Every Drop Counts: Harnessing Rainwater for Public Facilities in the Arab Region is a brief / practical guidance note published by ESCWA as part of the Climate-Resilient Water Solutions in Jordan and Lebanon project, led by UN-Habitat in collaboration with ESCWA and UNICEF, and funded by the Adaptation Fund. It focuses on rainwater harvesting in public facilities, especially schools, hospitals, community centres, universities, places of worship, and municipal buildings.
Key insights:
The brief explains that water scarcity in the Arab region is not only an environmental issue, but also an economic and social burden. When public facilities face rising water bills, fewer resources remain available for education, healthcare, maintenance, sanitation, and community services.
Public facilities are especially vulnerable because they often depend on municipal water systems or costly tanker deliveries. As water becomes scarcer, the cost of running schools, hospitals, clinics, community centres, and municipal buildings increases.
The brief highlights the severity of water scarcity in the Arab region. More than 50% of Arab countries rely heavily on groundwater as their main freshwater resource, while 90% of the region’s population lives in countries experiencing water scarcity.
In 2020, around 50.8 million people in the region lacked access to basic drinking water services.
The brief notes that 19 out of 22 Arab countries fall below the water scarcity threshold of 1,000 cubic metres per person per year, while 13 out of 22 Arab countries face absolute water scarcity, with less than 500 cubic metres per person per year.
Freshwater withdrawal across Arab countries is forecast to increase by 42% by 2030 compared with 2020 levels, adding further pressure to already limited water resources.
Rainwater harvesting is presented as a practical and sustainable solution for public facilities. By collecting rainwater from rooftops or paved areas and storing it in tanks or underground reservoirs, facilities can meet part of their water needs at relatively low cost.
The collected rainwater can be used for non-drinking purposes such as toilet flushing, cleaning, gardening, laundry, and cooling systems, depending on the level of treatment and local safety requirements.
Rainwater harvesting can reduce water bills, improve service quality, maintain hygiene during shortages, and allow facilities to redirect budgets toward their core work, such as education, health, and community support.
The brief explains that rainwater harvesting systems usually involve collecting, storing, treating, and using water. Some systems treat rainwater before storage, while others store it first and treat it later.
Key design considerations include the intended use of the water, actual water demand, size and type of catchment area, rainfall patterns, storage capacity, and distribution needs.
The implementation process includes assessing the site, designing the system, installing storage and conveyance infrastructure, adding treatment measures, setting up distribution, and maintaining and monitoring the system.
The brief identifies several implementation challenges, including variable rainfall, climate uncertainty, water quality risks, maintenance needs, high upfront costs, competition with piped water, space constraints, property limitations, and governance or ownership issues.
Water quality is a key concern. Collected rainwater can be contaminated by roof materials, dust, or bird droppings, while poorly maintained tanks may encourage microbial growth or mosquito breeding. Regular cleaning, covered tanks, first-flush systems, filtration, and chlorination are therefore important.
The brief recommends practical design adapted to local conditions, clear responsibility for operation and maintenance, institutional support from ministries, dedicated financing, community awareness, integration with national water strategies, and scaling through documented pilot projects.
A major case study is rainwater harvesting in Lebanese public schools. The project introduced rainwater harvesting systems in schools to respond to intermittent water supply, rising water stress, climate change, groundwater overuse, and pollution.
To date, 10 systems are operational across 11 schools, with one system shared between two schools.
Each school received a standardized modular rainwater harvesting system, including rooftop collection pipes, large ground-level reservoirs, filtration units, and chlorination systems for disinfection.
The project also included capacity-building. Local technical and maintenance staff were trained, and more than 3,500 students across 11 schools participated in educational sessions on climate change, water scarcity, water conservation, and how rainwater harvesting systems work.
Schools reported estimated annual savings of around USD 3,000, mainly from reduced spending on trucked water.
The initial implementation cost was about USD 30,000 per system, with an estimated return on investment period of around 10 years.
The brief also highlights the role of these systems during crises. During the 2024 war on Lebanon, many public schools were used as temporary shelters for displaced families, and improved water access helped strengthen sanitation and hygiene conditions.
Main message: Rainwater harvesting can help public facilities in the Arab region reduce water costs, maintain essential services, improve hygiene, and build resilience to water scarcity, climate change, and emergencies. When combined with modular design, regular maintenance, institutional support, and water education, it can become a scalable strategy for strengthening water security in schools, hospitals, community centres, and municipal facilities.
