ABSTRACT
The scarce precipitation that falls in arid and semi-arid regions is often torrential. Run-off could be used for aquifer recharge, without the need for heavy economic investment. A case study is presented here of the Campo de Dalías (SE Spain), an area where intensive agricultural activities over the last forty years have required large quantities of gravel and clay for use as the basic substrate on which crops are grown. Accordingly, numerous gravel pits have been opened in recent years and several million cubic metres extracted. Several million cubic metres of clay have also been extracted from the distal sectors of the alluvial fans that descend from the Sierra de Gador and from a large endoreic basin. In the latter pits, wetlands have developed, due very possibly to the rise in the water table in the aquifer beneath. The gravel pits are situated at the apices of the alluvial fans. They overlie hydrogeological units that are widely overexploited and could thus be used for artificial recharge. There are also 107 checkdams in the streams flowing towards the Campo. In addition to increasing the availability of water in the aquifer, the dams also reduce the risks of catastrophic flooding and erosion.
