WCMP, your free irrigation management services provider, is on call to provide you with irrigation services that help improve
irrigation efficiency. Through a cooperative effort between the East Maricopa Natural Resource Conservation District and the Arizona
Department of Water Resources, the WCMP has been established to assist in sustaining production agriculture in the Phoenix AMA.
The WCMP provides water measurement, slope determination, irrigation scheduling assistance, irrigation system evaluations, AG
BMP enrollment, and practical recommendations to help improve irrigation efficiency.
Call today to experience the value of the WCMP 480.466.2968
COMMON IRRIGATION TERMS
Field Capacity = The maximum amount of water that a particular soil texture can
hold
Available Water Holding Capacity (AWHC) = The amount of water in the root zone between plant wilting point
and field capacity
Transpiration = Water movement up through a plant’s roots and the evaporation of
that moisture from its leaves, stems, and flowers
Evaporation = The conversion of a liquid to a gas
Evapotranspiration (ET) = The sum of transpiration and evaporation
Field Application Efficiency (FAE) = The ratio between the amount of water needed to refill the soil
profile and the amount applied
Irrigation Efficiency (IE) = The ratio between the amount of water beneficially used by the
crop and how much was applied
Distribution Uniformity (DU) = How uniformly water is applied to an area being irrigated
Consumptive Use (CU) = The sum of the amount of water lost to evaporation and the
amount of water drawn up into the plant through the roots and
transpiring through the leaves during crop growth
Soil Texture = The proportion of sand, silt, and clay particles that make up a given
soil
Opportunity Time = The amount of time that water is observable on the surface of a
given area
Common Conversions
1 gallon = 8.3 pounds
1 cubic foot = 7.48 gallons = 62.4 pounds
450 gallons per minute (gpm) = 1 cubic foot per second
1 cubic foot per second (cfs) = 1 acre-inch per hour
1 acre-inch = 27,000 gallons = 1 acre flooded 1 inch deep
1 acre foot = 12 acre-inches = 43,560 cubic feet = 325,900 gallons
1 gallon = 3.785 liters = 0.003785 cubic meters
1 cubic meter = 1000 liters = 264.2 gallons
