Where do these numbers come from?
In September 1991, the Water Education Foundation published a special report called “Water Inputs in California Food Production” by Marcia Kreith at UC Davis. The study updated numbers issued in 1978 by the UC Cooperative Extension. It examined the amount of water required to produce a range of products (animal and plant based) from the beginning of planting or growth cycle up to the time of cooking. Step by step calculations used to figure the water requirements are included for each food in the 162-page report.
The committee overseeing the study established a number of criteria: the study counted all water – whether naturally available or applied as irrigation water to grow and process food products. No distinction was made between precipitation, surface reservoir water or groundwater. Among several research parameters, an irrigation efficiency of 70% was assumed to be average.
Irrigation is key
Irrigation covers only 20% of the total land use for agriculture but supports 40% of the global fodder output and 55% of the overall, output value. The payoff is a large amount of the world’s available fresh water resources are currently being used for irrigation, in fact 70% of the water being drawn from the world’s rivers, lakes and groundwater aquifers are being extracted for irrigation purposes. Furthermore, other natural resources are required to drive these pumps, highlighted by the fact that 6% of the global electricity consumption was used to power irrigation pumps that feed fields with water.
Doing more with less
Irrigated agriculture, is the sector with, by far, the largest consumptive water use and water withdrawal. To estimate the pressure of irrigation on the available water resources, an assessment has to be made, both of irrigation water requirement, and of irrigation water withdrawal.
Irrigation water withdrawal is the cumulative amount of water withdrawn for irrigation, which largely exceeds irrigation water requirement due to significant losses in distribution and application. Although available for some countries, figures of irrigation water withdrawal are easily confused with agricultural water withdrawal.
There are plenty of ways in which farms can better use our water supply. Through the process of drip irrigation farmers can supply water directly to the roots of their crops rather than sprinkling the water on top. Through properly installed drip irrigation systems, farmers can save up to 80% more water than standard sprinkler irrigation systems. Additionally, by creating ponds and reservoirs, farmers can draw their supply from there, taking the pressure off of local watersheds. Precision agriculture technology, such as field mapping and soil moisture monitoring, can help further save additional freshwater resources through precise placement of irrigated water.
Nearly half of the water currently used in Agriculture is wasted!
Click on the table above to see data from the Food and Agriculture Organization to see data from 165 countries. As is evident from these numbers, much more water is currently abstracted for irrigated agriculture than is required. This precious freshwater resource must be applied in a more effecient manner to ensure both water savings and optimal yields.
Global water use has increased by a factor of six over the past 100 years and continues to grow steadily at a rate of about 1% per year as a result of increasing population, economic development and shifting consumption patterns (UN World Water Development Report 2020). Nearly 70% of the world’s water is used by the Agriculture sector, therefore we can hardly discuss food without acknowledging the water that goes into producing it.
Supply and demand are not equal across the world, and already today water is already a scarcity in many parts of the world. Overall, the world is seriously behind schedule on the UN Sustainable Development Goal No. 6 (SDG 6) to ensure availability and sustainable management of water and sanitation for all. In 2020, 3.6 billion people lacked safely managed sanitation services, 2.3 billion lacked basic hygiene services and more than 2 billion live in water-stressed countries with lack of access to safe drinking water
Water demand cannot exceed water availability. However, while water demand is increasing, water availability is shrinking. In large part because of shrinking surface and ground resources, and ever more so because of pollution. At a macro level, the available surface water resources are forecast to remain about constant, although water quality will deteriorate, and spatial and temporal distribution will change (Wada, 2016). It’s very likely that aquifers will shrink, and salt intrusion in coastal areas will be dramatic. In contrast, the growth of population, gross domestic product (GDP), and water demand will increase globally and unequally. Furthermore, changes will be much more pronounced at the sub-regional level than at the country level, which could lead to conflicts as people desire the same limited resource.
130 gallons per pound
240 gallons per pound
400 gallons per pound
600 gallons per pound
2,500 gallons per pound
Combined with a more erratic and uncertain supply, climate change will aggravate the situation of currently water-stressed regions, and generate water stress in regions where water resources are still abundant today. Physical water scarcity is often a seasonal phenomenon, rather than a chronic one, and climate change is likely to cause shifts in seasonal water availability throughout the year.
Although Agriculture is the biggest consumer of water, many people are not aware of the key role water plays in a number of other sectors. For example the production of clothing, 50% of the worlds textiles are made from cotton. An astonishing 20,000 liters of water is required to produce just one single kilogram of cotton! 1 kilogram is roughly enough to produce one pair of jeans and a t-shirt. The global society will have to make changes to the way we currently use water, considering 2 billion additional people will not only need to be fed by the middle of the century but preferably clothed as well.
TerraRad Tips for saving Water at home
Eating meat once has a water fooprint of 768 gallons/day. Therefore eating more vegetables, try meatless monday, and don’t go nuts.
Recycling cans and plastic bottles saves 30 gallons (110 liters) of water per day!
Recycling paper helps too (4 gallons)
Save Energy, Water and Money
Everything you buy, use and throw away took water to process and transport. Be mindful, use less.
It takes water to make electricity and transportation fuels
It takes energy to move, heat and treat water, so saving energy saves water.
The average American’s water footprint is 1,802 gallons (8,192 liters) of water per day. This includes everything from showers, to outdoor water use, to the water that is required to produce the food that our pets eat. surprisingly little of overall consumption is used for cleaning and cooking. There is a water calculator that asks a number of questions about your lifestyle, and is a cool tool to highlight where much of the daily water requirements come from, there are many hidden sinks in our day to day lives (Water Calculator).
However, the calculator also highlights what day to day activities actually save water, for example, recycling anything from paper, plastic to cans and bottles is actually a water saving phenomenon. My personal water footprint was 1,892 gallons (8,601 liters) per day. Not surprisingly my proclivity for updating my wardrobe had a large impact on my water footprint. Tools like this can help educate consumers and highlight areas in which we can make a change now to better help save valuable natural resources for the future.
Striving to Save Water
We all must come together and take the necessary steps to reduce our individual water footprints. There are multiple resources, to educate oneself on how to save water in our day to day activities and highlights areas that are often forgotten in the fight against diminishing water resources