Since the mid-1990's, drastic changes in water demand have occurred in the region. Water demand has fallen far below even the most conservative planning estimates due to a variety of factors.
Residential water use reported in the
2009 Regional Outlook for utilities in the three-county region shows about a 25 percent decrease in water use per household from 1990 to 2005 for both single- and multi-family residential customers (see figure on page 8). That decrease in average water use per household was primarily a reflection of increased water use efficiency, including savings from utility-sponsored water conservation programs. Commercial and industrial water users have also significantly reduced their water use. Utilities continue to see further declines in water use and anticipate this trend to continue in the future, albeit with small declines expected.
The central Puget Sound region has sufficient water for at least the next 50 years, given considerations of growth in the region and the potential impacts of climate change.
The regional water suppliers are making significant improvements and enhancements to their long-estabilished systems. For example, Seattle is now able to refill Chester Morse Lake to higher levels, providing more water later in the year. Tacom's treatment projects enhance supply reliability. And Cascade Water Alliance, through long-range planning for new water supply sources, purchased Lake Tapps in Pierce County. That additional supply has also led to interdependent arrangements with four neighboring communities around Lake Tapps (Aubrun, Bonney Lake, Buckley and Sumner), ensuring their future water needs are met.
A critical part of supply has been the tremendous value, investments andopportunities already realized by all the utilities. The region's utilities also maintain active conservation programs as part of effective resource management. Attention is currently focused on the scale and timing of existing and future programs. The overall supply in the region is very good.
The Forum's vision is to maximize the use of existing supplies before developing new supplies, which maximizes ratepayer value at lower costs. The region's water leaders are working together to make this a reality.
As suppliers look out 50 years and beyond and work to achieve collaborative and efficient use of available resources, there will be economic opportunities and a competitive advantage provided for the central Puget Sound region because of wise water planning.
The 2009 Regional Water Supply Outlook is a comprehensive assessment of municipal water supply and demand in King, Pierce and Snohomish Counties. The Outlook contains current and projected municipal water demands for each county within the three-county region. It includes an analysis of regional water supplies, and details
of potential future municipal water supply options including enhanced conservation, and wastewater reuse.
The 2009 Regional Water Supply Outlook found that there is currently sufficient water supply to meet the regions reasonably anticipated demands through 2050, including the projected effects of climate change. While there could be shortages beyond 2050 under some conditions - population growth beyond current expectations or climate change without adaptive resource management, many potential additional supplies have been identified which could be developed when needed.
The Outlook found that single-family residential water use has been reduced significantly within the region, dropping from more than 275 gallons per day per household in 1990 to just under 200 gallons per day per household in 2005. Commercial and industrial water users have also significantly reduced their water use as well.
In 2001 the Forum has produced the first 20-year regional water supply assessment, the Central Puget Sound Regional Water Supply Outlook (Outlook). The 2001 Outlook was an extensive assessment of water supply and demand in the three-county area including King, Pierce and Snohomish Counties.
The Outlook gathered information from the 158 largest water utilities that supply water to over 90 percent of the three-county population (estimates were prepared for the remaining areas). It included current and projected water demands (to 2020 for individual utilities, and to 2050 regionally), an analysis of regional water supplies, and details of potential future water supply options. The 2001 Outlook was created to provide a foundation for regional water resource planning and coordination.