In many parts of the world, groundwater reserves are overexploited to such an extent that groundwater levels are being drastically reduced. Regions with intensive agricultural irrigation like the USA, China, Pakistan, South and West India and the Middle East are affected by this situation. But also in Europe groundwater reservoirs are being drained, for example in Spain, southern France, Bulgaria and Greece. “Due to the extreme use of groundwater, especially in dry and semi-dry areas, the so-called compensating buffers disappear”, says ISOE water researcher Thomas Kluge. “As a consequence, lakes, wetlands and rivers are drying up, a problem that is exacerbated by climate change” since rising temperatures increase the rate of evaporation and less groundwater can build up again. “Thus food security is at risk”, says Kluge, “as food production depends on the availability of groundwater supplies. If the use of this resource is not regulated in a sustainable manner, bottlenecks in food production will inevitably be the result.”
International program to stop overexploitation of groundwater resources
Sustainable water abstraction means not to extract more water than can in due time be replenished via the water cycle. “Although legal requirements for groundwater regulation do exist in the countries affected by lack of water, the problem lies in the absence of monitoring”, says water expert Kluge, who recommends a comprehensive data monitoring of the abstracted water quantities in order to attain a regulation that enables to determine rates that ensure the necessary groundwater recharge. This procedure requires the cooperation of authorities and users, which often fails due to ownership structures. Corruption, abuse of power and a poorly developed statehood often also stand against a successful regulation. “These institutional and administrative weaknesses are the reason that even dramatic overexploitations of groundwater reserves are simply being ignored”, observes Kluge. “That is why we need to establish an internationally regulated groundwater monitoring that includes support for modeling groundwater dynamics within the framework of an international program based on the UN sustainability goals”, Kluge stresses.
Groundwater management must become part of the Sustainable Development Goals (SDG)
From a water expert’s point of view, the fossil groundwater reserves which are the oldest and deepest water systems that are not recharged by precipitation, are particularly worth protecting. “These natural water resources are irreversibly destroyed”, says Kluge. In Egypt, the Middle East, Jordan and Libya in particular, the abstraction of fossil groundwater is increasing dramatically. Kluge believes that in order to cope with the worsening groundwater crisis the Sustainable Development Goals (SDG) should be supplemented by a definition of sustainable groundwater management. “In the Sustainable Development Goals, the global community has so far avoided explicit statements on groundwater conservation. The reason for this reluctance lies in the fact that groundwater systems are not limited to a state territory but cross-border systems are affected internationally and complicated negotiations with governments and users, like for instance farmers, would have to be expected”, says the water researcher.
Unregulated irrigation in agriculture leads to soil salinization
Kluge believes that international negotiations are necessary because the consequences of groundwater overuse are as varied as its reasons. In populous Southeast Asia, but also in Iran, Egypt and the Middle East, Kluge sees state subsidization of energy as one of the reasons for the groundwater crisis. By subsidizing diesel and electricity for water pumps, the state offers no incentives to save energy and water. “The result is unregulated irrigation with the help of subsidized energy”, says Thomas Kluge. “In dry-hot areas, this does not only cause water shortages but also salinization problems”, since the evaporation of excess irrigation water causes an increase in the rise of soil-bound salts and crystallization on the surface. “This persistently salinizes the soil and renders the fields permanently useless for agriculture.”
Solutions for groundwater crises and conflicts
But positive approaches do exist. Kluge refers to the Hessian Ried as the only region in the EU that has a legally binding groundwater management plan that regulates extraction volumes. Kluge is certain that participatory management plans are of great importance, also with regard to conflicts concerning the use of resources. These plans can help to reconcile the demands of water management, agriculture, industry, and nature conservation. “In future, a central element of water use must also be the reuse of treated wastewater”, says Kluge. This would have great potential to protect groundwater, which is a highly valuable resource.