Rainwater harvesting is not a modern practice. It has been practised since ancient times and it is still used to address current water challenges. Konstantina Toli, Senior Programme Officer with GWP Mediterranean, writes a blog post about lessons from the GWP regions.
“When that I was and a little tiny boy,
With hey, ho, the wind and the rain,
A foolish thing was but a toy,
For the rain it raineth every day.”
Shakespeare, Twelfth Night
Rain: a toy, a nuisance, a source of disaster, a source of life. It quenches the thirst of plants, crops and animals and sustains their life. When strong, it can cause flooding. When it starts, we run away to find shelter. When scarce, we plead for some more. When wise, we harvest it.
Rainwater harvesting is not a modern practice. It has been practiced since ancient times. Elaborate water harvesting, conveyance and storage systems from as early as the Bronze Age can be found in the Minoan civilisation in Greece (from ca. 3500 BC); the Indus Valley Civilization (3000-1500 B.C.); the Mayan in Central America (from 2000 BC) or later the Incas in Peru (from 1200 AD). Sophisticated rainwater harvesting systems providing water to palaces, cities and villages can be found in each civilization. Some of these, like the water collection system in Tikal, Guatemala, built by the Mayas (200-900 AD) is considered a masterpiece of low-cost water engineering, which can offer significant lessons and can be replicated, adapted to modern needs, as people move to the highlands to farm nowadays.
Many areas around the world face water scarcity. Among these, numerous islands, mainly due to their small catchment areas and poor or seasonal rainfall. For them, rainwater has always been a valuable water resource.
Rainwater harvesting is part of the tradition in the Greek islands, where local materials are employed and expertise was developed. Santorini Island, a global landmark of natural beauty yet with very limited fresh water resources, boasts of its water management heritage, with ancient findings from as early as the Cycladic civilisation (ca. 3100-1600 BC). The island has a unique heritage of hand-crafted rainwater harvesting cicterns, constructed by local craftsmen and plastered using Theran soil from the volcano eruption. Hundreds of cisterns are scattered all over the island: in houses, communities and plots of land. Yet, as in most islands, in the past few decades, with the expansion of the water supply networks, rainwater harvesting has been abandoned, while the demand for water increases, resulting to unsustainable solutions to cover it.
Many Greek islands encounter water scarcity challenges due to their limited freshwater resources and impacts of emerging climate vulnerability, thus putting local water security at risk. This affects the local economic activities, which depend on seasonal tourism and small scale agriculture, as well as the ecosystems safety.
GWP Mediterranean, acknowledging the need to revive this traditional practice in the water scarce Greek islands, developed the “Rainwater Harvesting (RWH) Programme in the Greek Islands”, in 2008. Through a multi-stakeholder partnership, it brought together the local authorities of the islands, the private sector (Coca-Cola system and The Coca-Cola Foundation) and a regional organisation. The RWH Programme has a holistic approach and evolves around 4 pillars: rainwater harvesting applications in public building and areas showcasing various technologies available; educational programme for students and teacher trainings; capacity building for local authorities to manage their water resources efficiently and training for technicians on how to enhance local expertise on installing and maintaining RWH systems; and awareness raising on critical water challenges and the potential of rainwater harvesting to cover domestic secondary uses, as well as farming needs.
Due it is acknowledgement by the local communities for its contribution to change the mindset of water use to a more sustainable, mobilising also non-conventional water resources, The RWH Programme has since 2011 expanded to the Maltese islands, then in Cyprus and recently in Sardinia Italy. For its holistic approach and the contribution to local water security and climate change adaptation, GWP-Med received the second global award as a Water Showcase at the 7th World Water Forum (April 2015, Rep, of Korea) and continues its efforts to expand it in other water scarce areas around the Mediterranean.
Similar to the challenges in the Mediterranean, across the globe, Central America has experienced drought for the past 3 years, which has had a significant impact on the population at large, but particularly those who live in the Dry Corridor of Central America and the “Arco Seco” of Panama. GWP Central America has identified strategic allies to implement water harvesting pilot projects in the Dry Corridor of Honduras to provide an alternative to water scarcity in rural communities. Many communities in this area have no other water source and the responsibility of providing water for the homes usually falls on the most vulnerable: women and children.
Pilot projects implemented in the region included the installation and maintenance of rainwater harvesting systems in Honduras, with a geomembrane bag. Going beyond installation, GWP Central America carried out a training for women who live in rural areas and are community leaders. These women were trained on how to install and maintain such a rainwater harvesting system at home. Empowering and training them to fit this low-tech system at home, made them more confident and positive. Having a water resource at home, provided through a water harvesting system, changes their lives. Following the success of the training on RWH, the training will be replicated in El Salvador and beyond.
The project also involved actors from the private sector (AMANCO-Mexichem-a private global company that manufactures plastic pipes), and CARE-PROSADE, a project that promotes food security in southern Honduras and allowed synergies with the academia (Zamorano University in Honduras). A demo system was installed in an agricultural plot, in order to showcase the potential of rainwater harvesting for agricultural use.
While water scarcity is not always the main challenge, in other areas, lack of water supply networks can be the driving force behind rainwater harvesting. In the Caribbean, several communities in various countries, such as Antigua and Barbuda; Barbados; The Bahamas; Dominica; Dominican Republic; Jamaica; Martinique; St. Lucia; St. Kitts and Nevis; St. Vincent and the Grenadines are not connected to a water supply network. For these communities, rainwater is a valuable source of water-sometimes, the only one available. GWP Caribbean saw its potential and started promoting and demonstrating modern rainwater harvesting practices that could be adopted by water scarce communities to secure water availability. They built a model rainwater harvesting system as an educational resource to enhance awareness of rainwater harvesting in the region and created the Rainwater Harvesting Toolbox. Since 2010, the model has toured the region in every possible event, demonstrating a safe way to harvest and reuse water for domestic use. At the same time, they created a resource kit the rainwater harvesting toolkit, where one finds all necessary information on how to build a rainwater harvesting system, health and safety regulations and tips, best practices and technologies available. This open source tool has been a valuable resource for the Caribbean, enabling the uptake of related technologies in the region.
In a changing world, with increasing population and needs for water, rainwater harvesting can provide a reliable source of water fit for secondary uses as well as for farming. GWP regions have taken various steps towards mobilising this resource, in their efforts to contribute to local water security and climate change adaptation. A number of technologies, from low-cost to high-end are available and able to cover all needs for rainwater harvesting, under various climatic and other conditions. Know-how and experience is accumulated and shared through the GWP network and beyond. All what is left, is our action to harvest water, It’s easy! Just try it out!
Learn more: GWP Mediterranean, GWP Central America, GWP Caribbean