In 1917, the Legislature passed the first comprehensive water management legislation.  Passage of the Water Code established the prior appropriation doctrine in Washington, often known as "first in time, first in right," and created a priority system based on the date of use or intent to use water.  With certain exceptions, new rights to use surface or ground water or to establish reservoir and storage projects must be established according to the permit system.  Exemptions include any withdrawal of public groundwater for stock watering purposes, for watering a lawn, or for a noncommercial garden less than one- half an acre.  Single or group domestic uses or industrial purposes not exceeding 5000 gallons a day are also exempt.

A person seeking a new water right files an application with the Department of Ecology (Ecology), which must consider a four-part test when deciding whether to issue the requested right:

• whether water is available;
• whether a beneficial use of water would be made;
• whether granting the right would impair existing rights; and
• whether the proposed use would detrimentally affect the public interest.

If an application passes this test, Ecology issues a permit which establishes a time table for constructing the infrastructure to access the water and for putting water to beneficial use.  When the conditions of the permit are satisfied, Ecology issues a water right certificate.

Prior to passage of the 1917 Water Code, there were some riparian water rights in Washington.  A riparian right arises by virtue of ownership of the land bordering the stream, lake, or other water body.  The Water Code established that nothing contained in the Water Code shall be construed to lessen, enlarge, or modify the existing rights of any riparian owner or any existing right acquired by appropriation, or otherwise.

The Water Code is amended to establish that nothing contained in the Water Code shall be construed to lessen, enlarge, or modify the existing rights of any riparian stock watering rights.