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Water Resources

Water Banking

Making Water Available for new uses: both in stream, and out of stream.

In Washington state, water banking is fairly new.  It is a way to use the market to make water available for new uses, such as increasing stream flows and providing water for development.  In 2003 legislation was passed to allow banking in the Yakima basin using the state Trust Water program.  During the 2009 legislative session Chapter RCW 90.42 was amended to clarify that this tool is available to use for banking statewide.  Most of the banking in our state uses the State Trust Water program as the vault to hold water so that it does not relinquish.

What is Water Banking?

Water banking is an institutional mechanism used to facilitate the legal transfer and market exchange of various types of surface, groundwater, and storage entitlements.

The term “water banking” is widely used to refer to a variety of water management practices. In general, no single or common definition exists for water banking, probably because there are such a wide range of approaches to water banking. The term “water banking” is increasingly being used within the water sector to describe other types of water management strategies that extend beyond the traditional definition.

How Water Banking Works

Although banking approaches may differ, the common goal is to move water to where it is needed most. Generally, water banking functions better at the regional or watershed level, rather than at a statewide level. This is because it is difficult both physically and legally to transfer water to new uses outside of the basin the right originated in.

Banking is facilitated by an institution that operates in the role of broker, clearinghouse, or market-maker:

  • A clearinghouse serves mainly as a repository for bid and offer information.
  • Brokers connect or solicit buyers and sellers to create sales.
  • A market-maker attempts to ensure there are equal buyers to sellers in a market.

Many banks pool water supplies from willing sellers and make them available as credits to willing buyers.

Yakima River Basin Water Exchanges

There are water exchanges serving the Upper Kittitas, Lower Kittitas, and Central and Lower Yakima basins, to help secure water for your needs.  Mitigation is only required by rule for the Upper Kittitas.  However, since the early 1990’s permits for new uses of groundwater have required that the impacts are mitigated.

Mitigation plans that effectively offset the impact to the Yakima River of consumptive groundwater uses (those that diminish the amount of water from the source) help ensure that new groundwater uses will not be interrupted during times of water shortage.

Other Washington Water Exchanges


Central Regional Office
Kelsey Collins (Lead)
Department of Ecology
15 W Yakima Ave, #200
Yakima WA 98902

Water Banking Projects

Dungeness - WWT
Yakima River Basin - Ecology
Walla Walla - CBWTP
Walla Walla - WWT

Focus on Water Banking

Focus on Water Banking

Focus on Water Banking Legislation

Water Bank and Exchange Provisions: ESSB 5583 - Effective July 26, 2009
Summary of Bill by Peggy Clifford, WR-HQ

Reports to the Legislature - Water Banking

2012 Report
2010 Report
2008 Report
2006 Report
2004 Report

Water Banking Workshops

Workshop materials

Analysis of Water Banks in the Western States

The July 2004 report “Analysis of Water Banking in the Western States”