The Saudi government estimates that the Kingdom has about 630 billion gallons per year, available of renewable water. Saudi Arabia is also the largest producer of desalinated water in the world at 280 billion gallons of water desalinated each year. The main source of groundwater comes from six major consolidated sedimentary old-age aquifers located in the eastern and central parts of the country known as the Arabian Shelf.
This is fossil groundwater, formed some 20,000 years ago. The natural recharge of these aquifers is negligible. The climate of the planet has continually changed over the millennia and some groundwater aquifers are legacies of an earlier climate and are not being recharged. The Arabia Shelf aquifers are groundwater systems that have no natural recharge; unless they are artificially recharged they have a limited life span. If the water from a groundwater basin is used faster than it is recharged, it is being used up and ultimately it will run out, we may be much closer to that point than has been commonly thought.
According to the Water Atlas of Saudi Arabia there are 67 trillion gallons of proven water reserves calculated at some unknown year though thought to be in the last years of the 20th century. Leave it to the Saudis to calculate reserves of water. However, estimates of water stored and what is economically available to use are open to question. In truth, we do not yet know how much water is truly available in an aquifer, we can only see that the water level is falling and the water content observed by the Gravity Recovery and Climate Experiment (GRACE) and Global Land Data Assimilation System (GLDAS) is decreasing.
Recent work has documented that Saudi Arabia and significant segments of Earth's population are consuming groundwater more quickly than it is recharging without knowing when it might run out. Worldwide groundwater still is largely unregulated and unmanaged. Potential consequence when an overused aquifer can no longer supplement limited water supplies are starvation, war and death.
In 1975 it was estimated that Saudi Arabia was using less than 500 billion gallons of water a year for irrigation and a similar amount of water for industry and domestic use. Then water consumption and use changed dramatically. Driven by a government policy in support of achieving food security Saudi Arabia began using groundwater sources for irrigation and growing wheat and grains in the dessert. By 1980 the artesian wells that had fed the oasis’s ran dry, and at its peak in 1999-2000 pumped almost 5 trillion gallons of water in a single year for agricultural irrigation exporting wheat to its neighbors.
At this point it had become clear that the Kingdom was sacrificing water security for food security and policies began to change. However, change was slow because the farm price for water or its availability did not reflect its scarcity or limit. For fifteen years Saudi Arabia has fought to reverse the agricultural and water policies of the last century during which time, it is likely that most of the “proven” groundwater reserves in the Saudi Arabian aquifers has been used up.
The Ministry of Water was created to contain part of the Ministry of Municipal and Rural Affairs and part of the former Ministry of Agriculture and Water. This new ministry was responsible for supervising the water sector, developing water related policies, and setting up mechanisms and programs aimed at managing the water resources in a sustainable way. In 2004 the Ministry of Water also became responsible for the electricity sector and was restructured as the Ministry of Water and Electricity to coordinate the development of water desalination and electricity production. The Ministry of Water and Electricity has been reversing the ill-conceived agricultural policies of the 20th century. This year Saudi Arabia will rely almost entirely on imported wheat. Saudi Arabia who once exported wheat grown using precious groundwater from the Arabian Aquifer System can sell oil for grain and an economic interest in international agri-businesses and use technology to recharge their groundwater reserves-not every nation has that option.