Collecting rain to address Maldives' water shortage
Nasreena Ahmed recalls how, when she was younger, her family and neighbors on Ihavandhoo Island could rely on groundwater for bathing, drinking, and cooking. But years of population growth, ineffective sewage systems, and encroaching salt water have made the groundwater unsafe to use.
Now, Ms. Ahmed, 45, and her family of eight rely on a 2,500-litre tank to collect rainwater for their household. In months with little rain, the tank runs dry and the family has to buy costly bottled water.
The Maldives is the world’s lowest-lying nation. Its highest point is only 2.4 metres above sea level. The country’s small atoll islands are extremely vulnerable to flooding and coastal erosion. Rising seas and extreme weather also threaten the scarce freshwater resources.
With support from UNDP and funding provided by the Adaptation Fund, the Maldives Government started a “pilot integrated water management system” on the densely populated island of Ihavandhoo, with similar projects in the works on Mahibadhoo and Gadhdhoo. The plan will include a reverse osmosis plant for desalination and networks of connected rainwater tanks to safely store and treat water for use during the dry season.
Since land for rainwater catchments is scarce, the project takes a more innovative approach: using buildings as catchment areas. The idea is to create a network of public and private buildings that collect excess rainwater into interconnected water harvesting tanks. The rainwater is then piped to a central water supply plant where it is treated and eventually pumped into people’s homes.
When completed, the integrated water supply systems will increase freshwater storage capacity and provide freshwater for over 6,200 people on the three islands. Moreover, the design allows for future expansion of the network, as more households and buildings are connected. The system is also designed to enhance artificial groundwater recharge, improve the quality and quantity of water in aquifers, reduce contamination from household effluents, and prevent runoff into sensitive reef ecosystems.
A “willingness to pay” survey, and a cost-benefit analysis showed that the system can operate at an affordable cost at or below current market rates. The government of the Maldives manages the project and will train technicians to maintain the water system once the project is complete.
Ms. Ahmed is optimistic about the project, but her desire for results is clear: “I think the project is very good, and finally we are seeing something happen", she said.
Several steps were taken in the design process to include a social impact analysis. Communities were consulted to voice possible concerns and the Ihavandhoo island council was involved in the planning, which helped address potential disputes. The council chose the site for the plant, and played an important role in obtaining permission and arranging compensation for palm owners whose trees would be cut down.
The president of Ihavandhoo’s council, Mohamed Sameer, is positive about the process. “The government came to us with a vision, but they included our ideas. This is a good design for our island,” he says. He also noted that two of the three technicians for the plant have been recruited locally.
The rainwater-storage network and desalination plants are expected to produce between 15-50 litres per day per person by 2030.