Proposed Diversion of Water from Rivière Du Poste and Pradier Canal at Arnaud into Mare aux Vacoas Reservoir

With the increase in demand in the Mare aux Vacoas Water Supply System, the Mare aux Vacoas reservoir suffers supply deficiencies. This situation might further exacerbate due to the effect of climate change with longer dry periods and more intense short duration rainfall. It has also been observed over the past few years that the reservoir starts depleting as from the months of July/August and lasts for about (6 – 7 months) until the onset of the next rainy season (February). The reservoir situation remains below the long term average storage as from the months of August/ September. As such, additional water resources mobilization to the reservoir is required.

Preliminary studies have shown that there is the possibility for harnessing flood and base flows from River du Poste downstream of the Tatamaka Canal intake. As such the Consultancy Services to study same was launched in July 2009 and the Feasibility Study (Phase I) has been completed and has shown potential for harnessing an additional 10 Mm 3 of water yearly at Mare-aux-Vacoas reservoir through the construction of a diversion structure on Rivière du Poste in the vicinity of the reservoir.

The Feasibility Study has been favourably considered by the Project Plan Committee and the detailed design study together with the preparation of the bid document will be allocated to the same Consultant and is expected to be completed in September 2010. The construction of the diversion structure is scheduled to start by end 2010. The diversion structure is expected to be operational by September 2011.

Bagatelle Dam Project

The objective of the Bagatelle Dam Project is to create the necessary water infrastructure to meet the present and future water demand of the Port Louis and Lower Plaines Wilhems regions up to 2050 as well as to increase water availability for irrigation to the extent possible. Presently, these regions experience considerable shortages of water during the dry season.

The Feasibility Study for the Bagatelle Dam Project which was completed in April 2006 recommended a dam to be constructed across River Terre Rouge with a diversion from River Cascade. Both rivers are tributaries of Grand River North West. The Consultancy Contract for the Detailed Design and Construction Supervision has been awarded in January 2009.

Following the recommendations of the Feasibility Study, the Consultancy Contract for the Detailed Design and Construction Supervision of the Bagatelle Dam was awarded in January 2009 for about Rs 170 m. The study is in progress and the basic design has already been completed. The detailed design and the bidding documents ready for inviting bids shall be submitted in May 2010. The construction of the dam is expected to start by October 2010 and be completed by December 2013. The storage capacity of the dam will be 14 Mm 3 with a regulated annual yield of 24 Mm 3. The Bagatelle Dam Project will cost around Rs 3.0 billion (dam, water treatment plant and pipelines).

The EIA study for the Bagatelle Dam Project was awarded in October 2008 and has been completed. No major environmental impacts have been identified. The EIA consultation and licence are under process.

Rehabilitation of La Ferme Dam

Dam safety analysis of La Ferme Dam was carried out in 1999 and it was recommended that the dam be rehabilitated to enhance its structural and hydraulic stability together with its raising to increase the storage capacity.

Rehabilitation works comprise, inter alia, the following components:-

The whole works are expected to be completed by December 2011.

Rivière des Anguilles Dam Project

The present water supply system in the South of Mauritius has reached the limits of its capacity and is, in some periods, not even capable of satisfying the actual demand of potable and irrigation water. Presently, water supplies are met from river abstraction and groundwater as there is no impounding reservoir supplying the project area to ensure security of supply.

To harness additional water resources for the southern parts of the island the Feasibility Study of the South Mauritius Water Supply Project was launched in 2006 and completed in December 2008. It has recommended the construction of a dam on Rivière des Anguilles having a storage capacity of approximately 14 Mm 3 and with a yield of approximately 50 Mm 3/yr.

The Detailed Design of the dam has been completed and draft bid documents have already been prepared.

Consultancy for EIA study has been awarded in March 2010 and shall be completed in August 2010.

Survey works for the land acquisition for the construction of the dam will start in May 2010.

The construction of the dam is scheduled to start in early 2011.

Master Plan for the Development of Water Resources of Mauritius

The contract for the Consultancy Services for the preparation of a Master Plan for the development of the water resources of Mauritius has been awarded in March 2010 for a sum of Rs 45 million. The study will start during this month and be completed within 18 months.

The selected Consultant will, inter-alia:-

At the early stages of this study, the Consultant will give priority to the mobilization of additional water resources for the Northern part of Mauritius for the various time horizons up to 2050. Following the Consultant’s recommendations a full fledge feasibility study and detailed design of the identified projects will be carried out.