StateMod uses plan structures to model complex operations, such a reusable supplies, recharge supply and augmentation demands, terms and conditions, changed water rights, out-of-priority plans, and imports. The specific operation desired by the user is defined by the type of plan structure used, the associated plan input files, and the array of operating rules required to operate the plan structure. See Section 7.8 for additional discussion on how to model plan structures and operations.
Eleven plan types are currently available; note that Plan Type 5 and Type 6 are intentionally omitted as they are no longer functional in StateMod:
- Type 1 - T&C Plan is used to store a future obligation associated with the transfer of water from one structure to another. For example, a water right transfer might require historical return flows be maintained as part of the transfer. When a T&C plan is specified, StateMod calculates the obligation for the time step it occurs and all associated future time steps. Future returns and/or depletions are estimated using the same delay information specified for the source structure or in the operating rule that includes the T&C plan.
- Type 2 - Well Augmentation Plan is used to store a future obligation to return water to the river (augment) when a well depletes the river out of priority. When a Well Augmentation Plan is specified, StateMod calculates the current and future obligation for the time step it occurs and all associated future time steps. Future returns and/or depletions are estimated using the same delay information specified for the source well structure.
- Type 3 - Reservoir Reuse Plan is used to store a reusable water supply associated with a reservoir. As the reuse plan represents water stored in the reservoir, any unused water can be carried over in the plan to the next time step.
- Type 4 - Non-Reservoir (Diversion) Reuse Plan is used to store a reusable water supply associated with a diversion. As the reuse plan is associated with a diversion, any unused water must be spilled since it cannot be carried over to the next month.
- Type 7 - Transmountain Import Plan is used to account for imported water which, in many cases, may be used to extinction. The return flows generated from deliveries from a Type 7 plan are typically stored in Type 3 or Type 4 Reuse Plans. See the “How to Model Imports” section (Section 7.13) for more information on this plan type and import operations.
- Type 8 - Recharge Plan is used to store a water supply that originated from reservoir, recharge area, or canal seepage. The water supply from this plan is typically used to meet a well augmentation demand generated in a Type 2 plan. The return to the river is controlled by a unit response table therefore it accrues to the river as a supply even if it is not assigned to a demand.
- Type 9 - Out of Priority Plan is used to store a future obligation associated with water that is diverted out of priority. These plans are typically used to represent out-of-priority diversions to storage pursuant to the upstream storage statute (e.g. Blue River decree diversions by Denver and Colorado Springs).
- Type 10 - Special Well Augmentation Plan is used to store the depletion associated with a well that is not required to be augmented. Examples include pumping in a designated basin or pumping by a well which has been decreed to be non-tributary (i.e. “coffin wells”). A special augmentation plan is typically used to demonstrate that every well in the model is assigned to an augmentation plan even if some wells are not required to augment their depletions.
- Type 11 - Accounting Plan is used to “temporarily” divert water in priority which may subsequently be used at a later point in the priority system or by a number of other structures. Note this plan type was historically used for changed water rights, however due to the complexity of those operations, Plan Type 13 was developed exclusively for those operations. The Type 11 plan is still used in special operations such as the South Platte Compact.
- Type 12 - Release Limit Plan is used to limit the cumulative supply from multiple sources to monthly and annual values. This plan is typically included in a series of other operating rules to limit the total amount of diversions or reservoir releases to a user-specified monthly or annual amount.
- Type 13 – Changed Water Rights Plan is a specific type of accounting plan that is used to handle changed water right operations, allowing water to be “temporarily diverted” in priority, split to other Type 13 plans if the changed right has more than one owner, then released at a later priority to meet demands.
The following are noted:
- Section 4.49 describes the physical data associated with a plan which includes its ID, name and location in the stream network.
- Water accounted for in various reuse plans be used as a source for many other operating rules.
- If a plan is not specified as a part of an operating rule or well water right, StateMod warns the user but assumes there are no terms and conditions to be imposed.
- Total demand and supply associate with a plan are reported as part of the standard stream node output (*.xdd) under the plan ID and appropriate location in the network.
- Detailed reporting of a plan is provided in a standard plan output file (*.xpl).
- Reservoir reuse plans are used to account for reusable water associated with an account in a reservoir. Reservoir reuse plans can be located anywhere in the network but are typically located adjacent to the associated reservoir. Reusable water supplies can be accounted for by assigning a reservoir reuse plan as part of an operating rule.
- Non-reservoir reuse plans are located on the stream network where the water is physically located.
- Terms and conditions (T&C) plans are located on the stream network at the most upstream location(s) where the terms and conditions of a water transfer are to be implemented (e.g. if a term and condition of a transfer requires a diversion leave historic return flows at the transfer location, then the plan should be located just downstream of the transfer location). Return flow obligations associated with a term and condition are a function of how much water gets transferred. Therefore when a terms and conditions (T&C) plan is specified, StateMod calculates the obligation on-the-fly for the month it occurs and all associated future months. Future return flow and/or depletion percentages and patterns may be specified to equal the same values as the source structure or the plan itself. The terms and conditions are defined within the operating rule.
- Well augmentation plans should be located on the stream network at the most upstream location(s) where the lagged pumping depletions affect the river. The lagged river depletions associated with operating a well water right out-of-priority represents the demands for a well augmentation plan. The timing pattern of depletions from pumping are included in the unit response table (monthly - *.urm; daily - *.urd). Lagged river depletions associated with well pumping are a function of how much pumped water is simulated. When a well augmentation plan is specified, StateMod calculates the lagged river depletion on-the-fly the month it occurs and all associated future months. Operating rules can be used to satisfy this demand when a well is in priority or from other water supplies, including accretions from recharge diversions (Recharge Plan).
- Accretions associated with recharge water rights diverted from the river to recharge sites can be represented in Recharge Plans. Recharge plans are located on the stream network at the location(s) where the lagged river accretions associated with recharge diversions have been separately estimated to occur. The timing pattern of accretions from recharge diversions is included in the unit response table (monthly - *.urm; daily - *.urd). Lagged river accretions associated with recharge diversions are a function of how much recharge diversion is simulated. When a recharge plan is specified, StateMod calculates the lagged river depletion on-the-fly the month it occurs and all associated future months. Operating rules can be used to supply the calculated accretions to meet other demands (e.g. well augmentation plan demands).
- Out-of-Priority plans are used to represent out-of-priority diversions to storage pursuant to the upstream storage statute (e.g. Blue River decree diversions by Denver and Colorado Springs). Accounting for replacement requirements associated with upstream storage statute operations are specified within the operating rule. Operating rules can be used to satisfy this demand when from other water supplies.
- Release limit plans are currently implemented for representing monthly and annual limits to reservoir releases (e.g. Green Mountain Reservoir HUP pool releases to Senate Document 80 beneficiaries).
- Special Well Augmentation Plans are used to represent lagged well depletions to the river system for wells that are considered not tributary to the river system (i.e. Coffin wells and designated basin wells). The timing pattern of depletions from pumping are included in the unit response table (monthly - .*urm; daily - *.urd). Lagged depletions associated with well pumping are a function of how much pumped water is simulated. When a special well augmentation plan is specified, StateMod calculates the lagged depletion on-the-fly the month it occurs and all associated future months.