Temporary water restrictions are short term measures imposed in times of drought or emergency in order to reduce demand and conserve water supply for essential needs. Water restrictions specifically target non-essential uses, such as garden irrigation. Water Corporation requests a temporary water restriction be enacted through the Minister for Water so essential needs are met.
Permanent water efficiency measures (PWEMs) are in place to ensure best practice for the efficient use of outdoor water use. They include the sprinkler watering rosters which are ongoing, rather than temporary. These measures were introduced in WA in October 2007 after a trial and extensive consultation. They are established via regulation administered by the Department of Water, and enforced by Water Corporation.