Lateral Ditch Water Users Laws

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Calculating a Water User Rotation Schedule

A proper water user rotation schedule should be based on either the water right or the acreage of the different water users of any particular water tap. If the water right is chosen then you must make sure that all water rights allocated are equal in flow rate to each tract of land. If they are, then use the acreage to determine the proper time allotment for each tract of land. If they are not, then you must calculate each tract based on water right.

For this exercise, we shall figure allotted times based on acreage. This calculation should be done on an annual basis so as to update property ownership changes and to remind each and every water user about their share in the proper use of water.

1.            Obtain an updated lateral and tap report from the irrigation district.

2.            Go to the last page and obtain the totals of all acres for your water delivery. This may include one or all of the following: Ridenbaugh, Project, or other District acreages. (see example sheet)

3.            Your water user association should decide how many days should be used in the rotation of the water -what is best for the majority of the group. For this exercise, we shall use a 7 day rotation.

4.            In this example, there is a total of 32.75 Project acres. In 7 days (7 days x 24 hours x 60 minutes) there are 10080 minutes. The 10080 minutes are then divided amongst the 32.75 acres. (308 minutes per acre)

5.            Now you’re ready to calculate each tract of land separately. 1.9 acres x 308 (minutes per acre) = 585 minutes or 9 hours 45 minutes for this tract of land. Follow this same pattern through the rest of the water users. Always round up the partial minute to an additional minute when it is above .50 or round down if it’s under .50. The schedule must come out to a total equal to 168 hours (7×24). It’s a good idea to add the total times to check your figures.

6.            The best way to assign times to your water users is to start at the head of the ditch and work your way down. That way, when it becomes your turn, the water is right next door. When the water user rotation schedule is followed closely, the water users are much more content. It leaves no room for argument. If someone chooses not to use the water for the season, the water master should be notified so that he may adjust the water season schedule accordingly.

How to Make a Water Schedule on a 7-Day Rotation

7 days x 24 hours= 168.0

Take total of miner inches for all water users and divide by total of hours (168.0)

Take the total number of hours of this figure and x by each individual water users miner inches.


7 X 24 = 168

36.21 total miner inches divided by 168 equals 22 hrs per miners inch

1.81 individual miners inches x 22 equals 39.82 hours

2.95 individual miner inches x 22 equals 64.90 hours