Water Planning | Water Supply Status

Wholesale Water Purchase

Cascade currently utilizes a combination of member groundwater supplies and regional supplies purchased on a wholesale basis to meet the water needs of its members. Cascade has entered into long-term wholesale water purchase contracts with Seattle Public Utilities (SPU) and Tacoma Public Utilities (TPU). This combination of supply sources enables Cascade to meet the forecast water demands of its members through 2040.

Seattle Public Utilities Agreement

In 2003, Cascade entered into a “block” contract with SPU for the sale and purchase of potable water.  In 2013, Cascade and SPU amended this contract to provide for a block supply of 33.3 MGD (average annual day) through 2039 (through a combination of the original block and varying amounts of supplemental supply).  After that date, the available block declines by one MGD annually until 2064, when 5.3 MGD will remain available from SPU through 2075.  The amended contract will be reviewed and can be modified. 

The original “block” contract between Cascade and SPU (signed in 2003) obligated SPU to provide potable water (and obligated Cascade to purchase it) through 2053.  The quantity through 2023 was 30.3 MGD on an average annual day (additional water is provided during the Peak Season and Peak Month).  The amount of water available then declined in 5 MGD increments every five years, beginning in 2024.  For the last 10 years of the agreement, Cascade would receive 5.3 MGD.  

In late 2008, Cascade and SPU approved amendments to the block contract effective January 1, 2009.  Under that amended Agreement, the Cascade Block would be increased by 3 million gallons per day (MGD) from 2009 to 2017 and 5 MGD from 2018 to 2023 (for a total block of 33.3 and 35.3 MGD respectively).  This supplemental supply was provided at a different rate from the base block.

Tacoma Public Utilities Contract

In October 2005, Cascade and TPU executed an Agreement for the Sale of Wholesale water. Water purchased by Cascade would help fulfill Cascade's supply needs beginning in 2008.

In 2012, Cascade and TPU agreed to amend the wholesale water purchase agreement.  Under the amended agreement, Cascade would make specified supply capacity reservation payments to TPU, in lieu of the minimum purchase payments provided for in the 2005 agreement.  TPU agreed to provide up to 8 MGD of supply to Cascade through 2042.  The amended agreement also provides for Tacoma to sell water supply directly to certain municipalities in connection with the reallocated capital payments that creates an additional means (i.e., substitute water supply) of satisfying Cascade’s obligations to such municipalities arising out of the 2010 agreement between Cascade and the Cities of Auburn, Bonney Lake, Buckley and Sumner.