Enhancing groundwater security in the United States
Recommendations from the President’s Council of Advisors on Science and Technology
24 Jan 2025 by The Water Diplomat
In December 2024, the President’s Council of Advisors on Science and Technology submitted a report to the White House which made a series of recommendations in response to the groundwater challenges of the United States. The President’s Council of Advisors on Science and Technology (PCAST) was established in 2001 as a scientific and technical body mandated to provide advice on technology and scientific research priorities directly to the President. The report on groundwater was prepared by an inter-university working group and reviewed by PCAST members prior to its release.
An initial key conclusion of the report is that the United States is currently facing serious and unprecedented groundwater risks: in many aquifers groundwater withdrawal is outpacing the rate of natural recharge. Daily water demand in the United States is some 1million megalitres, of which 29,3% is supplied by groundwater. The agricultural sector accounts for the largest withdrawal of groundwater, at 70% of the total. Groundwater resources in the western United States, in particular, are being depleted at significant rates, primarily as a result of agricultural withdrawal. Beyond this, groundwater provides drinking water for half the US population as well as for the great majority of rural areas.
In the period since 2003, groundwater supplies have been in decline across much of the southern United States. The PCAST report states that is leading to significant drops in the water table, increased pumping costs, and negative impacts on surface water bodies and ecosystems. An additional challenge is that in the United States, the rate of recharge of aquifers in itself is low in many cases, as many aquifers are so called ‘fossil aquifers’. These are aquifers in which water was deposited many thousands or even millions of years ago, often in different climatic conditions to those experienced today. Much of the water in the major aquifers of the United States, the report states, is fossil water, and this water is being depleted at alarming rates, especially in the western parts of the U.S. However, this information is pieced together from different measurements and reports about individual aquifers and river basins: the country lacks information that is whole-of-country, comprehensive and timely.
By the same token, the Federal Government has limited authority to regulate groundwater. Federal groundwater management has focused primarily on the quality if groundwater sources of drinking water. Federal government does also have programmes in place to encourage sustainable water management practices. However, on the whole, groundwater governance is decentralised, with each state largely responsible for the development of laws and policies. This has led to a complex mix of policies and regulations whereby in some areas, groundwater is closely regulated and in others, it is not. Many States, such as Arizona, California, Idaho, Kansas, New Mexico and Texas, have introduced statewide actions to monitor and conserve groundwater. However, there appears to be a regulatory gap with respect to Native and Tribal communities which are faced with water scarcity, contamination and lack of access to drinking water. Here, collaborative frameworks are required to enhance partnerships between tribal nations and different levels of government.
Recommendations
On the basis of the analysis presented, the Council of Advisors put forth a number of key recommendations to improve groundwater governance.
The first recommendation is to improve the evidence base for decision making: PCAST recommends a whole-of-country, unified and comprehensive picture of the nation’s groundwater storage, withdrawal and recharge. There is currently an insufficiently clear picture of how much groundwater there is, how fast it is being depleted, and how rapidly it is being replenished. This requires improvements in collection and synthesis of data on groundwater across the country. It also requires the development of decision support tools within a holistic national modelling framework.
The second recommendation is to establish research programmes which can put forward technologies and strategies for the safeguarding of groundwater supplies both in quantity and in quality. his requires research towards a national overview of the chemical composition of groundwater. Research is also needed on technologies for groundwater monitoring, recharge, conservation and reuse, as well as on sustainable utilisation of groundwater.
This leads to the third recommendation, which is to establish a nationwide network of ‘groundwater engagement hubs’ which can provide technical assistance in planning sustainable groundwater use - including in tribal areas.
The fourth recommendation is to create a competitive grants programme for institutions managing linked surface and groundwater sources to encourage evidence-based decision making, sustainable withdrawals, and a focus on restoration that involves managed aquifer recharge.
The fifth recommendation is related to the value attributed to groundwater: PCAST recommends including groundwater resources within a framework of natural capital accounting. This framework attributed value to the nation’s natural assets and provides a frame of reference for economic decision making across national government.
The sixth recommendation focuses on staff and capacity: addressing the challenges of groundwater requires a scientifically and technically proficient workforce, and therefore the Council proposes a campaign to recruit, develop and retrain a skilled workforce in groundwater science, management and stakeholder engagement.