Washington water law protects your water resources

100 years of water law

A graphic of Washington, reading
Did you know today marks the 100th anniversary of Washington’s first water law, the foundation for how we manage water resources?

That's right! On June 6, 1917, the newly adopted Washington Water Code established “prior appropriation” as the means for establishing rights to surface water — rivers, streams, springs, or lakes. This means that anyone applying for and receiving a water right first has priority over those applying later. This tenet of water law is known as “first in time, first in right.”

The new law recognized that water is essential for life but not an unlimited resource. No one owns our water resources. They are held in common by the citizens of Washington and under the prior appropriation doctrine, you must obtain a water right to use the waters of the state. And, importantly, new water users cannot impair (which is a legal term meaning to “cause harm”) the water rights of others who already have water rights.

Since 1917 the water code has governed the work of Washington state to ensure that adequate water supplies are available now and into the future for our homes, farms, industries, and natural environment.

Other state agencies managed water until the Legislature gave the assignment to the Water Resources Program when it created the Department of Ecology in 1970. But much has changed in water management since 1917. Over the past 100 years, water law has evolved because of court decisions related to conflicts between water users, the role of tribal treaty rights, and environmental concerns that have increased protection for important fishery resources and species threatened with extinction.

Commemorating the anniversary

We’re using this centennial to invite all Washingtonians to learn more about water law and the importance of protecting water resources.

Washington's water law is complex. To help people better understand the state’s water law and what it may mean to them, we are developing a four-part video series. You can watch the first one, about the history of water law, on our 100 Years of Water Law webpage.

The other videos will address where water comes from, how it is managed, and the implications of climate change. We will use our website and other social media about the past, present, and future of water management in our state.

Join us in our recognition of this anniversary. Visit our webpage and stay tuned for more!