Pressure is growing on groundwater throughout the world, especially from agricultural use. A “silent revolution” has been occurring, for a long time invisible but now increasingly manifest. It is essential that we contain it as soon as possible.
To meet agri-business needs in India, a country of 1.3 billion people, groundwater has been suffering relentless extraction by much of the agriculture sector. It is therefore no coincidence that India regularly suffers from droughts. In fact, the water table there has dropped up to 30 meters in a generation, with tragic results on a nearly daily basis. But the situation in India is not an isolated one, as pressure on groundwater is increasing worldwide. This is a “silent revolution”, long invisible but now increasingly manifest. It must be contained as soon as possible.
Increasing and widespread pressure on groundwater
Groundwater feeds the flow of watercourses and helps maintain wetlands, which are reservoirs of biodiversity. But the use of groundwater is increasing because it is generally of better quality than surface water and is available for a variety of uses, occasions, and places. Concern about its overexploitation is growing to the extent that the next UN World Water Development Report, expected in 2022, will be devoted to groundwater.
Exploitation of groundwater for urban and industrial uses is on the rise. In particular, its use in agriculture has soared since the second half of the 20th century, generating both qualitative and quantitative tensions.
About 70% of groundwater extraction worldwide is for agriculture. Moreover, groundwater is used for a growing share (currently about 40%, or more than 100 million hectares) of the planet’s irrigated surface area. In the Maghreb, there is a clear correlation between the growth in the agricultural economy and intensive use of groundwater, which has allowed Algeria, for example, to nearly quadruple its irrigated land between 2000 and 2017. And extractors are engaged in a race to pump groundwater even when they are aware of the risk of resource depletion—pumping that can lead to exclusion for the poorest and aggravation of economic and social inequalities.
Multiple factors driving the race to pump
Groundwater extraction allows farmers to compensate for lack of or insufficient access to surface water. It also frees them economically, socially, and even politically from the constraints linked to surface water collective management via water towers, etc., by the community or the central government. In the Saïss plain in northwestern Morocco, owning a well or borehole equates to “having one’s own water,” which in turn is a question of dignity and allows those owners to free themselves from the hold of the State. The race to pump as a “race to obtain one’s identity.”
Technical progress has enabled significant increase in the flows that are extracted at reduced energy costs. But some public policies also facilitate intensification of groundwater exploitation. For example, heavily subsidized access to energy like fossil fuels encourages farmers to extract even more groundwater if they have boreholes equipped with engines that run on this type of energy. Farmers can also connect to the electricity grid or make use of solar energy (which is developing rapidly around the world) to help them exploit groundwater extracted thanks to this nearly free source of energy.
Other forms of public subsidies, such as agricultural subsidies targeting certain crops, can also intensify groundwater extraction. In Spain, European Union subsidies for olive oil production have had terrible consequences on the La Loma aquifer in Andalusia.
Liberalization of international trade and access to new markets are also playing a decisive role in increased extraction. Production of cereals in the Great Plains of the United States, fruit and vegetable crops in the Mediterranean basin, asparagus in Peru, and grapes in Chile all depend on intensive use of groundwater.
Ideas for limiting the use of groundwater
A number of technical responses are being made to limit agricultural extraction for agricultural use. These include dam construction, hillside reservoirs and use of new irrigation techniques. However, the impacts of these measures are often underestimated.
In the Saïss plain in Morocco, the introduction of drip irrigation has been presented as a source of water savings. However, it has led to a rebound effect: irrigated areas increased by 50% between 2005 and 2014, and groundwater extraction doubled. Meanwhile, there is not necessarily proof that this technology is saving water.
Generally speaking, there are two types of institutional responses: regulation by the public authorities and mechanisms based on participation by all users. Regulation takes the form of regulatory instruments (authorizations, bans, quotas, zoning, closure of wells), economic instruments (taxes, subsidies), or indirect measures linking water to other issues (energy, food security). Participatory mechanisms, on the other hand, seek to involve rights holders through joint management arrangements.
The most promising solutions probably lie in a hybrid use of these two approaches. However, they can run up against difficulties. Water tables, for example, are “out of sight, out of mind,” and any hydrogeological studies that have been made are few in number and rarely shared or circulated. The state of groundwater resources hence suffers from a lack of shared vision, and this is sometimes used as a pretext for inaction.
Monitoring and control activities are also difficult and costly. In fact, extractions can be carried out from any location, without their effects being directly perceived. There are also political obstacles. The political costs of restricting access to resources may encourage governments to focus on short-term economic development at the expense of sustainable resource management.
Recognizing groundwater as a common good
A group of researchers and practitioners has recently set out four principles for joint action to promote sustainable use of groundwater. This editorial acts as their mouthpiece.
The first principle insists on building shared knowledge and representations of how aquifers work. These representations must be socially and politically accepted, and based on easily appropriated indicators. One way to achieve this solution is through observatories. Their actions can be adapted to the needs of long-term monitoring of aspects deemed important for the stakeholders: location of wells and boreholes, monitoring of piezometric levels, qualitative variables, etc. The Indo-French Center for Groundwater Research, based in Hyderabad, India, is a good example.
The second principle proposes to implement knowledge-sharing and negotiation processes whereby divergent interests can be expressed. These must in particular take into account the impacts on the flows of watercourses and on the ecosystems associated with the latter. An interesting initiative is taking place in Senegal, in the Niayes area on the coastline between Dakar and Saint-Louis. There, the government, along with the support from the NGO GRET, is setting up water platforms in local communities. These ad hoc associations unite local stakeholders, helping them to build a shared analysis, a vision for the local community, and local plans for integrated resource management.
The third principle advises focusing on user communities to share responsibilities. Depending on how operational these communities are, they can be entrusted with certain responsibilities in exchange for commitments. In Spain, for example, in the eastern La Mancha aquifer, irrigation users are organized into a users association that has reduced extractions by about 25%. This result has come about notably from reciprocal monitoring of irrigation users and sanction mechanisms, established in conjunction with the authorities.
Finally, the fourth solution encourages the understanding of groundwater as a common good as well as the development of local projects that aid in implementing legitimate regulatory instruments locally. Initiatives along these lines have been carried out around the Crau aquifer (in the Bouches-du-Rhône region of France), where, at different levels, environmental preservation, support for a quality agricultural sector (promoting Crau hay), and drinking water supply issues are combined.
Need for urgent action
As we have seen, many regions are experiencing intensive agricultural use of groundwater resources. The overall trend remains worrying, even if their use potential is not exhausted everywhere (investment in its development in sub-Saharan Africa, for example, has not yet been possible for economic, political, and institutional reasons). This is especially true when we examine the solutions provided up to now, which are proving to be insufficient. Nevertheless, ways of resolving these challenges can be identified, provided that the actors in charge of them agree to take up the gauntlet!
The opinions expressed on this blog are those of the authors and do not necessarily reflect the official position of their institutions or of AFD.