Mauritius: Protecting Groundwater Through the Establishment of an Indicator and Monitoring Framework
The government of Mauritius has launched an in-depth study of the Northern Aquifer, a vitally important source of fresh water in Mauritius. The initiative is expected to provide comprehensive information about the groundwater resource and the twin risks of contamination and salt water intrusion. Improved understanding, by both engineers and local communities, will help the people of Mauritius to adopt integrated approaches to water management, with the goal of protecting precious groundwater resources and ensuring sustainable water supply.
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Photo credit: IWRM AIO SIDS
The Northern Aquifer is one of five main underground water reserves on the island of Mauritius. It consists of about 30 domestic pumping stations, 56 industrial boreholes and 62 agricultural boreholes and plays a vitally important role in the social and economic life of Mauritius − particularly the northern plains where agriculture is the main economic activity. By 2025, the northern plains will require about 133 million cubic metres of water per year for the irrigation of agricultural crops; an expanding tourism industry, coupled with a burgeoning population, will also increase demand for water.

The Northern Aquifer currently contributes between 50 and 60 percent of water used for domestic purposes, such as washing and drinking, but it is susceptible to over-exploitation and pollution from agricultural chemicals, sewage and wastewater. Moreover, a brackish saltwater intrusion has been detected up to two kilometres from the coast during the dry season. With a view to improving knowledge of the complex geological structure of the Northern Aquifer (and the quality of its water) a partnership and co-finance arrangement has been established between the the Global Environment Facility, United Nations Development Programme and the government of Mauritius through its Ministry of Energy and Public Utilities/Water Resources Unit (WRU). A demonstration project is being implemented with the objective of adopting and implementing Integrated Water Resources Management (IWRM) approaches and protecting the aquifer. This is part of a broader regional United Nations Environment Programme and UNDP implemented project financed by the Global Environment Facility (GEF) aiming at promoting IWRM in six small island states from the Indian and Atlantic Ocean: Comoros, Maldives, Mauritius, Seychelles, Sao Tome and Principe and Cabo Verde.

The demonstration project is structured around four components, each of which involved the implementation of a number of activities. The first component consisted of an assessment of the freshwater/seawater interface and groundwater quality, and the establishment of a Geographical Information System (GIS). Five boreholes were drilled, each of which was fitted with multi-level piezometers, instruments that allow for the sampling of groundwater at different depths. A water quality monitoring programme was put in place to effect regular sampling and laboratory analysis and make recommendations on the state of the aquifer. In the long run, such testing is expected to establish a water quality baseline that will allow water authorities to continuously assess the vulnerability of groundwater resources against pollution and over abstraction, and provide information necessary for decision making.

The GIS activity will allow for the mapping of the hydrogeological features of the Northern Aquifer and the capture, storage and analysis of information relating to its exploitation. One of the advantages of this exercise is that it will enable the WRU and the Central Water Authority of Mauritius to gauge more accurately the potential of the Northern Aquifer. Components two and three are concerned with the assessment of improvements in wastewater collection and disposal, and water demand management, respectively. The use of injection boreholes for the disposal of treated wastewater will be assessed by investigating impacts on the nearby lagoon. Laboratory equipment have also been purchased.

Component four is focused on education and awareness raising. An national awareness campaign on television, radio and billboards was launched to encourage water users to take ownership and responsibility for water saving, and protection of groundwater resources. The campaign was supplemented by a series of formal, school-based seminars and talks in community centres aimed at encouraging the population of Mauritius to recognise the importance of freshwater resources and the need to use them responsibly. A three dimensional model that represents the geological structure and underground water circulation of the Northern Aquifer is also being designed for the purpose of demonstrating its dynamics to water users.

“Based on the experience of this IWRM demonstration project, the government of Mauritius is currently looking at replicating the project to the 4 other aquifers of Mauritius with the ultimate goal of securing water resources and the future health and well-being of the people”, said Simon Springett, the UN Resident Coordinator in Mauritius.

As such the project addresses the paragraph 64 of the SAMOA Pathway on water and sanitation and directly feeds into the 2030 Agenda for Sustainable Development and its 17 Global Goals. In particular, it will help ensuring availability and sustainable management of water and sanitation for all (Goal 6). It also responds to the need to take urgent action to combat climate change and its impact particularly in Small Island Developing States (Goal 13). Finally the project should build on existing initiatives to develop measurements of progress on sustainable development that complement gross domestic product, and support statistical capacity-building in developing countries (Goal 17).

For more information, contact: Geraldine Deblon, IWRM AIO SIDS Communication Officer at GeraldineD@unops.org

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