Water is a very precious commodity in New Mexico. For example, the capital of Santa Fe gets less than 15” of rain annually, and the entire state gets less than 10” per year. Compare this to Seattle, which gets 38” of rain per year, and Mobile, Alabama which receives an average of 67” per year. And, let’s not forget the ravages of climate change and the reality that the entire Southwest is in the midst of a drought.
Of course, the environment and climate in the Land of Enchantment differ drastically from Washington state and Alabama. Since New Mexico does not get a lot of rain and doesn’t have a multitude of rivers, streams, or lakes, our state depends heavily on groundwater and surface water. About 87% of New Mexico’s public water supply comes from groundwater. As a result, New Mexico and other western states need to draw water from the Colorado River Basin, and unfortunately, demand exceeded supply from that river more than a decade ago.
Last Wednesday, the New Mexico state legislature voted to legalize recreational marijuana, and once Governor Michelle Lujan Grisham signs the legislation as expected, the state will become the 16th state in the nation to legalize cannabis for recreational use. This new industry promises to create thousands of new jobs and millions in new revenue for the state. But we hear in the media quite frequently that cannabis plants need a lot of water, and hence the concern that the cannabis industry will drain our state dry.
Researchers have studied the environmental impacts of water use by cannabis farms, and the notion regarding cannabis as a threat to water resources comes from early case studies of illegal cultivation in watersheds that threatened local aquatic species in the Northwest US. The idea that cannabis is “water-hungry” has shaped water use policy at every government level, but the good news is policies continue to evolve with ongoing research of sustainable and environmentally sound cannabis cultivation practices.
Cannabis farms in other states that rely on surface water must either develop storage, reduce water demand, or seek alternative water sources, such as groundwater. Research of legal cannabis farms has shown that the majority of these farms are using groundwater wells instead of surface water diversions. Some critics may say that cannabis farms would compete for groundwater resources in New Mexico.
One solution for New Mexico would be to enact guidelines for saving and recycling water. This can be done by minimizing runoff from plants, using reverse osmosis technology to recycle any runoff, selecting soils such as perlite and vermiculite to improve water retention, recycling water and using hydroponic cultivation methods. Some growers use aeroponics, which is the process of growing plants in an air or mist environment without the use of soil or a similar medium. Aeroponics uses about 98% less water than traditional methods because the water is recycled throughout the system.
As more and more states move to legalize recreational cannabis, and as the industry continues to evolve, more research is needed to understand the impact of cannabis farming on groundwater wells and surface water diversions. However, I am optimistic that New Mexico can put into place sustainable growing practices that can conserve our state’s most precious resource, water.
Thanks to Thomas Campbell for editing this post.