- One acre-foot of water (the measure typically used to quantify water rights) = 325,851 gallons.
- Stream flow is generally measured in cubic feet per second (CFS).
- 1 cubic foot = 7.48 gallons; thus 1 CFS = 7.48 gallons per second
- 1 CFS = 448.8 gallons per minute = 1.98 acre- ft/day = 722 acre-ft/year
- One million gallons per day = 1.55 CFS = 3.07 acre-ft/day = 1120 acre-ft/year
- Nationwide, an average single-family home connected to a municipal water supply system and paying for water from that utility uses around 166 gallons of water a day. This equates to 5000 gallons of water per month, 60,000 gallons per year, or 0.18595 acre feet of water per year.
- 5000 gallons of water use/day (the amount allowed under a permit exempt well in Washington) equates to 1,825,000 gallons/year, or 5.6 acre/feet/year.
- Use of public water costs nothing for permit exempt wells and holders of individual water rights. In contrast, customers connected to a water system pay for use of water.