Potentials and limits of urban rainwater harvesting in the Middle East

Abstract. In the Middle East, water is scarce and population growth causes a rapid rise of urban centers. Since many towns of the Palestinian Authority (PA) suffer from water shortage, the use of rainwater harvesting (RWH) as an alternative to conventional water supply has gained increasing interest among water resources planners. This study quantifies actual volumes of urban RWH to be expected from highly variable Mediterranean rainfall. A one-parameter model uses measured potential evaporation and high resolution rainfall data as input to calculate RWH volumes from rooftops inside Ramallah, a traditional Arab town. While during average seasons a 87% runoff harvest (480 from 550 mm of rainfall) can be expected, this value decreases to about 75% (190 from 250 mm of rainfall) during drought seasons. A survey comprising more than 500 questionnaires suggests that approximately 40% of the houses are equipped with RWH systems from which one third are out of use. Although water quality is perceived to be favourable, only 3% of the active RWH systems are actually used for drinking and only 18% for domestic purposes. All active RWH systems investigated may harvest approximately 16 × 103 m3 of rooftop runoff during an average season and 6 × 103 m3 during droughts. When these numbers are extrapolated to all houses in Ramallah, theoretical maximum potentials increase to approximately 298 × 103 m3 during average seasons and 118 × 103 m3 during droughts. A part of this potential can easily be exhausted by rehabilitation of installed RWH systems. The use of RWH for emergency water supply should be advocated, although care is needed because of hygienic risks. Regional estimates for the entire Lower Jordan River Basin yielded RWH potentials of 20 × 106 m3 during the average season 2002/2003 but only 3 × 106 m3 during the drought season 1998/1999. Thus, urban RWH is a relatively small contribution to overcome water scarcity in the region and decreases significantly during droughts. Yet it is a sustainable water resource, which is available on spot for everybody. Due to population growth and ongoing urbanization it will be more important in future.

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Potentials and limits of urban rainwater harvesting in the Middle East

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-8-10369-2011 ◽

2011 ◽

Vol 8 (6) ◽

pp. 10369-10396 ◽

Cited By ~ 1

Author(s):

J. Lange ◽

S. Husary ◽

A. Gunkel ◽

D. Bastian ◽

T. Grodek

Keyword(s):

Water Quality ◽

Middle East ◽

Population Growth ◽

Rainwater Harvesting ◽

Water Shortage ◽

Small Contribution ◽

Palestinian Authority ◽

Urban Centers ◽

Jordan River Basin ◽

Regional Estimates

Abstract. In the Middle East, water is scarce and population growth causes a rapid rise of urban centers. Since many towns of the Palestinian Authority (PA) suffer from water shortage, the use of rainwater harvesting (RWH) as an alternative to conventional water supply has gained increasing interest among water resources planners. This study quantifies actual volumes of urban RWH to be expected from highly variable Mediterranean rainfall. A one-parameter model uses measured potential evaporation and high resolution rainfall data as input to calculate RWH volumes from rooftops inside Ramallah, a traditional Arab town. While during average seasons a 87% runoff harvest (480 from 550 mm of rainfall) can be expected, this value decreases to about 75% (190 from 250 mm of rainfall) during drought seasons. A survey comprising more than 500 questionnaires suggests that approximately 40% of the houses are equipped with RWH systems from which one third are out of use. Although water quality is perceived to be favourable, only 3% of the active RWH systems are actually used for drinking and only 18% for domestic purposes. All active RWH systems investigated may harvest approximately 16 × 103 m3 of rooftop runoff during an average season and 6 × 103 m3 during droughts. When these numbers are extrapolated to all houses in Ramallah, theoretical maximum potentials increase to approximately 298 × 103 m3 during average seasons and 118 × 103 m3 during droughts. A part of this potential can easily be exhausted by rehabilitation of installed RWH systems. Also, the use of collected water for drinking should be advocated. This should go along with regular checks of water quality and regulations concerning adequate water storage and treatment/disinfection procedures where necessary. Regional estimates for the entire Lower Jordan River Basin yielded RWH potentials of 20 × 106 m3 during the average season 2002/2003 but only 3 × 106 m3 during the drought season 1998/1999. Thus, urban RWH is a relatively small contribution to overcome water scarcity in the region and decreases significantly during droughts. Yet it is a sustainable water resource, which is available on spot for everybody. Due to population growth and ongoing urbanization it will be more important in future.

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Evaluation of dual-mode rainwater harvesting system to mitigate typhoon-induced water shortage in Taiwan

Water Science & Technology ◽

10.2166/wst.2010.280 ◽

2010 ◽

Vol 62 (1) ◽

pp. 140-147 ◽

Cited By ~ 4

Author(s):

M. M. Islam ◽

F. N.-F. Chou ◽

C.-H. Liaw

Keyword(s):

Water Supply ◽

Rainwater Harvesting ◽

Water Shortage ◽

Supply System ◽

Water Supply System ◽

Treatment Level ◽

Government Subsidy ◽

Raw Water ◽

Dual Mode ◽

Design Algorithm

The water shortage of today's world is one of the most challenging problems and the world is looking for the best solution to reduce it. Some human made causes and also natural causes are liable for the shortage of the existing water supply system. In Taiwan, especially during typhoon, the turbidity of raw water increases beyond the treatment level and the plant cannot supply required amount of water. To make the system effective, a couple of days are needed and the shortage occurs. The purpose of this study is to solve this emergency shortage problem. A dual-mode Rainwater Harvesting System (RWHS) was designed for this study as a supplement to the existing water supply system to support some selected non-potable components such as toilet and urinal flushing of an elementary school. An optimal design algorithm was developed using YAS (yield after spillage) and YBS (yield before spillage) release rules. The study result proved that an optimum volume of tank can solve the emergency water shortage properly. The system was found to be more reliable in Taipei area than that of Tainan area. The study also discovered that a government subsidy would be needed to promote the system in Taiwan.

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Assessment of rainwater harvesting for domestic water supply in palestinian rural areas

MATEC Web of Conferences ◽

10.1051/matecconf/201824506012 ◽

2018 ◽

Vol 245 ◽

pp. 06012 ◽

Cited By ~ 4

Author(s):

Nidal Mahmoud ◽

William Hogland ◽

Michael Sokolov ◽

Vasily Rud ◽

Nikita Myazin

Keyword(s):

Water Quality ◽

Water Supply ◽

Rural Areas ◽

Rainwater Harvesting ◽

Quality Measurement ◽

Water Shortage ◽

Economic Feasibility ◽

Domestic Water ◽

Ancient Times ◽

Domestic Water Supply

Rainwater harvesting in Palestine is a principal water resource that had been adopted since ancient times. However, the system had not been subjected to a thorough assessment. This paper aims at assessing the feasibility of rainwater harvesting for domestic water supply in Palestinian rural areas with special emphasis on socio-cultural and financial aspects as well as harvested water quality. Different methods were used to collect necessary data from a case study village, including literature review, observations, questionnaires and water quality measurement of freshly fallen and harvested rainwater samples. Moreover, domestic water demand and water supply from such a system were compared, and economic feasibility of applying this system was checked. The results revealed that harvested rainwater is a viable resource that can contribute considerably to minimizing water shortage.

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ENVIRONMENTAL STUDY ON COLLECTING OF RAINWATER HARVESTING AND DETENTION POND DESIGNING TO REDUCE THE LOADS ONTO SANITARY NETWORKS

Journal of Engineering and Sustainable Development ◽

10.31272/jeasd.25.1.3 ◽

2021 ◽

Vol 25 (01) ◽

pp. 31-43

Author(s):

Muhsin S. Thajeel ◽

◽

Ahmed H. Ali ◽

Khayyun M. Rahi ◽

◽

...

Keyword(s):

Water Supply ◽

Water Resource ◽

Distribution Systems ◽

Water Distribution ◽

Rainwater Harvesting ◽

Water Shortage ◽

Transportation Systems ◽

Environmental Study ◽

Water Transportation ◽

Detention Pond

Rainwaters harvesting has been the vital source of water resource for drinkable and non-drinkable purposes in the ancient eras. As the water transportation systems stayed not used for water supply for these times. At present, the water distribution systems have upgraded, but the request to fresh water is increasing due to the inhabitants growing, and development. The water shortages and presented water supply for drinking are limited, which insisted the specialists working in the water division to search for solutions could be applied to the water deficiency that many countries in the world are facing. Optimization of water habit and the management of water resource will be able to aid to passing water shortage. This work contain the first designing and accumulation of rainwater from the rooftop in Baghdad City. Moreover, designing a detention pond using hydrology studio software programme to store the collected water.

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Establishment of sustainable water supply system in small islands through rainwater harvesting (RWH): case study of Guja-do

Water Science & Technology ◽

10.2166/wst.2010.299 ◽

2010 ◽

Vol 62 (1) ◽

pp. 148-153 ◽

Cited By ~ 7

Author(s):

Mooyoung Han ◽

Jaehong Ki

Keyword(s):

Water Supply ◽

Rainwater Harvesting ◽

Empty Space ◽

Water Source ◽

Water Shortage ◽

System Capacity ◽

Small Islands ◽

Design Modification ◽

Sustainable Water Supply ◽

Unfavorable Condition

Many islands in Korea have problems related to water source security and supply. In particular, the water supply condition is worse in small islands which are remote from the mainland. A couple of alternatives are developed and suggested to supply water to islands including water hauling, groundwater extraction, and desalination. However, these alternatives require much energy, cost, and concern in installation and operation. Rainwater harvesting is a sustainable option that supplies water with low energy and cost. However, lack of practical or comprehensive studies on rainwater harvesting systems in these regions hinders the promotion of the system. Therefore, this research examines defects of current RWH systems on an existing island, Guja-do, and provides technical suggestions in quantitative and qualitative aspects. A simple system design modification and expansion of system capacity using empty space such as a wharf structure can satisfy both the qualitative and the quantitative water demand of the island. Since rainwater harvesting is estimated to be a feasible water supply option under the Korean climate, which is an unfavorable condition for rainwater harvesting, implies a high potential applicability of rainwater harvesting technology to other regions over the world suffering from water shortage.

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