Rising groundwater: a problem of development in some urban areas of the Middle East

Abstract

Rising groundwater has caused considerable, widespread and costly damage to structures and services in many urban areas of the Middle East, and represents a significant hazard to public health. The principal cause is artificial groundwater recharge from potable supplies, sewer systems and irrigation returns which may greatly exceed both the natural rate of recharge and the capacity of the natural subsurface and surface drainage systems to receive them.

Much damage has occurred because the potential for rising groundwater and associated problems were not recognised prior to development, the effect of a higher water table not often being considered in the design of deep basement buildings and buried services. Site-specific remediation is generally costly as considerable damage has often been done prior to implementation. It may also adversely affect adjacent structures or services. Regional groundwater control may be more cost-effective, but problems of settlement due to removal of soluble salts, suspended sediments or rock matrix are often difficult to predict and may have severe consequences.

With hindsight it is possible, from the Middle East experience, to identify mitigation measures which could reduce the impact of rising groundwater upon future developments under similar circumstances. These include (1) water-use control and conservation measures to reduce the rate of artificial recharge, which could be seen as part of an overall water management plan, and (2) the adoption of appropriate planning and construction regulations to enable structures and services to be appropriately designed. It is envisaged that the latter strategy would involve the hydrogeological and geotechnical investigation of the proposed development areas, together with the formulation of a groundwater budget to enable susceptible areas to be identified. Appropriate development, which may include limiting basement depths or giving priority to foul or stormwater sewer systems in susceptible areas, may greatly reduce damage as a result of rising groundwater.