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Changed Water Right Plan Structure

A Plan Type 13 – Changed Water Right Plan structure is used to temporarily divert and store a water right that has been changed for uses other than its historical use. This commonly occurs when water users purchase a portion of a senior water right historically used for irrigation, change the use in Water Court, and then use the changed water rights for other uses such as municipal, industrial, or augmentation. If the changed water right is to be divided among more than one user, as shown in the example schematic above, then an overall plan is needed to store the total changed portion, and individual plans are needed for each user for a total of three plans. If more than one water right is changed at the same source location, they can be put into the same overall plan only if all the water rights can be split to individual user plans using the same percentages and if the terms and conditions applied when the plans release the water to the end uses are the same.

As the changed water right plan operations are all accounted for at the source water right headgate (administrative) location, all the plans must be modeled off-channel on a “mock” tributary so they do not affect exchange potential or other operations on the mainstem. Note that the changed water rights are only available for use in the same time step they are diverted and must be “spilled” back to the river if they are not used.

The user should keep in mind that the changed water rights plan “demand” is the portion of the water that is changed; regardless if there is a final demand for the changed water when the water is released. For example, if 100 cfs is available under the full water right, and 50 percent of the ditch has been changed, then 50 cfs will be stored in the plan structure and the remaining 50 cfs will go towards meeting the headgate demand. Even if the 50 cfs that was stored in the plan is not used and is ultimately spilled back to the river, and the headgate demand is unmet, the spilled water will not go to meet the headgate demand. If the changed water can be used to meet the headgate demand, it is recommended the user set up a separate operating rule to release from the changed water rights plan to the headgate demand. Additionally, if there is no headgate demand, then all of the water right must be put into the plan.

The operating rule used to temporarily store water in the changed water rights plan (Type 26) does not limit the changed water by the capacity of the source water right location; this limitation is performed when the water is released from the plan. This ensures that capacity is not “used” with water that was only temporarily stored, and may not be ultimately used to meet demand. Similar logic can be applied to implementing Terms and Conditions associated with the historical use of the water, generally outlined in the change of use decree. The Terms and Conditions operations, which ultimately generate a plan demand, should be based only on the water that is actually released and used to meet a demand, not based on the water stored in the plan. Therefore it is recommended the user include Terms and Conditions in the plan release operations. See the following Releases from a Changed Water Right Plan section for more information on limiting the changed water right by the source diversion structure’s capacity and implementing Terms and Conditions.

  1. Open the network (*.net) in StateDMI, navigate to the source water right headgate, and right-click to Add an Upstream Location. Create a new tributary, enter the appropriate structure information, and designate the structure type as a plan.
    • If more than one changed water rights plan will be required to model the operations, as shown in the example schematic above, add the additional plan structures on the mock tributary in this step.
  2. Recreate the river network file (*.rin) to reflect the additional structure.
  3. In the plan file (*.pln), include the changed water right plan as a Type 13 Plan and include the appropriate parameter information. See Section 4 for more discussion on the information in and format of this file.
  4. In the operating rule (*.opr) file, include a Changed Water Right Operating Rule (Type 26) to divert each water right into a changed water right plan.
    • The source is the changed water right ID and the destination is the changed water right plan.
    • Set the priority to be the same as the priority of the source water right in the diversion rights (*.ddr) file.
    • Set the monthly and annual limitations; generally based on limits on the changed right by the decree.
    • Set the percent of the water right that is changed and therefore stored in the plan. If the portion of the water right to be stored in the plan is not 100 percent, the remaining amount is used to meet any demand at the source water right headgate. The Type 26 turns off the water right so it cannot be used in other operating rules.
    • The Type 26 operating rule operates only once per time step (i.e. does not re-operate).
  5. If more than one changed water right plan is necessary, in the operating rule (*.opr) file, include a Multiple Plan Ownership Operating Rule (Type 46) to split the overall changed water right plan (as referenced as the destination in the Type 26 rule) into multiple owner’s plans.
    • The split percentages to the individual users’ changed water rights plan must add up to 100 percent.
    • Set the priority to be just junior to the Type 26 operating rule.