According to the US Census Bureau there are 312 million people in the United States. As population rises, the demand for fresh water for drinking, domestic use, for industry (especially power generation) and for agriculture increases. The demand for food and the water that is essential to produce food grows with population and wealth. Globally, farming is estimated to account for 92% of water footprint of mankind. Farmers in the United States feed 20% of the world’s population on just 10% of the earth’s surface which has resulted in the United States being the largest virtual water exporter on the globe.
Though “on average” the United States actively uses less than 8% of the water that falls as precipitation within our borders annually, the rain and snow does not fall where needed and when it is needed, our groundwater aquifers are necessary to maintain year round water and supplement surface water supplies. However, we are depleting key aquifers in the United States. In the High Plains that was open range land until the groundwater from the Ogallala aquifer was used to turn the range land into irrigated crops, agriculture is depleting the aquifer because the groundwater within it is predominately non-renewable. In the central valley of California where three crops a year can be grown and crop production is only limited by the amount of water delivered for irrigation, the groundwater is used to increase irrigation waters making up an estimated of 30% of water for irrigation from an aquifer that is also predominately non-renewable. So much water has been pumped that the land above the aquifer- the fine-grained confining beds of sediments- that the land has subsided and can never recover. The water level in both these aquifers has fallen hundreds of feet in the past few generations.
This year it is estimated that the Western United States will ship more than 3.6 million tons of hay and alfalfa whose water footprint is more than 50 billion gallons of water to China this year. We do this in a drought year when the limited water of the Colorado River could be better used elsewhere in the United States and by consuming non-renewable groundwater. Farmers pay almost nothing for water- only what it costs to deliver it, not what it is worth. So, for less than $180 American farmers are selling 13,900 gallons of water to China. This water is both the limited flow of the Colorado and non-renewable groundwater resources.
In many parts of the United States, water resources are limited and strained. Without irrigation even a single crop is impossible with less than 20 inches of rainfall. Yet, we still behave as if water were unlimited and almost free. Irrigated agricultural consumes over 75% or more of the delivered water in California, which produces about half of U.S. grown fruits, nuts, and vegetables. In the United States we have used the various complicated, layered and hidden subsidies within the various water rights arrangements and subsidized water to complicate the business of farming and obscure the true costs of food in America and now we are consuming our non-renewable water resources and subsidizing the water cost for hay and nuts for China. The basic laws and regulations governing water and water rights have not been updated to account for today’s water realities and for recent advances in scientific and technical understanding of the relationship between water, groundwater and ecological services that water perform.
The system of water rights that developed in the west assured for generations the allocation of water to agriculture. The water rights system as conceived and administered in the western states was not designed to conserve water. It was developed in a time when population was still sparse, water supplies were believed to be more than plentiful and development and growth were to be encouraged. The system was designed to protect the water and work necessary to build farms in the west and the government actually encouraged the conversion of over 91% of the range land into cultivated agriculture. This management scheme has resulted in non-sustainable use of groundwater and unsustainable agricultural practices. We are draining the High Plains Aquifer and the Central Valley aquifers though agricultural crop volume per gallon of water has increased over the past generation by adopting more efficient irrigation technologies.
The states of the Colorado Compact need more water. The allocations promised under the Compact were more than 100% of the water available , and the water needs of the states have grown over the years. The water allocated under the Colorado Compact was based on an expectation that the river's average flow was 16.4 million acre feet per year. According to the University of Arizona, a better estimate would have been 13.2 million acre feet at the time of the Colorado Compact and there are indications of periods of mega-droughts in the distant past. During the drought of 2001-2006 the Colorado River flow was estimated at 11 million acre feet and hit a low of 6 million acre feet in 2002. Overuse is killing the Colorado water basin which suffers from decimated aquatic ecosystems, overdrawn and irreparably damaged groundwater aquifers, and polluted agricultural and urban runoff.
California farmers have nontransferable water rights to 20% of the flow of the Colorado River exceeding by an order of magnitude the rights of the state of Nevada. Even with such a large share of the Colorado’s flow California has failed to develop a sustainable water budget. There is little incentive for farmers with senior rights to fully implement water saving strategies- the water is priced too cheap and farmers are unable to sell water rights. By prior appropriation water rights belong to the agricultural irrigation districts despite the changing needs of our nation and a changing understanding of water. The states of the Colorado Compact, the states of the High Plains, and the other major watersheds need to rationalize our water policies and create a sustainable and workable water budget for their communities and our nation as a whole and stop exporting the non-renewable water resources as cheap grains and hay.