As the saying goes: "Whiskey's for drinking, water is for fighting." This is not far from the truth in Colorado! Water use and water rights are prominent issues in the state. It is an unusual experience for anyone that grew up on or near the East Coast, where the issue of water rights almost never comes up, to move to Colorado and find out that the "average" person is conversant in water rights. Water is such an important issue for Coloradans (and many who live in the western United States) because it is relatively scarce. As you can see in the maps below, most of the state receives under 20 inches of precipitation per year, and in fact, the average rainfall across the state is 15 inches per year, according to Denver Water. This makes most of the state semi-arid, which means that it is climatologically not far away from a desert (arid) environment. As a point of comparison, most of the land east of the Mississippi receives more than 35 inches per year, with State College, PA receiving about 40 inches per year.
Further complicating matters is the comparison of the rainfall and population geographies of the state. Recall that the Western Slope of Colorado lies west of the Continental Divide and the Eastern Slope (including the Front Range) to the east. According to "Water Law" (Denver Water), 10 percent of the state's residents live on the Western slope, but it contains 33 percent of the state's land and 70 percent of its water. Because of this, Western Slope water is often used on the Eastern Slope. This, in addition to relative scarcity and Colorado water laws, has contributed to water being a major issue in the state.
To Read Now
Please read the following summary of Denver and Colorado water policy. Read the sections entitled "Water law," "Water rights," "Rain barrels," and "Graywater use."