Mauritius is currently facing a significant challenge in water management. The country's seven main reservoirs are only 42.1% full on average, a stark decrease from 92.6% around the same time last year, reports the Water Resources Unit of the Ministry of Energy and Public Utilities. Although recent rainfall has brought some relief, it hasn't been enough to alleviate concerns, especially with the La Ferme reservoir at a mere 24.7% capacity.
This sharp decline in water levels, driven by unprecedented high temperatures and prolonged droughts, underscores a growing crisis in the availability of drinking water. As the island grapples with these issues, rainwater harvesting emerges as a vital solution. But what are the first steps?
An underexploited potential
Mauritius receives an impressive annual average rainfall of 4,000 mm, yet only 7% to 9% of this water is effectively captured and utilized, falling short of the country's needs. Compounding the problem is an inadequate storage infrastructure and substantial distribution network leaks, where up to 40% of water is lost before it reaches consumers. As a result, areas like Curepipe, Rose-Hill, and Quatre-Bornes frequently face water cuts.
The benefits of rainwater harvesting
Adopting rainwater harvesting can significantly mitigate the impact of these water shortages. It provides a practical solution to water cuts and alleviates the strain on reservoirs. Rainwater can fulfill up to 50% of a household's non-potable water needs, including gardening, car washing, and running household appliances like toilets and washing machines.
Consider this: a 150 m² roof can collect approximately 3,000 liters of water from just 20 mm of rainfall. By utilizing harvested rainwater for non-drinking purposes, households not only conserve high-quality drinking water but also reduce their water expenditures.
Benefits for businesses and the hospitality sector
Water shortages highly impact the tourist and industrial sectors. By implementing rainwater harvesting systems, many hotels have significantly reduced their consumption of potable water while promoting an eco-friendly approach to their clients. This not only conserves water but also enhances their reputation for sustainability among environmentally conscious tourists.
Daily actions to collect rainwater at home or in your business
Rainwater harvesting is more than just a contingency plan; it's a long-term commitment to sustainability. Both individuals and businesses can adopt simple, cost-effective measures to reduce their reliance on potable water, save money, and help protect the environment. Making these practices part of everyday routines contributes to more sustainable water management, crucial for tackling the ongoing climate challenges.
Four easy-to-implement rainwater collection systems
- Install gutters and tanks: Fit gutters around the roof to channel rainwater into barrels or reclaimed tanks. This stored water can be used for gardening or cleaning purposes.
- Create a collection basin: Dig a small hole in a suitable area and line it with a waterproof tarp to collect rainwater. This method is both easy and inexpensive.
- Use a bucket or basin: Simply place a bucket or basin beneath the downspouts during rainfall to quickly gather water for watering plants.
- Install a homemade "first flush" system: Improve water quality by diverting the initial flow of rainwater, which carries most of the debris and pollutants, away from your storage tank using a simple diversion pipe.
To ensure the collected water is clean enough for non-potable uses, such as cleaning or flushing toilets, it's advisable to filter it through a cloth or sieve before storage.
Long-term solutions
Rainwater harvesting in Mauritius is a collaborative effort involving both individual commitment and support from private and public sector projects.
Collection systems
In Mauritius, the common sheet metal roofs are particularly effective for rainwater collection. When equipped with gutters designed to handle heavy rainfall, these systems can quickly accumulate significant volumes of water, as mentioned above. However, enhancing the infrastructure to improve water capture and storage is crucial to prevent this valuable resource from being wasted, especially by flowing into the sea.
Notable initiatives include the 3 Frères Car Wash in Port-Louis, which, in response to the water crisis, has adopted a waterless washing system to conserve water. Similarly, other businesses in areas like Terre-Rouge are investing in rainwater harvesting systems to decrease their reliance on potable water and reduce operational costs.
Filtration and storage issues
The installation of storage tanks is vital for conserving collected rainwater. Polyethylene tanks offer an easy and affordable solution, while concrete tanks are preferred for their ability to inhibit algae growth, ensuring better water quality.
To further enhance water quality, a "first flush" filtration system is recommended. This system diverts the initial flow of rainwater, which contains the highest concentration of impurities, thereby ensuring that the water collected is cleaner for non-potable uses such as irrigation and cleaning.
Maintenance and prevention
Ensuring the quality of stored rainwater and preventing mosquito breeding are crucial. It is recommended that fine mosquito nets be installed over tank openings and that biological larvicides be used to control mosquito populations effectively without harming other wildlife. Regular maintenance is also essential. Cleaning filters and gutters after the dry season helps remove dust and debris, maintaining the system's efficiency and water cleanliness.
Institutional and financial support
Several supportive initiatives are available for those interested in rainwater harvesting.
For individuals
Rainwater Harvesting Scheme, a program supported by Mauritius Commercial Bank (MCB), helps individuals install rainwater harvesting systems through low-interest loans and grants, making sustainable water solutions more accessible.
FinClub Green Loan promotes environmental sustainability, allowing individuals and businesses to finance projects like rainwater harvesting. It covers up to 100% of installation costs and offers competitive rates starting at 8%, along with a 15% tax credit, making green investments financially attractive.
For organizations and businesses
Government subsidies are available for schools and religious institutions, encouraging the adoption of rainwater harvesting systems on a large scale. This financial support helps alleviate the initial costs and fosters broader implementation.
Business Mauritius supports businesses, especially in the industrial and hospitality sectors, in adopting sustainable water management practices. Through audits, technical advice, and collaborative projects, Business Mauritius assists companies in reducing potable water use and enhancing their environmental reputation. These efforts not only reduce costs but also improve corporate sustainability profiles.
These initiatives underscore the commitment of both the public and private sectors to integrating rainwater harvesting as a fundamental part of sustainable water management in Mauritius.
Current water usage restrictions
Due to critically low water reserves and ongoing drought conditions, the government has enforced stringent restrictions on the use of drinking water. Since February 17, 2025, car washing and the use of high-pressure cleaners have been banned.
To ensure adherence to these measures, enhanced monitoring efforts are in place. Police patrols are actively identifying and penalizing offenders. Fines for non-compliance can be substantial, reaching up to Rs 50,000 for individuals and Rs 200,000 for businesses, with possible prison sentences of up to two years for severe violations. These strict penalties underscore the seriousness of the water scarcity issue and the importance of conserving our water resources.
Future prospects for water management in Mauritius
Recent rainfall has highlighted the significant waste of uncollected rainwater, underscoring the urgent need for improved rainwater management strategies. To maximize the benefits of rainwater harvesting, it is crucial to expand storage infrastructure and promote supportive public policies. Enhancing government subsidies and promoting green loans are effective strategies to encourage widespread adoption of these sustainable practices.
