Colorado Water

Colorado receives less than 20 inches of natural precipitation each year most areas, so most of the state requires irrigation to grow crops or to support urban landscapes. In the high mountain areas, which generally receive more than 20 inches of precipitation, almost all of the precipitation falls as snow. Therefore, Colorado’s water supplies are primarily snow melt runoff.


Colorado’s major rivers include Colorado River, Rio Grande, Arkansas River, and South Platte River. Major lakes include Grand Lake, Blue Mesa Reservoir, and the John Martin Reservoir.


While the state’s river systems generate an average 16 million acre feet of renewable water each year, about two-thirds of this water is obligated to leave the state under various interstate compacts and agreements. In addition, of the 16 million AF, about 80% of the water is on the Western Slope, yet about 80% of the state’s population resides on the Eastern Slope. Most of the irrigated agriculture lands are on the Eastern Slope as well. Colorado also uses renewable and non-renewable groundwater to meet our water supply needs (CO Water Conservation Board 2011).

The Arkansas River Basin drains an area of 24,904 square miles of southeastern Colorado and has experienced growth and is expected to have significant increases in growth in the future. Demands on the limited water resources also will increase as changes in water storage, water releases, and/or transfer of waters within or outside of the basin are likely to occur to accommodate the growing population. Water use and quality within the basin can be affected by land-use changes associated with urbanization and agricultural practices (USGS 2009). Back in May 2011, temperatures heated up a snowpack that were two to three times its normal depth; flooding was "likely" in parts of the high country. Current precipitation is 0” (USGS 2011).

The Blue River drains approximately 680 square miles west of the Continental Divide in central Colorado before flowing northward into the Colorado River near Kremmling, Colorado. The Blue River watershed (BRW) is almost entirely located in Summit County and includes the towns of Breckenridge, Dillon, Frisco, Montezuma, and Silverthorne. Dillon Reservoir and Green Mountain Reservoir are major water storage facilities in the watershed. Ski resorts such as Arapahoe Basin, Breckenridge, Copper Mountain, and Keystone have brought rapid population growth and increased tourism and development to the area. In the last seven days, this area collected 0.28” of precipitation (USGS 2011).

The Eagle River drains approximately 970 square miles west of the Continental Divide in central Colorado before flowing into the Colorado River. The Eagle River watershed (ERW) is located primarily within Eagle County and includes the towns of Vail, Minturn, Avon, Edwards, Eagle, and Gypsum. The eastern boundary of the ERW is drained by Gore Creek, located at Vail Pass. Gore Creek flows along I-70 through the town of Vail before its confluence with the main stem Eagle River near the town of Minturn. The Eagle River continues to flow along I-70 to its western boundary near Dotsero. The annual precipitation for this area is 11” for rain and 54” of snow; town of Vail currently has 300” of snow (Eagle County 2011).

The Upper Gunnison River Watershed, located in the Rocky Mountains 150 miles southwest of Denver, Colorado, drains approximately 3,965 square miles. Forest and rangeland comprise 89 percent of land within the watershed, but the traditional western ranching economy is increasingly supplemented through a tourism economy centered around Crested Butte Mountain Resort and the Curecanti National Recreation area. Recreational development and population growth in recent years have the potential to affect both the quantity and quality of water. According to the Water Information Program back in June 2011, The Denver Post posted a report that the Rocky Mountains' winter snow is gradually being replaced by spring rain, and it's likely to get worse in the decades to come (Waterinfo 2011).

As large-scale energy development continues in the Piceance Basin, there is potential for changes in surface-water and groundwater resources. In the southern Piceance Basin, a water task force consisting of numerous local governments, municipalities, and energy companies collectively identified the need for a common data repository. In the northern Piceance Basin, similar efforts were underway in approximately the same timeframe. The outcome of these efforts is the combined northern and southern Piceance Basins project and data repository, referred to collectively as "the Piceance Basin."

The entire state of Colorado as witnessed a fairly warm summer with only 0’-2” of rain from September 15-22 2011 (Intellicast 2011). Colorado is split into two different climates due to higher plain and mountain regions. September will be warmer and wetter than normal and October will be cooler and drier in the higher plains. The mountain regions will experience winter temperatures of above normal, especially in the south, with the coldest periods in early and late December and mid- and late February. Precipitation and snowfall will be above normal in the north and below normal in the south. The snowiest periods will occur in early November, mid-December, mid-January, and early and late March. April and May will be much cooler and snowier than normal. Next summer will be hotter and drier than normal in the north and cooler and wetter in the south. The hottest periods will be in early July and much of August. Colorado is going through a dry year with not precipitation (Almanac 2011).

References:

Colorado Water Conservation Board. 2011. Water supply planning. http://cwcb.state.co.us/water-management/water-supply-planning/Pages/main.aspx (accessed September 22, 2011).

Eagle County. 2011. Quick facts. http://www.eaglecounty.us/localinfo/Quick_Facts/ (accessed September 22, 2011).

Intellicast. 2011. Weekly precipitation. http://www.intellicast.com/National/Precipitation/Weekly.aspx (accessed September 22, 2011).

USGS. 2009. Arkansas River water-quality data. http://rmgsc.cr.usgs.gov/cwqdr/Arkansas/index.shtml (accessed September 22, 2011).

USGS. 2011. Blue River water-quality data. http://rmgsc.cr.usgs.gov/cwqdr/Blue/index.shtml (accessed September 22, 2011).

USGS. 2011. Eagle River water-quality data. http://rmgsc.cr.usgs.gov/cwqdr/Eagle/index.shtml (accessed September 22, 2011).

USGS. 2011. NWIS. http://waterdata.usgs.gov/co/nwis/current/?type=precip&group_key=basin_cd&search_site_no_station_nm=Arkansas%20River%20&site_no_name_select=station_nm (accessed September 22, 2011).

USGS. 2011. Piceance Basin water-quality data repository. http://rmgsc.cr.usgs.gov/cwqdr/Piceance/index.shtml (accessed September 22, 2011).

USGS.  2011. Upper Gunnison River water quality data. http://rmgsc.cr.usgs.gov/cwqdr/Gunnison/index.shtml (accessed September 22, 2011).

USGS. 2011. Water storage. http://www.waterinfo.org/water-storage. (accessed September 22, 2011).