Water restrictions have been enacted in many cities and regions in Australia, which is the Earth's driest inhabited continent, in response to chronic water shortages resulting from the widespread drought. Depending upon the location, these can include restrictions on watering lawns, using sprinkler systems, washing vehicles, hosing pavement, refilling swimming pools, etc. Overpopulation, evidence of drying climates, coupled with corresponding reductions in the supply of drinking water has led various state governments to consider alternative water sources to supplement existing sources, and to implement "water inspectors" who can issue penalties to those who waste water. Many states describe the different levels of water restrictions in terms of "stages": starting at Stage 1, for the least restrictive, going up as far as Stage 8. The highest level reached in the current drought has been stage 7 for Kingaroy. There are different definitions given to each "stage" in different states.