The ability to calculate the typical amount of water needed for a specific task is important in water management planning. Water rights are limited to the quantity of water that can be beneficially used. Here are some water use standards used by IDWR to evaluate water right applications and claims. Typically, applicants and claimants seeking more than these amounts are asked for supplemental documentation explaining the need for more water.
cfs (cubic foot per second) = 448.8 gallons per minute
AF (Acre Foot) = 325,851 gallons
Stock Watering
Cattle, Other Than Dairy – 12 gallons per day per cow
Dairy Cattle – 35 gallons per day per cow
Horses – 12 gallons per day per horse
Mules – 12 gallons per day per mule
Hogs – 4 gallons per day per hog
Goats – 2 gallons per day per goat
Sheep – 2 gallons per day per sheep
Chickens – 5-10 gallons per day per 100 chickens
Turkeys – 10-18 gallons per day per 100 turkeys
Domestic Use Diversion Rates
These figures show diversion rates typical for in-house domestic use. These figures do not include water for domestic stockwater or lawn and garden irrigation. Applicants seeking to divert water in excess of these rates for in-house domestic use should provide information explaining why the additional quantity is needed.
1 Household – 0.04 cfs
2 Households – 0.06 cfs
3 Households – 0.08 cfs
4 Households – 0.10 cfs
10 Households – 0.15 cfs
20 Households – 0.20 cfs
30 Households – 0.25 cfs
40 Households – 0.30 cfs
50 Households – 0.33 cfs
Other Common Uses
Hotels with private bath (two persons per room) – 60 gallons per room per day
Motels with bath – 40 gallons per day per bed space
Hospitals – 250-400 gallons per day per bed
Swimming pools – 10 gallons per day per swimmer
Picnic grounds with bathhouses, showers, & flush toilets – 20 gallons per day per person
Restaurants with bar/lounge, toilet facilities – 9-12 gallons per day per patron
Schools (day) with cafeteria, gym and showers – 25 gallons per day per student
Schools (boarding) – 75-100 gallons per day per student
Churches – 5 gallons per day per person
Service Stations – 10 gallons per day per vehicle
Stores – 400 gallons per day per restroom
Airports – 3-5 gallons per day per passenger
Irrigation – A total diversion of 0.02 cfs per acre irrigated, unless the applicant or claimant can demonstrate that more is required. For irrigated tracts of 5 acres or less, no additional justification is required for up to 0.03 cfs per acre. For irrigation of public spaces, such as parks and school grounds, IDWR will authorize a diversion rate of 0.02 cfs per acre times 24 divided by the number of hours irrigation actually occurs each day. For example, a park irrigated for 8 hours overnight could divert up to 0.06 cfs per acre.
