Water Facts


  • 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.

River Anatomy

American Rivers

Headwaters/river source: The beginning, or source, of a river is called its headwaters. Some headwaters are springs that come from under the ground. Others are marshy areas fed by mountain snow. A river’s headwaters can be huge, with thousands of small streams that flow together, or just a trickle from a lake or pond.

Tributaries: A tributary is a river or stream that feeds into another river, rather than ending in a lake, pond, or ocean. If a river is large, there’s a good chance that much of its water comes from tributaries.

River Channel: A river’s channel is its unique signature, the course it carves across the landscape. The shape of a river channel depends on how much water has been flowing in it for how long, over what kinds of osil, rock and vegetation. There are many different kinds of river channels- some are wide and constantly changing, some crisscross like a braid, and others stay in one main channel between steep banks.

Riverbank: The land next to a river is called the riverbank, and the stream-side trees and other vegetation is sometimes called the riparian zone. This area provides important habitat for birds and other wildlife.

Mouth/Delta: The end of a river is its mouth, or delta. At a river’s delta, the land flattens out and the water loses speed, spreading into a fan shape. Usually this happens when a river meets an ocean, lake, or wetland.

Water Cycle

National Oceanic and Atmospheric Administration