New Mexico is a desert biome subject to drought, a place where water is a sacred commodity. Monitoring residential usage while ensuring equitable dispersal of water are common concerns in our region. New Mexico directs 78 percent of its water budget exclusively to irrigated agriculture. According to the Office of the State Engineer, livestock account for just one percent of all water use. In this context livestock are not directly credited with the entirety of their water footprint, which includes the water utilized to grow alfalfa and other grasses/grains dedicated to feeding them. Animal agriculture is unsustainable not only from a perspective of water consumption, but also in terms of energy efficiency (calorically speaking). Regardless, the full extent of animal agriculture’s water consumption should be of our greatest immediate concern.

Summary of Estimated Water Use in the United States in 2005 from the USGS. Showing water withdrawn nationally by category.

The full scope of livestock and dairy farming’s water usage cannot be observed from a surface view. The direct water usage of livestock typically expressed in data sets include drinking water, service uses (e.g. sanitization of slaughterhouses), and for mixing into feed. For example, according to a USGS 2005 summary on estimated water usage, livestock account for only one percent of water withdrawal in the United States. Additionally, agricultural data for irrigated crops tends to be inclusive, confounding animal forage with consumer crops. Therefore, people may assume that our water is primarily applied to plant-based foods intended for direct human consumption.

“Although it is known that animal products are very water intensive, little attention has been paid thus far to the total impact of the livestock sector on the global demand for freshwater resources.”  

Despite these assumptions, the impact of animal agriculture is quite water intensive – especially the industrial/commercial animal industries. However, there are varying types of production systems that use different sources of water. Industrial systems such as CAFOs (Concentrated Animal Feeding Operations) use significantly more concentrated feed requiring more “blue water,” the volume of surface and groundwater consumed, factoring in evaporation losses. Whereas, grazing systems rely primarily on “green water” (rainwater), due to livestock’s consumption of roughages (undomesticated vegetation) as their primary feed. The water footprint of concentrated feed (e.g. grain, corn, or alfalfa) is far greater than that of grazing (or mixed systems).

“Animal farming puts the lowest pressure on freshwater systems when dominantly based on crop residues, waste, and roughages.”

Grazing is the least intensive method, accounting for only 3.6 percent of the total global water footprint, mainly for “drinking and service use.” Industrial systems utilize collected rainwater as well, comprising 82 percent of the industrial system’s 22.3 percent of total global agricultural water footprint.

A Global Assessment of the Water Footprint of Farm Animal Products. Mesfin M. Mekonnen and Arjen Y. Hoekstra. This table shows different types of water category withdrawal in cubic meters per ton based on different agricultural systems and types of animal products.

“Beef cattle have the largest contribution (33%) to the global water footprint of farm animal production, followed by dairy cattle (19%).”

The lifetime water usage of cattle is alarming on a global level: during the average life span of beef cattle (3 years), an individual uses 1,899 cubic meters of water, and annually beef cattle collectively use 798 cubic gigameter of water! More strikingly, during the average life span of dairy cattle (10 years), an individual uses over 20,000 cubic gigameter of water. Collectively, dairy cattle annually consume 469 cubic gigameter of water!

A Global Assessment of the Water Footprint of Farm Animal Products. Mesfin M. Mekonnen and Arjen Y. Hoekstra. This table shows average lifetime and annual use of different livestock animals.

Beef requires a hefty 15,415 cubic meters of water per ton of food produced. Dairy products include: butter (5,553 cubic meters of water/ton) and milk (1,000 cubic meters of water/ton). In contrast, pulses (4,055 cubic meters of water/ton) combine to a fraction of the water footprint of beef. Overall, if plant and animal metrics are summed together separately and pitted against each other, plant agriculture demands less water. For example, per calorie of beef produced the water expenditure is 20 times greater than for starches and cereal crops.

“The general conclusion is that from a freshwater perspective, it is more efficient to obtain calories, protein, and fat through crop products than animal products.”

A Global Assessment of the Water Footprint of Farm Animal Products. Mesfin M. Mekonnen and Arjen Y. Hoekstra. This table shows categorical water withdrawal for animal and plant agriculture relating to their nutritional content/value.

So, the inherent trend on a globe scale shows that cattle are demonstrably water intensive and energy inefficient. Then, why would we continue to focus our food industry in New Mexico on dairy and beef cattle rather than on maximizing consumer (non-forage) crops? “Replacing all meat by an equivalent amount of crop products such as pulses and nuts will result in a 30% reduction of the food-related water footprint of the average American citizen.” Thus, we know that plant-based foods are not only healthier for our bodies, but vital to a more sustainable future for our water resources.

-Posted by Tyrel