Two summers ago I got my first taste of Colorado outdoors. During the Fourth of July weekend my boyfriend and I went on a road trip through Colorado where we camped, hiked and river rafted. The Arkansas River was flowing with mountain runoff after a long winter that covered the Rockies with snow.
Last year, the scenario was different. Rivers were low and the state experienced an extremely dry summer, which peaked in a tremendous wild fire in southern Colorado. The drastic change reflects the transformation that the environment is undergoing.
Climate change will have a significant impact on water supplies in the coming decades.
Water shortages imminent?
According to a National Geographic article, if the earth warms just a degree or two Celsius, regions that depend on runoff from mountain snows for drinking water and farming will face water shortages.
Colorado is no exception. Denver Water representative Travis Thompson, who SolarChargedDriving.Com interviewed for this four-part series on climate change and water, explains: “The water system is a part of the climate system. As one changes, the other will respond.”
As we see temperatures rising and less snow in the mountains, states reliant on mountain runoff and the Colorado River will feel the impact of water shortages.
According to a study by the Colorado Water Conservation Board, peak stream flows in the Western United States are occurring earlier in the spring due to warming temperatures during spring months.
Dr. Michael Kerwin, a geology professor at the University of Denver, explains how earlier mountain runoff in the Rocky Mountains affects water resources.
Lower stream flows
“Normally the spring runoff would happen sometime in May, recently in the past decade that spring runoff is completely done by May,” says Kerwin. “What that leaves is just drier streams in the summer time, less water flowing into the reservoirs, and over time what happens is you decrease the amount of snowfall and the amount of stream flow and so you begin to undertake this long term process of having less fresh water available.”
Temperature increases alone, without any change in precipitation patterns, could dramatically decrease water supply and increase water use.
--Travis Thompson, Denver Water Representative
The concern with earlier spring runoffs and a decreasing amount of snowpack elevates when cities such as Denver are almost completely or 100 percent dependent on snowmelt. Kerwin notes that “although Denver itself is not as concerned with water resources, downstream states certainly are, as the amount of snow and runoff decreases.”
Earlier spring runoffs, however, are not the only concern. The distribution of water, and water use also affects water resources, especially when temperatures rise.
Thompson notes that rising global temperatures could have a large impact on water supplies for Denver.
22 percent less water
“Temperature increases alone, without any change in precipitation patterns, could dramatically decrease water supply and increase water use. A five-degree Fahrenheit temperature increase could decrease supply 22 percent and increase water use by 20 percent,” he explains.
Agriculture accounts for much of the water used on the Front Range and in Colorado generally. Statistics from a University of Colorado at Boulder Study show that about 90 percent of all water usage in Colorado goes to agriculture; the rest is divided amongst households, businesses and industry.
Colorado water rights are mostly owned by farmers, which often dump water onto their fields simply to conserve their water rights, according to the documentary film Blue Gold: World Water Wars.
According to the documentary, the U.S. farming community started tapping into aquifers at a time when there really wasn’t a lot of demand for water. The documentary notes that the law states that farmers are allowed to use limitless quantities of water, but if they don’t use all their water they may lose their water rights.
Single-family households are the next largest user of water in Colorado. Thompson notes that 48 percent of Denver's water goes to single-family homes. 55 percent of this water is used for landscape irrigation, 11 percent for in toilet usage, nine percent to wash our clothes and eight percent for showering.
Growth strains water resources
As population grows in the state of Colorado, constraints on water demand increase. Thompson notes that, “If demand increases and supply availability does not, then our system is more vulnerable to drought.”
More people mean more water use, notes Kerwin.
“Population growth is probably the most important factor when it comes to water resource demand, distribution and availability,” he says. “Denver is projected to double its population by the year 2058 and with our current consumption of water, which averages 189 gallons of water a day, if you double the amount of people to the equation, that is a lot of water. When you couple climate change and the possibility of returning to drought, there is real need to look into this and how we are going to distribute water.”
Although the West is just one U.S. region prone to drought and water shortages, the issue of water and the depletion of water resources is an international problem.
World Health Organization statistics show that a lack of water to meet daily needs is a reality today for one in three people around the world.
And back here in Colorado, going river rafting like I did two summers ago might not be a possibility here in Colorado in the future because of potentially lower river stream flow and the changes in our environment. Experiencing nature might never be the same if we fail to mitigate the impact of climate change on water sources and our environment.
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