SWSI identifies future Colorado water shortfalls
At the turn of the century, Colorado embarked on a bold new water supply planning process.
Colorado entered the new millennium on the heels of the largest population growth in the state’s history, but this growth coincided with a relatively wet cycle. All this changed at the end of the 1990s and the first years of the new century saw the onset of a severe drought. In some areas of the state 2002 was the driest year in recorded history.
This was the impetus for the 2003 Colorado General Assembly to authorize the Colorado Water Conservation Board (CWCB) to implement the first Statewide Water Supply Initiative (SWSI). CWCB, governed by a citizen board, is the state’s water policy agency with the mission to conserve, develop, protect, and manage Colorado’s water for present and future generations. SWSI was an unprecedented effort for the CWCB. Never before had Colorado developed such a comprehensive picture of our water future. Never before had CWCB assembled all water users – farmers, ranchers, municipalities, industrial users, recreationalists, and environmentalists – to look at the state’s water supply future. SWSI identified Colorado’s current and future water needs and examined a variety of approaches to meet those needs. SWSI culminated in 2004 with the first SWSI report (SWSI 1).
However, by design, SWSI was an “initiative” not a “report.” CWCB intended for SWSI to continue and be the basis for Colorado’s water supply planning process. In 2006, the report was supplemented by SWSI 2 which added technical work on water conservation, alternative agricultural water transfers, environmental needs, and options and strategies for meeting the municipal water supply “gap.”
The SWSI process implemented a collaborative approach to water supply planning by establishing “basin roundtables” – diverse groups of people who provide input on water issues. The basin roundtables established a grass roots effort for education and collaboration. These efforts were institutionalized in the Colorado Water for the 21st Century Act of 2005. The Act created nine Basin Roundtables – one for each of the state’s major river basins and one for the Denver Metro area. The Act charges the Basin Roundtables to develop consumptive and nonconsumptive needs assessments and to propose projects and methods to meet those needs.
In 2010, CWCB updated its analysis of the state’s water supply needs with SWSI 2010. The SWSI 2010 update relies on the Basin Roundtables need assessments and can inform local and regional water planning efforts. SWSI 2010 found that Colorado faces a shortage of water for meeting the state’s consumptive and nonconsumptive water needs. In order to meet Colorado’s water needs, a mix of local water projects and processes, conservation, reuse, agricultural transfers, and the development of new water supplies should be pursued concurrently. If Colorado does not implement a mix of solutions, but rather relies on the status quo, Colorado will lose an unacceptable amount of irrigated agricultural.
SWSI 2010 also included a number of Key Findings in specific areas.
Agricultural Demands — Each basin faces continued shortages associated with existing agricultural demands. There are pressures to keep agriculture economically viable; however, the state could also face a significant decline in irrigated acres by 2050 due to urbanization, water transfers, and market pressures.
Municipal Demands— Colorado’s population is projected to nearly double to between 8.6 and 10 million people by 2050. The Front Range of Colorado will continue to be the most populous place in Colorado with over 80 percent of the state’s population, but the West Slope of Colorado will grow at the fastest rate of any area in Colorado. Colorado will need between 600,000 and 1 million acre-feet/year of additional municipal and industrial water by 2050. This accounts for an 18 percent decrease in per capita water (the amount of water each person uses) demands since 2000; however, the cause and permanency of these conservation savings is uncertain.
Supply— Supplies are not necessarily where demands are and localized shortages exist, especially in headwater areas. Colorado River compact entitlements are not fully utilized. In the South Platte, Arkansas, and Rio Grande Basins unappropriated water is extremely limited. In addition to meeting future municipal and industrial water needs, the South Metro area and northern El Paso County will need to replace approximately 35,000 acre-feet/year of nontributary groundwater with a renewable water supply.
Environmental/Nonconsumptive Needs — Environmental and recreational values will continue to be important to the state’s economy and quality of life. Environmental focus areas were identified on 33,000 miles of streams and lakes in the state with water related environmental and recreational values. Nearly one third of these focus areas have an identified project or method to support one or more of the nonconsumptive values in the area.
Local Water Projects—Local water projects, if successfully implemented, have the ability to meet some, but not all of Colorado’s 2050 M&I water needs. Implementation of these local projects is critical to meeting Colorado’s future water supply needs.
Municipal and Industrial (M&I) Gap — Colorado faces a significant M&I water supply gap in 2050. This gap is defined as the difference between the projected M&I water demands and supplies from existing sources and local water projects. The M&I gap varies between 190,000 and 630,000 acre-feet depending on the success rate of the local water projects.
SWSI 2010 concluded with the following overall recommendation:
With the 2010 SWSI update, CWCB has updated its analysis of the state’s water supply needs. CWCB, the IBCC, and Basin Roundtables are now in an implementation phase to determine and pursue projects and methods to help meet the state’s consumptive and nonconsumptive water supply needs. This will be accomplished through the implementation of the SWSI recommendations by the CWCB.
More information is available at http://cwcb.state.co.us/water-management/water-supply-planning/Pages/SWSI2010.aspx.