The Central Water Authority (CWA) operates under the aegis of the Ministry of Renewable Energy & Public Utilities. It is a body corporate, established under the provisions of the CWA Act No. 20 of 1971.

The CWA is responsible for the mobilisation, treatment, quality control and distribution of potable water on mainland Mauritius. The CWA has set as mission:-

“To secure and provide an excellent sustainable water supply service, of appropriate quality, at a reasonable price, which meets the growing needs of the people and to support the Economic Development of the Country”.

Since its formal establishment in July 1973, the CWA has sustainably been undertaking capital development programmes for the development and expansion of the potable water supply infrastructures. The total assets of the Authority is presently evaluated at around 8 Billion Rupees.

Piped potable water is universal in Mainland Mauritius. 98.6% of households have access to piped potable water within their premises.

The CWA ensures service delivery through some 3,985 km of distribution pipeline drawing from 106 service reservoirs, totalling storage capacity of 237,970 m 3/d.

Throughput in the distribution network, currently, averages 545,000 m 3/day. 51% of resources are derived from ground water sources, airlifted through 112 boreholes pumping stations. The balance is from surface sources, mobilised from the following impounding reservoirs:-

Mare Aux Vacoas, Piton du Milieu, La Nicoliere, supplemental water from Midlands Dam through La Nicoliere, Port Louis Municipal Dyke Dam and Riviere du Poste.

The CWA operates 2 slow sand filtration plants and five rapid gravity filtration plants, totalling installed capacity of 315,800 m 3 for the treatment and purification of water from surface services. Because of its excellent quality, water from ground water sources is only chlorinated prior to being injected in the distribution network.

Potable water supplied by the Authority has to conform to the standards prescribed by both the World Health Organisation (WHO) and to the norms specified in the Environmental Protection Act promulgated by the Local Ministry of Environment.

The Ministry of Health and Quality of Life conducts in dependant water quality audits to ensure compliance to the standards set for drinkable water.

Qualitative analyses of raw water resources and for treated water are daily performed by the CWA Scientific Services department. Two testing procedures are conducted, namely direct field analysis and laboratory chemical and biological analysis. Sample tests are conducted for some 32 parameters.

For administrative convenience and service delivery purposes, the CWA has divided the island into six autonomous operational water supply systems/districts.

The profile of each of these water supply systems are summarised herewith:-

1) Port Louis Water Supply System

Service area : 36 km 2

No. of service reservoirs : 16

No. of treatment plants : 1 – Pailles Cap: 55,000 m 3 (SSFP)

Average daily throughput : 94,300 m 3/d

Ground water (%) : 40%

Surface water (%) : 60%

2) District Water Supply System (North)

Service area : 220 km 2

No. of service reservoirs : 19

No. of treatment plants : 1 - La Nicoliere Cap: 66,000 m 3 (RGFP)

Average daily throughput : 94,300 m 3/d

Ground water (%) : 40%

Surface water (%) : 60%

3) District Water Supply System (East)

Service area : 190 km 2

No. of service reservoirs : 13

No. of treatment plants : 1 - Piton du Milieu Cap: 37,000 m 3 (RGFP)

Average daily throughput : 69,925 m 3/d

Ground water (%) : 55%

Surface water (%) : 45%

4) District Water Supply System (South)

Service area : 225 km 2

No. of service reservoirs : 22

No. of treatment plants : 2 – Mont Blanc and Riviere du Poste

(Cap: 25,000) (RGFP)

Average daily throughput : 74,200 m 3/d

Ground water (%) : 57%

Surface water (%) : 43%

5) MAV (Upper) Water Supply System

Service area : 195 km 2

No. of service reservoirs : 18

No. of treatment plants : 2 - 1 Slow Sand Cap: 60,000 m 3

1 Rapid Gravity 70,000 m 3

Average daily throughput : 90,000 m 3/d

Ground water (%) : 17%

Surface water (%) : 83%

6) MAV (Lower) Water Supply System

Service area : 219 km 2

No. of service reservoirs : 18

No. of treatment plants : Nil

Average daily throughput : 95,500 m 3/d

Ground water (%) : 80%

Surface water (%) : 20% (transfer from La Marie T.P)

N.B : RGFP = Rapid Gravity Filter Plant SSFP = Slow Sand Filtration Plant

The CWA derives its income, mainly from water sales. Universal metering is in place. Consumers are charged on the basis of volume consumed. There are nine customer clans. These are:-

The charging policy is based on a two part tariff for each category of its customers. The first part is comprised of a fixed component (basic charge) tied to a certain volume. The 2 nd part of the tariff relates to all consumptions that exceed the allocation tied to the basic charge. The rates are progressive and guided by the different consumption bands. Tariffs were last reviewed in August 2002.

Potable water demand has been sustainably increasing by an average of 3% yearly over the past twenty five years. The trend is likely to continue up to year 2025.

To meet present demand and forcast demand up to year 2025, the CWA would have to implement infrastructure development and expansion programmes estimated at Rs. 3.1 Billion.

The main investments would be for:-