September 2019: Groundwater levels are continuously decreasing around the world, emphasising calls for active governance and management of extraction practices. Impacts of depletion especially effect rural communities relying on groundwater as their primary source for domestic and agricultural use.
Information
A new study investigates the complex landscape of groundwater extraction, highlighting how global groundwater levels are decreasing. Groundwater is a critical and finite resource and is mainly used extracted for domestic, industrial, or agricultural purposes. Despite groundwater being naturally replenished it is being extracted at a faster rate than can be replaced by rain, rivers, and snowmelts. However, attempts at groundwater conservation such as limiting extraction to certain periods across the year in India have led to knock-on effects such as higher air pollution. Restrictions for irrigation during hot months has pushed back the planting of rice, leading to a later harvest. Farmers now burn crop residue later in the year when the winds are low, causing smoke to linger longer and spiking air pollution. It highlights the complexity of the issue and underlines that all conservation methods should consider system-wide trade-offs such as water conservation and air pollution.
Implication & Opportunity
Excessive groundwater extraction is causing wells to more frequently run dry across the globe, leading to new wells needing to be dug deeper; thus, accelerating groundwater depletion. Additionally, people are digging deeper wells to avoid water sources contaminated by surface activities such as fertiliser runoff from agriculture. Nonetheless, deeper and faster groundwater extraction is costly, requires more energy to pump water to the surface, frequently encounters geological challenges, and salt contents in ground water rise at deeper levels. These challenges especially impact rural communities relying on groundwater as their primary source for drinking water and irrigation. Combatting these challenges may include widespread investments into water infrastructure to avoid spills, water recycling, aquifer recharge practices, less water intense farming and production methods, and active groundwater governance and management at regional, national, and global levels.
Limitations
These studies predominantly focus on groundwater in the US and India, hence the results should be seen within the study’s geographic context and further research is needed in areas with different water resource structures.
Sources
Perrone, D., & Jasechko, S. (2019). Deeper well drilling an unsustainable stopgap to groundwater depletion. Nature Sustainability. Doi:10.1038/s41893-019-0325-z
The Conversation. (2019). Drilling deeper wells is a band-aid solution to US groundwater woes. Retrieved from https://theconversation.com/drilling-deeper-wells-is-a-band-aid-solution-to-us-groundwater-woes-121219
