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11 WATER POLITICAL CONCEPT IN TUNISIA: OPTIONS FOR WATER SECTOR DEVELOPMENT

Irrigated agriculture covers 385.000 ha, represents 15% of the GNP and

1.1Water supply/demand and perspectives

1. Water supply

The total water resources potential is estimated at 4,670 billion m3 per year. The table 1. shows the repartition of quantities of different resources by region:

The following table 2 recapitulates the mobilized and can be mobilized resources.

Table 2.

Resources	Resources in billion of m3			Rate of Mobilization
	Potential	Can be mobilized	Mobilized
Surface water Deep underground water Underground water Total	2,7 1,25 0,72 4,67	2,1 1,25 0,72 4,07	1,48 1,0 0,75 3,23	70,5 81 104 79,4

(Source: Ministry of Agriculture)

With a rate of mobilization passing 80%, the strategy of dynamic mobilization of water resources reaches today its limits in fact of the very high economic value of new mobilization projects and the bad quality of underground water no yet mobilized. The almost-totality of the conventional resource will be mobilized thus toward 2010. To this horizon, according to the Ministry of agriculture prevision, the total demand would be 3165 m³, letting a theoretical available of 1500 m³ in normal year.

This theoretical balance, favorable until 2030 mask real unbalances and difficulties increasing:

• 
  The important variability of the rain full (1 to 5 in the north and 1 to 10 in the center and the south) fact that Tunisia is confronted to frequent droughts, especially during these last decades. These situations require restrictions on water demands for irrigated areas.
  
• 
  In much underground water, their overexploitation caused deterioration on quality (excessive saltiness). This problem concerns 27% of surface aquifers implying a monitoring of underground water. 10% of irrigated areas are submitted to the phenomena of Stalinization and require a continuous control.
  
• 
  The quality of waters constitutes a major preoccupation of managers. The quality of thesis resources, 72% of tea surface water potential has salinity low then 1,5 g/l. For the underground water, 8% of these resources have a salinity low then 1,5 g/l, 70% bring in 1,5 and 5 g/l and 21% have more then 5 g/l. For the deep underground water, 20% have a salinity lower then 1,5 g/l, 57% have a salinity between 1,5 and 3 g/l. 23% have a salinity more then 3 g/l.
  
• 
  The silting of dam reduces their useful capacities (global reduction of 20 Mm3/an).
  

In the same way the water demand growth continuously in all sectors and in all regions.

• 
  Drinking water is assured for 100% of the urban population (6 Millions of inhabitants) and 77% of networks (3,5 Millions of inhabitants). Since 10 years, the growth of consumptions (without agriculture sector) is regular with a rate of 3,3% per year.
  
• 
  Since 1980, a hydro-agricultural policy has been developed and caused the double demand for the intensive irrigation.
  

2. Waters demand perspective

Water demand is in substantial increase in all sectors and regions. Currently, the rate of satisfaction in drinking water reaches 100% of the urban population and 80% of the rural population. Tea domestic, industrial and tourist demands increase has continuous way, even though for tea drinking water, tea unites demands are located to tea reasonably low levels with look to tea international norms (110 liters/jour/capita in urban city, 20 to 40 l/j/capita in rural zone). With 385.000 ha irrigated areas and 55.000 ha with complementary irrigation, the agricultural demand doubled during the last 15 years and reached 83% of the total demand valued to about 2.565 Mm3.

The preliminary study « Eau 21 » achieved by the Ministry of Agriculture showed that the available resources permit to satisfy needs in water of the country, provided that to control the demand.

Table3. gives the evolution of water demand of the different sectors until the horizon 2030.