Sustainable Groundwater Management for Agriculture

Crop irrigation with groundwater, Carbondale, Colorado. Photo by Brian Richter

I traveled to the World Water Week in Stockholm last week to release a new report that I co-authored with Melissa Ho, the World Wildlife Fund’s Senior VP for Freshwater & Food. The report is entitled “Sustainable Groundwater Management for Agriculture.” It’s our attempt to make a complex subject as simple and comprehensible as possible.

I was surprised at how much I learned by reviewing recent literature about groundwater. There have been some amazing advances in groundwater science and modeling in recent years. Here’s a few key take-aways; I hope you’ll read the report for more!

Of all the accessible fresh water on our planet, groundwater is 30 times more abundant than surface water (rivers & lakes). That makes groundwater an essential resource that must be protected and managed with care.
Shallow groundwater reserves are supporting nearly half of all freshwater ecosystems on the planet, either by nourishing the roots of plants or by draining into rivers, streams, and lakes. When we lower groundwater levels by over-pumping, we dry up these important habitats.
Groundwater supports 40% of all crop irrigation. But nearly a quarter of the irrigated farmland that depends on groundwater is unsustainable because of over-pumping and depletion of groundwater reserves (aquifers).
Poor management of groundwater pumping and associated lowering of aquifer levels is causing many problems:
- Agricultural and drinking water wells are drying up or becoming too expensive to operate as it becomes more expensive to pump water from deeper underground;
- The land surface overlying depleted aquifers is collapsing (subsidence), salty water is being drawn into freshwater aquifers (saltwater intrusion), and there has been widespread ecological damage.

We highlight four proven solutions:

Analyzing groundwater information to develop a sustainable management plan, including monitoring to verify a plan’s efficacy;
Setting clear limits (‘caps’) and allocations for groundwater consumption to ensure balance between extractions and replenishment;
Enhancing aquifer recharge through natural or managed replenishment; and
Reducing extractions as necessary to restore balance with aquifer replenishment