Curtailing Water Use

2016 Contacts

For questions and more information on water use restrictions, contact the appropriate Ecology office

Last revised: May 11, 2016

As we do most years, Ecology is curtailing irrigators water use around the state because of declining stream flows.

Why does Ecology curtail some water uses?

Ecology restricts or curtails junior or interruptible water right holders in their withdrawal of water from a river or from groundwater for two reasons:

Curtailment is typically done by limiting the days the junior water right holders can withdraw water from a river or from groundwater.

How does the curtailment notification process work?

The general notification process for irrigators' with junior and interruptible water rights is:

  1. The irrigators may receive a forecast (“heads-up”) letter that they may have to stop using water at certain time.
  2. When curtailment in their basin becomes necessary they receive a cover letter, or are personally contacted by a water master or stream patroller, with an with an official curtailment order or notice that in some cases provides them with a hotline number.
  3. In some cases, they must call the number every day and listen to the recorded message which lets them know if they can withdraw water on a particular day.

What is an instream flow rule and why is it important?

An instream flow rule establishes specific stream flow levels that will protect and preserve adequate water in streams for people and the environment.  They are like a water right for the stream and all the resources that depend on it.  Instream flows let Ecology know whether there is any water available for new uses.  They protect a stream from future withdrawals.  For more information see:

What are interruptible water rights and why can they be curtailed?

A water right is a right to use water, not a property right.  A right to use water is determined by its priority date.  Under Washington’s “first-in-time, first in right” legal framework, a person who established a water right first has a senior water right.  This gives them the right to withdraw all their water before the next person in line, who holds a right “junior” to their senior right.

In any river basin, the water use of junior water right holders can be interrupted if they are impairing the water use of senior water right holders, or there is a risk of impairment because a water source is insufficient to meet all the water demands on it.

Other resources: