Augmentation or Recharge Well Pumping as an Augmentation Supply

StateMod has the ability to pump either a recharge or augmentation well to meet an outstanding augmentation requirement. Due to the pumping costs associate with this supply and the fact that the pumping itself can result in an increased augmentation demand, these supplies are generally used only when other supplies are not available. These wells are generally not exclusively used for augmentation and/or recharge, but also pump to meet irrigation demands.

An augmentation well is generally located farther away from the river (i.e. its depletions generally have a longer depletion pattern) but its pumped water is conveyed directly to the river to offset an augmentation requirement. The augmentation well depletions are generally covered by the same augmentation plan (as tied in the well augmentation plan data (*.plw) file) that the pumping is used to offset, however the future depletions are traded for immediate augmentation supply.

A recharge well is generally located closer to the river (i.e. a short depletion pattern) and pumps water to a recharge area with a longer depletion pattern where it seeps back to the river to offset a future augmentation requirement. StateMod only allows the recharge well to pump when it’s in priority, therefore it does not create an augmentation requirement.

Both types of wells can be modeled in StateMod either as explicit well structures or as a group of wells aggregated under a single well structure. As augmentation plans can add or remove augmentation and recharge wells from their plans, the aggregate well structure approach is discussed herein. This approach allows a single file and operating rule to be changed as wells are added or removed, and limits the need to update the network and all well input files.

1. Open the network (*.net) in StateDMI, navigate to the appropriate location, and right-click to Add an Upstream Location. Enter the appropriate location and structure information and designate the structure type as a well structure.
   • It is recommended the well structure ID reflect the augmentation plan ID the wells will supply and a suffix indicating the type of wells they are (e.g. _ReW or _AuW).
2. Recreate the river network file (*.rin) to reflect the additional structure.
3. Add the well structure to the well station (*.wes) file using the StateDMI commands:
   • Set the total well capacity in CFS.
   • Set the well system efficiency as 0 percent (100 percent returns to either the recharge area or to a river location).
   • Set the demand and use types (see Section 4 for more discussion).
   • Set the depletion and return flow locations and patterns; must reference the delay patterns provided in the delay file (*.dly or *.urm).
     • Recharge wells generally deplete the river in the same time step and pump to the recharge area in the same time step.
     • Augmentation wells generally deplete the river with a lagged pattern and pump to the river in the same time step.
4. Add the well structure to well right (*.wer) file using the StateDMI commands:
   • Use HydroBase to pull well rights for each well or set each well water right; in both situations, tie each water right to the ground water only structure ID.
   • Set the water right priority (administration number) and amount in CFS.
   • Review options to determine if a “turn-on” date is appropriate; note that a “turn-off” date has not been implemented and once a well is turned on, it is available to pump for the remainder of the model period.
5. Add the well structure with a zero demand to the well demand file (*.wem) using the TSTool commands. Well pumping will occur based on the augmentation requirement of the augmentation plan.
6. In the operating rule (*.opr) file, include an Augmentation Well (Type 44) operating rule associating the augmentation well structure to the augmentation plan.
   • The source is the well right ID and the destination is the augmentation plan.
   • The operating rule generally reflects a junior priority relative to other augmentation supplies.
   • If appropriate, include the augmentation plan in the operating rule in which the augmentation well depletions will be stored.
7. In the operating rule (*.opr) file, include a Recharge Well (Type 37) operating rule associating the recharge well structure to the recharge area.
   • The source is the well right ID and the destination is the recharge area.
   • The operating rule must reflect the priority of the well right used for the recharge operations.
8. Review the plan summary (*.xpl) file for information on the portion of the augmentation requirement that was offset by the recharge or augmentation well supply and the well summary (*.xwe) file for output information on the well structures.