Groundwater levels declining rapidly

Groundwater reservoirs in the UAE are suffering rapid and unrecoverable depletion while comprehensive and sound water management strategies and regulations are still to be set, warned a local specialist.

"The country today suffers from a general scarcity of water resources, depletion of groundwater reservoirs and contamination by a wide application of agricultural chemicals and the oil industry.

"This requires urgent and tailored measures to be undertaken by the authorities concerned," said Dr Zeinelabidin Rizk, Director of the Institute of Environment and Water at Ajman University of Science and Technology.

The fast depletion of groundwater resources is a result of excessive pumping for all purposes, and limited recharge.

The amount of recharge for groundwater is estimated at 100 million cubic metres per year, while pumping it for the agricultural sector alone takes out 800 million cubic metres.

This has led to a sharp decline in groundwater levels of all water bearing units in the country, with an average decline of one metre per year, increasing to three metres in Al Ain, Al Dhaid and Liwa areas.

"If the present groundwater pumping rates were to continue in future, most of the non-renewable aquifers will be exhausted and the renewable ones will be greatly threatened by lack of sufficient recharge and escalating salinity, making water unfit for most purposes."

Dr Rizk said another problem is oil pollution which affects both surface water and groundwater resources. It is associated with all stages of oil activities, including exploration, extraction, transportation, refining, storage and use.

Wide application of chemical fertilisers on farmland represents a fatal danger for groundwater resources, because they seep through the soil, reaching the reservoirs.

In addition, most of the usable groundwater contained in water-bearing units is in direct contact with the atmosphere and all surface activities, such as usage of fertilisers. This is causing alarming pollution to drinking water in some areas of the UAE.

"The WHO has defined the limit of nitrate concentration in drinking water as 45 milligrams per litre. In several areas such as Liwa and Al Ain, nitrate concentrations of over 500 milligrams per litre were measured during field studies I have conducted myself," he said.

There should be technical bases for water utilisation and extraction depending on the type, nature and boundary condition of each water-bearing unit in the country, he said.

But precise figures are missing. There are only scattered efforts on calculation of groundwater budgets in some areas, such as in Al Ain, where the United States Geological Survey and the National Drilling Company implemented the Groundwater Research Project. But they are small and isolated trials.

"Data on the overall countrywide picture are still missing. It can be managed properly only if you know the elements of its budget, that is how much water is in store, how much is recharged, how much is withdrawn, etc."

This task is difficult, but recent investigative techniques can be implemented if reasonable budgets are allocated for this purpose.