The Bouteldja coastal aquifer is in the extreme Algerian Northeast, in El Tarf region; it covers an area of 160 Km². It consists of recent alluvial deposits (Mio-Plio-Quaternary sands and clay). The annual rainfall average is about 600 mm. The aquifer thickness varies from 40 meters in the southeast part to 200 meters in the Northwest part.
Groundwater recharge in Bouteldja coastal aquifer is due to effective infiltration estimated around 34% of the precipitation, and to lateral groundwater inflows from the adjacent sandstone aquifer in the eastern part. Except for groundwater abstractions, discharge of the aquifer to the sea and the El Kebir valley alluvial aquifer constitutes the main outflows.
|City||Population in 2005||Population supplied (%)||Water distributed(2005)|
|Bouteldja||18548||100%||15.8 million m3|
|Annaba||138040||100%||16.7 million m3|
Bouteldja coastal aquifer represents the main source of freshwater supply of El Tarf and Annaba regions. Since 1996, groundwater availability has significantly decreased. The annual water supply from this aquifer exceeds 35 Mqm/year, which roughly equals the average aquifer natural recharge.
|Aquifer extension||160 km²|
|Total exploitation||35 million m³|
|Major challenges||Salinization of groundwater (seawater intrusion) and agricultural pollution due to the intensive use of fertilization in agriculture and seawater intrusion|
|Cities supplied||Bouteldja coastal aquifer represents the main source of freshwater supply of El Tarf and Annaba regions.|
TDS values vary between 0.6 and 16 g/L in the coastal zones, and between 0.06 and 0.4 g/L in the inland, thus indicating the effects of the two groundwater salinization sources, which are the Mediterranean Sea in the north and the Mekrada wetland in the western part. The expected population growth and rainfall decrease due to climate change indicate the need for more effective water resource management in order to avoid water availability and quality problems.