440 13320

Khafory 2501 2066 3515 7760 11360 13930

Esaimer 88 88 184 264 516 814

Abiad 43 36 70 180 228 598Abiad 43 36 70 180 228 598

AA 638 510 829 3168 3550 13345

Noot 46 23 57 132 234 435

Wadi Watier ProjectWadi Watier Project

Wadi Watier (about Wadi Watier (about 3600 3600 kmkm22) in southeastern Sinai, Egypt ) in southeastern Sinai, Egypt The catchment area is covered by basement rocks, mainly The catchment area is covered by basement rocks, mainly y , yy , ygranites which are highly fractured.granites which are highly fractured.The international road between Egypt and Jordan and The international road between Egypt and Jordan and several tourist villages are seasonally subjected to the flashseveral tourist villages are seasonally subjected to the flashseveral tourist villages are seasonally subjected to the flash several tourist villages are seasonally subjected to the flash floods of Wadi Watier.floods of Wadi Watier.

Basin Boundary

Town

Wadi Watier ProjectWadi Watier Project

For the purpose of water For the purpose of water resources development of resources development of th d t i i ith d t i i ithe area and to minimize the area and to minimize the harmful destruction the harmful destruction effects of Wadi Wateir effects of Wadi Wateir flash foods seventeenflash foods seventeenflash foods, seventeen flash foods, seventeen detention dams and five detention dams and five storage dams were storage dams were proposed.proposed.p pp p

For economic reasons, the For economic reasons, the probable floods ofprobable floods of 2525--probable floods of probable floods of 2525years were selected to years were selected to design the different kinds design the different kinds of control works.of control works.

Dams locations were selected upon field investigations Dams locations were selected upon field investigations according to the most practical and suitable sites taking intoaccording to the most practical and suitable sites taking intoaccording to the most practical and suitable sites taking into according to the most practical and suitable sites taking into consideration the construction process and transportation of consideration the construction process and transportation of the equipments and materials. the equipments and materials. Two types of dams were proposed, the detention and theTwo types of dams were proposed, the detention and theTwo types of dams were proposed, the detention and the Two types of dams were proposed, the detention and the storage dams, according to the amount of runoff volume storage dams, according to the amount of runoff volume from each subbasin.from each subbasin.

Dam’s Type Reservoir C it

Reuse of recharging water for Reuse of recharging water for groundwater aquifers, asgroundwater aquifers, as

Detention StorageCapacity

(1000m3)

D1 147 D2 199

S1 900groundwater aquifers, as groundwater aquifers, as indirect contribution, can indirect contribution, can cover the requirements of cover the requirements of about about 3000 3000 feddans/year.feddans/year.

S1 900D3 147

S2 7,810 D4 230 D5 87

Another positive impact is the Another positive impact is the creation of a good creation of a good

S3 1,125D6 145 D7 200 D8 204 D9 180gg

agricultureagriculture--land upstream the land upstream the proposed structures amount proposed structures amount to about to about 500 500 feddans. feddans.

D10 312 D11 200

S4 3,400 D12 367 D13 55D14 130 D15 213

S5 3.800 D16 173 D17 4.5D17 4.5

Water Harvesting Constraints in the Arab Water Harvesting Constraints in the Arab RegionRegionRegion Region

Rainfall and runoff data availability (short records)Rainfall and runoff data availability (short records)UnUn gauged Catchment conditionsgauged Catchment conditionsUnUn--gauged Catchment conditions gauged Catchment conditions Financial support for establishing monitoring Financial support for establishing monitoring systemssystemssystemssystemsUpUp--scaling problems from experimental scaling problems from experimental catchments (if exist) to water harvesting scalecatchments (if exist) to water harvesting scaleSuitable hydrological techniques for arid Suitable hydrological techniques for arid conditionsconditionsS iS i E i tE i tSocioSocio--Economic aspectsEconomic aspectsHigh cost of water harvesting constructions in the High cost of water harvesting constructions in the Arab region in relation to its immediate useArab region in relation to its immediate useArab region in relation to its immediate use. Arab region in relation to its immediate use. MaintenanceMaintenance

UNESCO Cairo Office activities in UNESCO Cairo Office activities in the Field of Water Harvestingthe Field of Water Harvestingthe Field of Water Harvestingthe Field of Water Harvesting

Enhance capacity building through the organization of WH Enhance capacity building through the organization of WH training workshops (ex.: Sudan, training workshops (ex.: Sudan, 2004 2004 and Jordan and Jordan 20052005))g p ( ,g p ( , ))Foster networking and experience exchange through the Foster networking and experience exchange through the Arab Wadi Hydrology Network (AWHN) coordinated by Arab Wadi Hydrology Network (AWHN) coordinated by ACSADACSADOrganization of the International Conference on Wadi Organization of the International Conference on Wadi Hydrology (every Hydrology (every 2 2 years) years) –– Egypt, Egypt, 20002000, Jordan , Jordan 2003 2003 and Yemen in and Yemen in 20052005..gyp ,gyp , ,,–– The next conference will be in Oman during The next conference will be in Oman during 20072007..

Preparation of technical publication within the AWHN.Preparation of technical publication within the AWHN.Rainfall water Management in the Arab Region (state ofRainfall water Management in the Arab Region (state of–– Rainfall water Management in the Arab Region (state of Rainfall water Management in the Arab Region (state of the Art) edited by A. Salih, Khouri, J, and Amer A.the Art) edited by A. Salih, Khouri, J, and Amer A.

–– Water Harvesting training Manual edited by O. Remawi Water Harvesting training Manual edited by O. Remawi and A Kharabshaand A Kharabshaand A. Kharabsha. and A. Kharabsha.

–– Recent publication is underRecent publication is under--preparation. First draft is preparation. First draft is available.available.

Concluding RemarksConcluding Remarks11 Strengthening the existing hydrological monitoring systemsStrengthening the existing hydrological monitoring systems1.1. Strengthening the existing hydrological monitoring systems Strengthening the existing hydrological monitoring systems

in the Arab regionin the Arab region

2.2. Establishing more new experimental basins in the Arab Establishing more new experimental basins in the Arab g pg pregion for more understanding of the hydrological region for more understanding of the hydrological characteristic of the region.characteristic of the region.

3.3. Establishing regional database and strengthening the Establishing regional database and strengthening the existing ones in the Arab region.existing ones in the Arab region.

44 Encouraging more joint research activities in arid zoneEncouraging more joint research activities in arid zone4.4. Encouraging more joint research activities in arid zone Encouraging more joint research activities in arid zone hydrology.hydrology.

55 Enhancing capacity building and fostering networking inEnhancing capacity building and fostering networking in5.5. Enhancing capacity building and fostering networking in Enhancing capacity building and fostering networking in the field of water harvesting in the Arab region.the field of water harvesting in the Arab region.

6.6. Raising public awareness for increasing the water use Raising public awareness for increasing the water use efficiency with special focus on the ethical dimension.efficiency with special focus on the ethical dimension.

Concluding RemarksConcluding Remarks77 Encouraging the involvement of the stakeholders NGOsEncouraging the involvement of the stakeholders NGOs7.7. Encouraging the involvement of the stakeholders, NGOs Encouraging the involvement of the stakeholders, NGOs

and communities in the maintenance of the water and communities in the maintenance of the water harvesting construction.harvesting construction.

8.8. Enhancing the coordination among the scientific Enhancing the coordination among the scientific institutes in the Arab region for more experience institutes in the Arab region for more experience exchange in the field of water harvesting techniquesexchange in the field of water harvesting techniquesexchange in the field of water harvesting techniques.exchange in the field of water harvesting techniques.