Seychelles

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GEOGRAPHY, POPULATION AND WATER RESOURCES

The Seychelles archipelago, located in the Indian Ocean about 1 500 km from the east coast of Africa, comprises more than 115 islands, with a total area of 455 km. The archipelago is made up of two groups of islands: the Mah-Praslin group of granitic islands, with a total area of 241 km, and including the two main islands (Maine: 159 km; and Praslin: 42 km); and the other islands, covering 214 km in total and consisting of coral atolls and sand banks. The cultivable area is estimated at 1 400 ha, which is 3 % of the total area, and the cultivated area is about 400 ha, which is 29% of the cultivable area and 0.9% of the total area.

The total population is estimated to be 73 000 inhabitants (1994), of which 41% is rural. Average density is 160/km, but varies from 1/km on the coralline islands to more than 120/km on La Digue and Praslin, and 380/km on Mah. Annual population growth is estimated to be 0.6%, taking into account the emigration of about 1 000 citizens a year.

TABLE 1
Basic statistics and population

Area of the country 1994 45 500 ha
Cultivable land 1989 1 400 ha
Cultivated land 1989 400 ha
Total population 1994 73 000 inhab.
Population density 1994 160 inhab./km
Rural population 1990 41 %
Water supply coverage    
Urban population   - %
Rural population 1985 95 %

The agricultural sector, including forestry and fisheries, represents about 7% of GDP and employs 17% of population. Agriculture alone is only 4% of GDP.

Climate and water resources

The climate is wet tropical (equatorial), with little variation of temperature (27C) and relative humidity (80%) during the year. The climate is dominated by the pattern of monsoons. The southeast monsoon from May to October brings cool winds but little rainfall. The northwest monsoon from November to April brings variable gentle winds, low clouds and heavy rainfall.

Average annual precipitation is 1 742 mm, varying from 2 370 mm on Mah to 1 990 mm/year on Praslin, 1 620 mm/year on La Digue and 1 290 mm/year on average on the other islands. The heaviest rains occur on Mah where the central plateau, with an altitude of 900 m, receives up to 3 500 mm/year, and once even 6 176 mm was registered, while the south of the island receives less than 1 800 mm/year.

Seychelles

TABLE 2
Water balance

Water resources:      
Average precipitation   1 742 mm/yr
    0.8 km/yr
Internal renewable water resources - total   - km/yr
Internal renewable water resources - per caput   - m/yr
Global renewable water resources   - km/yr
Dependency ratio   - %
Total dam capacity   - km
De-salinated water   - 10 6 m/yr
Water withdrawal:      
- Agricultural   - 10 6 m/yr
- Domestic   - 10 6 m/yr
- Industrial   - 10 6 m/yr
Total   - 10 6 m/yr
per caput   - m/yr
as a % of internal renewable water resources   - %
Other withdrawal   - 10 6 m/yr
Wastewater:      
Produced   - 10 6 m/yr
Treated   - 10 6 m/yr
Re-used treated wastewater   - 10 6 m/yr

TABLE 3
Irrigation and drainage

Irrigation potential   - ha
Irrigation:      
1. Full or partial control Irrigation: equipped area   - ha
- surface irrigation   - ha
- sprinkler irrigation   - ha
- micro-irrigation   - ha
% of area irrigated from groundwater   - %
% of area irrigated from surface water   - %
% of equipped area actually irrigated   - %
2. Spate irrigation area   - ha
3. Equipped wetland and inland valley bottoms   - ha
4. Other cultivated wetland and inland valley bottoms   - ha
5. Flood recession cropping area   - ha
Total water managed area (1 + 2 + 3 + 4 + 5)   - ha
- as a percentage of cultivated area   - %
- increase over last 10 years   - %
- power irrigated area as % of water managed area   - %
Full or partial control schemes: Criteria    
Large schemes > - ha - ha
Medium schemes   - ha
Small schemes < - ha - ha
Total number of households in irrigation      
Irrigated crops:      
Total irrigated grain production   - t
as a % of total grain production   - %
Harvested crops under irrigation   - ha
- orchids   - ha
- vegetables   - ha
-   - ha
Drainage - Environment:      
Drained area   - ha
as a % of cultivated area   - %
Flood-protected area   - ha
Area salinized by irrigation   - ha

The granitic islands have many small, steep watercourses, but most of them have only ephemeral flows. No information on surface and groundwater resources is available.

IRRIGATION DEVELOPMENT

Irrigation has been developed in recent years, mainly for complementary water supply to the crops in case of water shortages or droughts. On La Digue, groundwater is used for irrigation.

Orchid farming under irrigation has been developed in recent years, mainly under the supervision of Indian Ocean Nurseries, which is a State farm.

INSTITUTIONAL ENVIRONMENT

The Water and Sewerage Division of the Public Utilities Corporation is responsible for all matters related to water resources throughout the Seychelles.

Agriculture, including irrigated agriculture was under the supervision of the Ministry of National Development through the Agricultural Division. The Division has now become a part of the Ministry of Agriculture and Marine Resources.

TRENDS IN WATER RESOURCES MANAGEMENT

In the Seychelles archipelago, the major water-related concern is that of drinking water. The aquifers in the main islands are unconfined and the water table is close to the surface: only 1 m deep, which is 1 to 2 m above sea level. Therefore the groundwater is subject to contamination by sea water or pollution by human activities, and it is particularly vulnerable when it is overexploited or during droughts. To protect the groundwater, the pumped yield should not exceed a safe limit. Currently, on a long-term basis (one year) this safe limit is not exceeded, but it happens on a short-term basis (one or a few days).

The major objective of the government is to improve and develop the cropped area, in order to reduce imports of foods which could be produced locally. Irrigation and drainage development are one of the means adopted to achieve this goal, but they suppose high-value-added crops, such as orchids. Another means which could be adopted - currently in an experimental stage - is the development of hydroponics.

MAIN SOURCE OF INFORMATION

FAO. 1989. Seychelles, la strategic du secteur agricole. FAO/CI. Rapport 88189 TA-SEY 4. Rome.


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