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Water User
Objects and Methods
Water User
The Water User object can exist as a separate Stand Alone object on the workspace as well as a member element of the Aggregate Diversion Site (Agg Diversion Site) object. The Water User simulates the consumption/depletion of water often from a reservoir or reach.
When the Water User object is an element of an Agg Diversion Site, the Link Structure selected on the Agg Diversion Site determines how the Water User elements interact with each other, the Agg Diversion Site, and the object from which water is being diverted (i.e. reach or reservoir). When the Water User is used as a single object on the workspace, it functions identically to an element on an Agg Diversion Site using the default (No Structure) linking structure. The three linking structures exist on the Agg Diversion Site object.
The general slots which exist on the Water User regardless of the type of linking structure that exists on the Agg Diversion Site are:
General Slots
Depletion Requested
Type: Series Slot
Units: Flow
Description: amount of water to be consumed, given the request is met
Information: Automatically linked to the Total Depletion Requested multislot on the Agg Diversion Site.
I/O: Input, Output, or set by a rule
Diversion Requested
Type: Series Slot
Units: Flow
Description: amount of water requested by the Water User
Information: Automatically linked to the Total Diversion Requested multislot on the Agg Diversion Site.
I/O: Input, Output, or set by a rule
Water User Groups
Type: List Slot
Units: NA
Description: Contains the user-defined subbasins to which this Water User is a member. It can be used to encode and display attributes of the Water User. For example, a water user may only be able to use Imported Water while other water users may only use Basin Water. By defining a subbasin for Imported Water and one for Basin Water and adding the appropriate water users to each, you can keep summarize information about each group of users. Perhaps you wish to create an expression slot that sums up the total diversion requested for Imported Water. You can use the Imported Water subbasin. The Water User Groups slot then allows you to see, from each water user, the groups to which it belongs.
Information: This slot is a special type of list slot called Subbasin Membership List Slot. The values in the slot are the subbasins to which this water user is a member. To add/remove an entry from the slot, you must go to the subbasin manager and add/remove the water user from the particular subbasin. The slot does provide a menu option to open the subbasin manager File->Edit Subbasins.
I/O: Specified by subbasin membership.
Stand-alone or No Structure Slots
In addition to the general slots above, the following slots are shown for a stand alone water user or when the parent Agg Diversion Site has the No Structure selected.
Note:  The No Structure method is the default linking structure.
Depletion
Type: Series Slot
Units: Flow
Description: amount of water consumed by the water user
Information:  
I/O: Output only
Depletion Shortage
Type: Series Slot
Units: Flow
Description: the difference between the Depletion Requested and the Depletion
Information: This value is only calculated if Depletion Requested and Depletion are both valid.
I/O: Output only
Diversion
Type: Series Slot
Units: Flow
Description: amount of water actually taken (diverted) by the water user
Information:  
I/O: Optional; Can be input or calculated based on Diversion Requested and Incoming Available Water (see dispatch methods).
Diversion Shortage
Type: Series Slot
Units: Flow
Description: the difference between the Diversion Requested and the Diversion
Information:  
I/O: Output only
Incoming Available Water
Type: Series Slot
Units: Flow
Description: water available to be diverted
Information: It is the user’s responsibility to link this slot to the appropriate slot on the object from which water is diverted if using No Structure.
I/O: Set via link
Lumped Structure Slots
In addition to the general slots above, the following slots are shown when the parent Agg Diversion Site has the Lumped Structure selected.
Depletion Shortage
Type: Series Slot
Units: Flow
Description: The amount of the Depletion Request that could not be met.
Information: This value is calculated by the Agg Diversion Site when it dispatched. Depletion Requested must be valid. See “Process Lumped given Diversion Requested” for details.
I/O: Output only
Description: Usually not linked
Sequential Structure Slots
In addition to the general slots above, the following slots are shown when the parent Agg Diversion Site has the Sequential structure selected.
Outgoing Available Water
Type: Series Slot
Units: Flow
Description: portion of the Incoming Available Water that is unused by the Water User
Information:  
I/O: Output only
When the sequential linking structure is active, the Incoming Available Water slot on the first Water User element is automatically linked to the Total Diversion slot on the Agg Diversion Site.
User Methods
The user methods categories available on the Water User object are dependent upon the linking structure selected on the Agg Diversion Site object. The Water User object only dispatches when either the No Structure or Sequential Structure linking structures are selected on the AggDiversion Site. Therefore, return flow categories are only available when one of these two linking structures are selected. If Lumped Structure is selected, the Water User object simply contains the values of Depletion Requested and Diversion Requested that are used by the Agg Diversion Site. These values can be calculated by the Water User based on agricultural data.
When the Water User is not used as an element in the Agg Diversion Site, it has the same user methods as an element in the No Structure linking structure.
Diversion and Depletion Request
This user method category is common to all three linking structures. The methods available in this category are used to calculate the Water User’s Diversion Requested and Depletion Requested. These slots are either set by user input or calculated based on the methods described below.
Note:  These methods are executed at different times depending on the method, as follows:
• Reservoir Level Lookup is executed at the beginning of the timestep.
• Irrigation Requests with Soil Moisture is executed partially at the beginning of the timestep and partially in the dispatch method.
• All other methods are executed at beginning of run. As a result, any input data will be used in the calculations as described. If you plan to use a rule to set either Diversion Requested or Depletion Requested, the other one will not be calculated using these methods as it will not be known at the beginning of the run. In this situation, the rule must set Diversion Requested to allow the water user to dispatch and solve. Depletion Requested, if not specified, will be set equal to Diversion Requested for internal calculations but will not be set on the slot.
* Input Requests
This method is common for all linking structures. It is used when the user wants to manually set the values of Diversion Requested and/or Depletion Requested. This is the default method for the Diversion and Depletion Request category.
Slots Specific to This Method
Minimum Diversion Request
Type: Table Slot
Units: Flow
Description: minimum possible flow rate needed to meet depletion requests
Information: The Minimum Diversion Request can be based on either physical, legal, or environmental restrictions, etc. This is only used if the Depletion Request is non-zero.
I/O: Optional.
No calculations are performed with this method. The user can specify either Diversion Request or Depletion Requested or both. If only Diversion Requested is known, Depletion Requested is set equal to Diversion Requested. If only Depletion Requested is known, Diversion Requested is set equal to Depletion Requested. If Depletion Requested and Minimum Diversion Request are known and Diversion Requested is not, Diversion Requested is set equal to the maximum of Depletion Requested and Minimum Diversion Requested.
See the note in “Diversion and Depletion Request” for details on how this method behaves in Rulebased Simulation.
* Input Diversion Requests
The Input Diversion Requests method computes Depletion Requested based on an input Diversion Requested.
Slots Specific to This Method
Minimum Efficiency
Type: Series Slot
Units: Fraction
Description: minimum amount of consumed flow per unit diverted flow
Information: Expressed as a fraction
I/O: Required input
When Diversion Requested is input, Depletion Requested is computed as follows:
See the note in “Diversion and Depletion Request” for information on how this method behaves in Rulebased Simulation.
* Input Depletion Requests
The Input Depletion Requests method computes Diversion Requested based on an input Depletion Requested.
Slots Specific to This Method
Minimum Efficiency
Type: Series Slot
Units: Fraction
Description: minimum amount of consumed flow per unit diverted flow
Information: Expressed as a fraction
I/O: Required input
Maximum Flow Capacity
Type: Table Slot
Units: Flow
Description: maximum possible flow rate through the distribution system
Information: The Maximum Flow Capacity can be based on either physical, legal, or environmental restrictions, etc.
I/O: Required input
When Depletion Requested is input, Diversion Requested is computed as follows:
See the note in “Diversion and Depletion Request” for information on how this method behaves in Rulebased Simulation.
* Irrigation Requests
This user method uses irrigation data to determine Depletion Requested and/or Diversion Requested if they are not input. Depletion Requested is based on the area to be irrigated, evapotranspiration rate, and incidental rate loss. Diversion Requested is then calculated from the Depletion Requested and the Minimum Efficiency.
Slots Specific to This Method
Evapotranspiration Rate
Type: Series Slot
Units: Length Vs Time
Description: rate of water loss due to evaporation and transpiration
Information:  
I/O: Optional; required if Depletion Requested is not input.
Incidental Loss Rate
Type: Table Slot
Units: Fraction
Description: losses in the water distribution system
Information: Expressed as a fraction of the flow.
I/O: Optional; required if Depletion Requested is not input.
Irrigated Area
Type: Series Slot
Units: Area
Description: surface area of the land to be irrigated
Information:  
I/O: Optional; required if Depletion Requested is not input.
Maximum Efficiency
Type: Table Slot
Units: Fraction
Description: maximum amount of consumed flow per unit diverted flow
Information: Expressed as a fraction.
I/O: Required input
Maximum Flow Capacity
Type: Table Slot
Units: Flow
Description: maximum possible flow rate through the distribution system
Information: The Maximum Flow Capacity can be based on either physical, legal, or environmental restrictions, etc.
I/O: Required input
Minimum Diversion Request
Type: Table Slot
Units: Flow
Description: minimum possible flow rate needed to meet depletion requests
Information: The Minimum Diversion Request can be based on either physical, legal, or environmental restrictions, etc. This is only used if the Depletion Request is non-zero.
I/O: Optional.
Minimum Efficiency
Type: Series Slot
Units: Fraction
Description: minimum amount of consumed flow per unit diverted flow
Information: Expressed as a fraction.
I/O: Required input
If not input, the Depletion Requested is calculated as follows:
Then, Diversion Requested (if it is not specified by the user) is calculated as follows:
After the Diversion Requested and Depletion Requested are initially calculated, Diversion Requested must be checked against the Maximum Flow Capacity. If the calculated value for Diversion Requested is less than the Maximum Flow Capacity, the Diversion Requested slot is set to the calculated value. If the calculated Diversion Requested is greater than the Max Flow Capacity, it is set to the Maximum Flow Capacity.
Note:  User input overrides all calculated values. If the user specifies a Diversion Requested which is greater than the Maximum Flow Capacity, an error is posted and the run aborts.
Diversion Requested must also be checked against the Minimum Diversion Request (if specified by user) If the calculated value for Diversion Requested is greater than the Minimum Diversion Request, the Diversion Requested slot is set to the calculated value. If the calculated Diversion Requested is less than the Minimum Diversion Request, it is set to the Minimum Diversion Request.
Note:  User input overrides all calculated values. If the user specifies a Diversion Requested which is less than the Minimum Diversion Request (if specified), an error is posted and the run aborts.
The Depletion Requested divided by the Diversion Requested (i. e. the Water User’s efficiency) is compared to the Maximum Efficiency allowed on the Water User. If the calculated value is less than the Maximum Efficiency, Depletion Requested is unchanged. If the calculated efficiency (Depletion Requested/Diversion requested) is greater than the Maximum Efficiency (and Depletion Requested is not input by the user), Depletion Requested is reset to the value of Diversion Requested multiplied by the Maximum Efficiency. If the calculated efficiency is greater than the Maximum Efficiency and Depletion Requested is input, an error is posted and the run aborts.
See the note in “Diversion and Depletion Request” for information on how this method behaves in Rulebased Simulation.
* Irrigation Requests with Soil Moisture
This method uses irrigation data to determine Diversion and Depletion Requests based on the irrigated acreage, evapotranspiration rate, and soil moisture. The Soil Moisture Demand and available soil moisture is also computed. This method is available for all Agg Diversion Site linking structure and for stand alone water users.
Note:  You must also select the Proportional Shortage with Soil Moisture, Proportional Shortage with Soil Moisture, or Variable Efficiency with Soil Moisture method. See “Variable Efficiency with Soil Moisture” for details.
In addition, when this method is selected, the following dispatch methods are available based on the link structure:
• Stand alone Water User or Water User in a No Structure Agg Diversion Site:
– Solve Stand alone given Depletion Requested
– Solve Stand alone given Diversion
– Water User in a Sequential Agg Diversion Site:
– Solve Sequential given Depletion Requested
– Solve Sequential given Diversion
• Water User in a Lumped Agg Diversion Site: This method cannot be selected. The Water user doesn’t dispatch in a Lumped Agg Diversion Site.
Figure 28.1 is a conceptual diagram of all of the components possible to model Soil Moisture on the Water User.
• Items in blue are default flow values.
• Pink indicates optional gains/losses.
• Green is supplemental water. See “Supplement Diversion including Soil Moisture” for details on supplemental flow.
• Brown indicates how the return flows can be split and/or routed.
Note:  Not all values shown are separate slot values.
Figure 28.1   
Slots Specific to This Method
Evapotranspiration Rate
Type: Series Slot
Units: Length Vs Time
Description: rate of water loss due to evaporation and transpiration
Information:  
I/O: Specified according to the selected method in the Irrigation Acreage and Evapotranspiration Rates category. See “Irrigation Acreage and Evapotranspiration Rates”.
Incidental Loss Rate
Type: Table Slot
Units: Fraction
Description: losses in the water distribution system.
Information: Expressed as a fraction of the flow.
I/O: Optional; if not specified, zero is assumed.
Irrigated Area
Type: Series Slot
Units: Area
Description: surface area of the land to be irrigated
Information:  
I/O: Specified according to the selected method in the Irrigation Acreage and Evapotranspiration Rates category. See “Irrigation Acreage and Evapotranspiration Rates”.
Maximum Flow Capacity
Type: Table Slot
Units: Flow
Description: maximum possible flow rate through the distribution system
Information: The Maximum Flow Capacity can be based on either physical, legal, or environmental restrictions, etc.
I/O: Required input
Minimum Diversion Request
Type: Table Slot
Units: Flow
Description: minimum possible flow rate needed to meet depletion requests
Information: The Minimum Diversion Request can be based on either physical, legal, or environmental restrictions, etc. This is only used if the Depletion Request is non-zero.
I/O: Optional.
Minimum Efficiency
Type: Series Slot
Units: Fraction
Description: minimum amount of consumed flow per unit diverted flow
Information: Expressed as a fraction.
I/O: Required input
Diversion Request for Soil Moisture
Type: Series Slot
Units: Flow
Description: The requested diversion explicitly to refill the soil moisture.
Information:  
I/O: Output only
Diversion Request for Crops
Type: Series Slot
Units: Flow
Description: The requested diversion to meet crop depletion
Information:  
I/O: Output only
Soil Moisture Future Timesteps
Type: Scalar
Units: No Units
Description: The number of timesteps past the current timestep for the calculations should be performed
Information: This must be an integer greater than 0.
I/O: If not specified, the value will be set to 1, which indicates that only the current timestep will be computed
Maximum Soil Moisture
Type: Scalar
Units: Length
Description: The effective depth of water that the soil can hold. Conceptually it is the actual depth multiplied by the effective porosity.
Information:  
I/O: Required Input
Maximum Infiltration Rate
Type: Scalar
Units: Velocity (Length per Time)
Description: Maximum depth of water per time (i.e an absorption rate) that can be absorbed by the soil
Information: A valid value must be specified or an error will occur at the beginning of run.
I/O: Required Input
Soil Moisture
Type: Series Slot
Units: Volume
Description: This slot tracks the volume of soil moisture water in the soil at each timestep in the run.
Information: For the initial timestep, this slot must be valid. If this slot is not input, it will be computed as the Maximum Soil Moisture times the Irrigated Area at the initial timestep. That is, the soil moisture starts full.
I/O: Typically Output for run timesteps.
Soil Moisture Demand Factor
Type: Series Slot with Periodic Input
Units: Fraction
Description: This slot is used to limit the soil moisture demand
Information:  
I/O: Optional input as either a series or a periodic relationship. If not specified, it is assumed to be 1.
Soil Moisture Fill Efficiency
Type: Series Slot with Periodic Input
Units: Fraction
Description: The fraction of the flow applied for soil moisture refill that is not absorbed.
Information: For example, if you are only refilling the soil moisture, you may apply 100 cfs, but 5 cfs is not absorbed even though max infiltration indicated it could absorb 200cfs. The Soil Moisture Fill Efficiency would be 0.95.
I/O: Optional input, if not input, it is assumed to be 1.0.
Soil Moisture Demand
Type: Series Slot
Units: Flow
Description: The flow necessary to refill the soil moisture to capacity.
Information:  
I/O: Output only
Soil Moisture Stress Coefficient
Type: Series Slot
Units: Fraction
Description: This coefficient represents a stress term that can be used to reduce the depletion request when in shortage.
Information:  
I/O: Optional input or set by a rule. If not specified, the value is assumed to be 1.0, but no value is set on the slot. Since this method is executed at the beginning of the timestep, if you wish to set this slot with a rule, the rule must set it at the previous timestep.
Soil Moisture Gain Loss
Type: Series Slot
Units: Volume
Description: Miscellaneous gain or loss of soil moisture volume during the timestep.
Information: This slot represents and gains (positive) or loss (negative) from the soil moisture. It is used to track the soil moisture volume lost when the irrigated acreage is reduced from the previous timestep. In this case it is a computed output. If the irrigated acreage increases, you may wish to have the new acreage start with some soil moisture (perhaps due to precipitation). In this case, you can input a positive volume that will be added to the Soil Moisture.
I/O: Typically Output but can be Input
Method Details
The Irrigation Requests with Soil Moisture method is executed in two parts, the first occurs at the beginning of each controller timestep and then the rest is executed from the dispatch method.
Beginning of Timestep
Compute the Depletion Requested for all timesteps from the current timestep through the number of Soil Moisture Future Timesteps. This represents the crop demand for each of these timesteps.
At the start of the dispatch method
Recompute the Depletion Requested if any of the pieces have changed (by a rule).
Compute the maximum infiltration flow intermediate variable, as follows:
Compute the Soil Moisture Gain Loss (if not input or set by a rule)
If the current Irrigated Area is less than the Irrigated Area(t-1), compute as follows:
This loss will keep the new irrigated area at its same relatively fullness (at the start of the timestep), the lost water only comes from the area no longer irrigated.
Note:  Soil Moisture Gain Loss can also be input and will be used in the following equation.
Compute the flow necessary to refill the soil moisture back to the maximum (intermediate), as follows:
Compute the soil moisture demand, representing the physical constraints on refilling the soil moisture from diverted surface water, as follows:
The Depletion Requested (crop demand) is subtracted from the maxInfiltrationFlow as all water applied to the fields must adhere to the max infiltration rate.
Compute the Diversion Request for Soil Moisture as follows:
Compute the Diversion Request for Crops as follows:
Compute the total Diversion Requested (if not input or set by a rule) as follows:
After the Diversion Requested and Depletion Requested are initially calculated, Diversion Requested is checked against the Maximum Flow Capacity. If the calculated value for Diversion Requested is less than the Maximum Flow Capacity, the Diversion Requested slot is set to the calculated value. If the calculated Diversion Requested is greater than the Max Flow Capacity, it is set to the Maximum Flow Capacity.
Note:  User input overrides all calculated values. If the user specifies a Diversion Requested which is greater than the Maximum Flow Capacity, an error is posted and the run aborts.
Diversion Requested must also be checked against the Minimum Diversion Request (if specified by user) If the calculated value for Diversion Requested is greater than the Minimum Diversion Request, the Diversion Requested slot is set to the calculated value. If the calculated Diversion Requested is less than the Minimum Diversion Request, it is set to the Minimum Diversion Request.
Note:  User input overrides all calculated values. If the user specifies a Diversion Requested which is less than the Minimum Diversion Request (if specified), an error is posted and the run aborts.
* Head Gate Sprinkler Requests
Caution:  This method is specific to the San Juan Basin and may not be physically valid in other situations. Take care when using this method.
The Head Gate Sprinkler Requests method uses agricultural data along with data on sprinkler evaporation to determine Depletion Requested and Diversion Requested. The method is very similar to the Irrigation Requests method except that a sprinkler evaporation rate is included in calculating Depletion Requested.
Slots Specific to This Method
Evapotranspiration Rate
Type: Series Slot
Units: LENGTH/TIME
Description: rate of water loss due to evaporation and transpiration
Information:  
I/O: Optional; required if Depletion Requested is not input.
Incidental Loss Rate
Type: Table Slot
Units: Fraction
Description: losses in the water distribution system
Information: Expressed as a fraction of the flow.
I/O: Optional; required if Depletion Requested is not input.
Irrigated Area
Type: Series Slot
Units: Area
Description: surface area of the land to be irrigated
Information:  
I/O: Optional; required if Depletion Requested is not input.
Maximum Efficiency
Type: Table Slot
Units: Fraction
Description: maximum amount of consumed flow per unit diverted flow
Information: Expressed as a fraction.
I/O: Required input
Maximum Flow Capacity
Type: Table Slot
Units: Flow
Description: maximum possible flow rate through the distribution system
Information: The Maximum Capacity can be based on either physical, legal, or environmental, restrictions, etc.
I/O: Required input
Minimum Diversion Request
Type: Table Slot
Units: Flow
Description: minimum possible flow rate required to meet depletion requests
Information: The Minimum Diversion Request can be based on either physical, legal, or environmental restrictions, etc. This is only used if the Depletion Request is non-zero.
I/O: Optional.
Minimum Efficiency
Type: Series Slot
Units: Fraction
Description: minimum amount of consumed flow per unit diverted flow
Information:  
I/O: Required input
Sprinkler Evaporation Rate
Type: Table Slot
Units: Fraction
Description: evaporative losses in the sprinkler mechanism
Information: Expressed as a fraction of the diversion.
I/O: Required input
Initially, the Depletion Requested is calculated as follows (if it is not input):
Then, Diversion Requested (if it is not specified by the user) is calculated as follows:
After the Diversion Requested and Depletion Requested are initially calculated, the Diversion Requested must be checked against the Maximum Flow Capacity. If the calculated Diversion Requested is greater than the Max Flow Capacity, it is set to the Maximum Flow Capacity. If the calculated value for Diversion Requested is less than the Maximum Flow Capacity, the Diversion Requested slot is set with the calculated value.
Note:  User input overrides all calculated values. If the user specifies a Diversion Requested which is greater than the Maximum Flow Capacity, an error is be posted and the run aborts.
Diversion Requested must also be checked against the Minimum Diversion Request (if specified by user) If the calculated value for Diversion Requested is greater than the Minimum Diversion Request, the Diversion Requested slot is set to the calculated value. If the calculated Diversion Requested is less than the Minimum Diversion Request, it is set to the Minimum Diversion Request.
Note:  User input overrides all calculated values. If the user specifies a Diversion Requested which is less than the Minimum Diversion Request (if specified), an error is posted and the run aborts.
The sprinkler evaporation is applied to the Depletion Requested after the Diversion Requested slot has been set. The initial Depletion Requested is adjusted as follows:
The Depletion Requested divided by the Diversion Requested (i.e. the Water User’s Efficiency) is compared to the Maximum Efficiency allowed on the water User. If the calculated Water User’s efficiency is less than the Maximum Efficiency, the Depletion Requested Slot is set equal to the calculated value for Depletion Requested. If the calculated efficiency of the water user (Depletion Requested/Diversion requested) is greater than the Maximum Efficiency (and Depletion Requested is not input by the user), Depletion Requested is set to the product of the Diversion Requested and the Maximum Efficiency. If the calculated efficiency is greater than the Maximum Efficiency and Depletion Requested is input by the user, an error is posted and the run aborts.
See the note in “Diversion and Depletion Request” for information on how this method behaves in Rulebased Simulation.
* Population Requests
This user method uses population data to determine Depletion Requested and Diversion Requested if they are not input. Depletion Requested is based on the water user population, water use per individual, and incidental rate loss. Diversion Requested is then calculated from the Depletion Requested and the Minimum Efficiency.
Slots Specific to This Method
Use Rate Per Individual
Type: Series Slot
Units: Flow
Description: water use as flow per individual
Information:  
I/O: Optional; required if Depletion Requested is not input.
Incidental Loss Rate
Type: Table Slot
Units: Fraction
Description: losses in the water distribution system
Information: Expressed as a fraction of the flow.
I/O: Optional; required if Depletion Requested is not input.
Population
Type: Series Slot
Units: NoUnits
Description: the number of individuals in the water user population
Information:  
I/O: Optional; required if Depletion Requested is not input.
Maximum Efficiency
Type: Table Slot
Units: Fraction
Description: maximum amount of consumed flow per unit diverted flow
Information: Expressed as a fraction.
I/O: Required input
Maximum Flow Capacity
Type: Table Slot
Units: Flow
Description: maximum possible flow rate through the distribution system
Information: The Maximum Flow Capacity can be based on either physical, legal, or environmental restrictions, etc.
I/O: Required input
Minimum Diversion Request
Type: Table Slot
Units: Flow
Description: minimum possible flow rate required to meet depletion requests
Information: The Minimum Diversion Request can be based on either physical, legal, or environmental restrictions, etc. This is only used if the Depletion Request is non-zero.
I/O: Optional.
Minimum Efficiency
Type: Series Slot
Units: Fraction
Description: minimum amount of consumed flow per unit diverted flow
Information: Expressed as a fraction.
I/O: Required input
If not input, the Depletion Requested is calculated as follows:
Then, Diversion Requested (if it is not specified by the user) is calculated as follows:
After the Diversion Requested and Depletion Requested are initially calculated, Diversion Requested must be checked against the Maximum Flow Capacity. If the calculated value for Diversion Requested is less than the Maximum Flow Capacity, the Diversion Requested slot is set to the calculated value. If the calculated Diversion Requested is greater than the Max Flow Capacity, it is set to the Maximum Flow Capacity.
Note:  User input overrides all calculated values. If the user specifies a Diversion Requested which is greater than the Maximum Flow Capacity, an error is posted and the run aborts.
Diversion Requested must also be checked against the Minimum Diversion Request (if specified by user) If the calculated value for Diversion Requested is greater than the Minimum Diversion Request, the Diversion Requested slot is set to the calculated value. If the calculated Diversion Requested is less than the Minimum Diversion Request, it is set to the Minimum Diversion Request.
Note:  User input overrides all calculated values. If the user specifies a Diversion Requested which is less than the Minimum Diversion Request (if specified), an error is posted and the run aborts.
The Depletion Requested divided by the Diversion Requested (i. e. the Water User’s efficiency) is compared to the Maximum Efficiency allowed on the Water User. If the calculated value is less than the Maximum Efficiency, Depletion Requested is unchanged. If the calculated efficiency (Depletion Requested/Diversion requested) is greater than the Maximum Efficiency (and Depletion Requested is not input by the user), Depletion Requested is reset to the value of Diversion Requested multiplied by the Maximum Efficiency. If the calculated efficiency is greater than the Maximum Efficiency and Depletion Requested is input, an error is posted and the run aborts.
See the note in “Diversion and Depletion Request” for information on how this method behaves in Rulebased Simulation.
* Regional Requests
This user method uses regional data to determine Depletion Requested and Diversion Requested if they are not input. Depletion Requested is based on the regional water use, the fraction of the region that the water user represents, and incidental rate loss. Diversion Requested is then calculated from the Depletion Requested and the Minimum Efficiency.
Slots Specific to This Method
Regional Use Rate
Type: Series Slot
Units: Flow
Description: water loss due to regional use
Information:  
I/O: Optional; required if Depletion Requested is not input.
Incidental Loss Rate
Type: Table Slot
Units: Fraction
Description: losses in the water distribution system
Information: Expressed as a fraction of the flow.
I/O: Optional; required if Depletion Requested is not input.
Fraction of Region
Type: Series Slot
Units: FRaction
Description: fraction of the region using water at the regional rate
Information:  
I/O: Optional; required if Depletion Requested is not input.
Maximum Efficiency
Type: Table Slot
Units: Fraction
Description: maximum amount of consumed flow per unit diverted flow
Information: Expressed as a fraction.
I/O: Required input
Maximum Flow Capacity
Type: Table Slot
Units: Flow
Description: maximum possible flow rate through the distribution system
Information: The Maximum Flow Capacity can be based on either physical, legal, or environmental restrictions, etc.
I/O: Required input
Minimum Diversion Request
Type: Table Slot
Units: Flow
Description: minimum possible flow rate required to meet depletion requests
Information: The Minimum Diversion Request can be based on either physical, legal, or environmental restrictions, etc. This is only used if the Depletion Request is non-zero.
I/O: Optional.
Minimum Efficiency
Type: Series Slot
Units: Fraction
Description: minimum amount of consumed flow per unit diverted flow
Information: Expressed as a fraction.
I/O: Required input
If not input, the Depletion Requested is calculated as follows:
Then, Diversion Requested (if it is not specified by the user) is calculated as follows:
After the Diversion Requested and Depletion Requested are initially calculated, Diversion Requested must be checked against the Maximum Flow Capacity. If the calculated value for Diversion Requested is less than the Maximum Flow Capacity, the Diversion Requested slot is set to the calculated value. If the calculated Diversion Requested is greater than the Max Flow Capacity, it is set to the Maximum Flow Capacity.
Note:  User input overrides all calculated values. If the user specifies a Diversion Requested which is greater than the Maximum Flow Capacity, an error is posted and the run aborts.
Diversion Requested must also be checked against the Minimum Diversion Request (if specified by user) If the calculated value for Diversion Requested is greater than the Minimum Diversion Request, the Diversion Requested slot is set to the calculated value. If the calculated Diversion Requested is less than the Minimum Diversion Request, it is set to the Minimum Diversion Request.
Note:  User input overrides all calculated values. If the user specifies a Diversion Requested which is less than the Minimum Diversion Request (if specified), an error is posted and the run aborts.
The Depletion Requested divided by the Diversion Requested (i. e. the Water User’s efficiency) is compared to the Maximum Efficiency allowed on the Water User. If the calculated value is less than the Maximum Efficiency, Depletion Requested is unchanged. If the calculated efficiency (Depletion Requested/Diversion requested) is greater than the Maximum Efficiency (and Depletion Requested is not input by the user), Depletion Requested is reset to the value of Diversion Requested multiplied by the Maximum Efficiency. If the calculated efficiency is greater than the Maximum Efficiency and Depletion Requested is input, an error is posted and the run aborts.
See the note in “Diversion and Depletion Request” for information on how this method behaves in Rulebased Simulation.
* Periodic Diversion Request
This method is used to specify the Diversion Requested as a function of date/season using a periodic slot.
Slots Specific to This Method
Periodic Diversion Request
Type: Periodic Slot
Units: flow
Description: The diversion requested as a function of date/season
Information: The Diversion Requested is computed at the beginning of each timestep using the current date to look up the value from this slot.
I/O: Required input
The Periodic Diversion Request method executes at the beginning of the run. Each timestep is used to look up a value in the Periodic Diversion Request slot. The computed value is set in the Diversion Requested and Depletion Requested slots.
* Reservoir Level Lookup
The Reservoir Level Lookup method is used to compute the Diversion Requested as a function of the date/season and the operating level of a specified reservoir.
Slots Specific to This Method
Level vs Diversion Request
Type: Periodic Slot
Units: flow
Description: The diversion requested as a function of reservoir level and date/season
Information: Each column corresponds to a reservoir’s operating level. For each operating level, the diversion requested is specified for each date range in the periodic slot.
I/O: Required input
Diversion Request Reservoir
Type: List Slot
Units: None
Description: The reservoir used to compute the diversion requested
Information: The previous timestep operating level of this reservoir is used to look up the diversion requested in the Level vs Diversion Request slot.
I/O: Required input
Forecast Period
Type: Scalar
Units: None
Description: The forecast period is a number of timesteps, including the current simulation timestep, that is used in the algorithms for calculating forecasted hydrology, regulation discharge and flood releases. This can be propagated from a computational subbasin of which the control point is a member.
Information: This slot must be input and greater than or equal to 1. If a Forecast Period is not necessary, input a value of 1.
I/O: Required Input
Note:  If the specified reservoir is disabled and is set to Pass Inflows, no diversion request lookup is possible. See “Diversions Based on Disabled Reservoirs” in USACE‑SWD Modeling Techniques for details on the behavior in this situation.
The Reservoir Level Lookup method executes at the beginning of each timestep. For each timestep (t) in the forecast period, the Diversion Request Reservoir’s previous timestep’s (current timestep - 1) operating level and the forecast timestep’s date (t) will be used to look up the diversion request value in the Level vs Diversion Request slot. This value is set on the Diversion Requested and Depletion Requested slot. Because the method uses the same operating level (from the previous timestep) for all timesteps in the forecast period, it is an approximation but allows the object to solve throughout the forecast period.
* Specify Scheduled Requests
The Specify Scheduled Requests method sets the Diversion Requested and Depletion Requested slots at the beginning of the run to the scheduled values. When the water user solves, it computes the amount of the depletion schedule that was cutback and the amount of the depletion schedule that couldn’t be met. This allows you to track both an initial scheduled amount (as either a series or periodic relationship) and then reduce the schedule to the requests. Typically this reduction is performed using rules. The water user then computes the various depletion shortage computations.
Slots Specific to This Method
Diversion Schedule
Type: Series Slot with Periodic Input
Units: Flow
Description: The desired diversion before any cutback, curtailment or adjustments are made.
I/O: Input as either a Series or a Periodic relationship
Depletion Schedule
Type: Series Slot with Periodic Input
Units: Flow
Description: The desired diversion before any cutback, curtailment or adjustments are made.
I/O: Input as either a Series or a Periodic relationship
Depletion Schedule Cutback
Type: Series Slot
Units: Flow
Description: The difference between the Depletion Schedule and the Depletion Requested. This represents the amount that the schedule was adjusted to get to the request.
Information:
I/O: Output Only
Depletion Schedule Shortage
Type: Series Slot
Units: Flow
Description: The difference between the Depletion Schedule and the Depletion. A positive number indicates shortage, while a negative number indicates surplus.
Information:
I/O: Output only
The Specify Scheduled Requests method executes once at the beginning of the run for all timesteps in the run. The values in the Diversion Schedule and Depletion Schedule are copied to the Diversion Requested and Depletion Requested slots, respectively. Since these values are set at the beginning of the run, they are set when the controller is at priority 0 (in RBS) and the O flag. Therefore any rule executed later in the run can overwrite the values.
Shortage Computations
When the Specify Scheduled Requests is selected, additional shortage terms are computed as follows.
• Stand Alone or part of a Sequential Agg Diversion Site: At the end of the dispatch method the following are computed (see “Solve given Diversion Requested” or “Solve Sequential given Diversion Requested”).
• Part of a Lumped Agg Diversion Site: When the aggregate dispatches, it computes the following on each water user (see “Process Lumped given Diversion Requested” for details):
Table 28.1 provides sample numbers, which help to illustrate these complex computations. The variables in Bold text are part of this method. “NA” indicates it is not a slot on that object.
 
Table 28.1  Example shortage calculation numbers
 
 
Lumped Agg Diversion Site with one water user element
Variable
WU Stand Alone / Sequential
Agg
WU element
Diversion Schedule
1000
NA
1000
Depletion Schedule
800
NA
800
Diversion Request
(rule) 900
900
(rule) 900
Depletion Request
(rule) 720
720
(rule) 720
Diversion (due to available)
850
850
NA
Depletion
680
680
NA
Depletion Shortage
40
40
40
Depletion Schedule Cutback
80
NA
80
Depletion Schedule Shortage
120
NA
120
Irrigation Acreage and Evapotranspiration Rates
This category is only available when the Irrigation Requests or Irrigation Requests with Soil Moisture user method is selected in the Diversion and Depletion Request category. The category provides methods that compute Irrigated Area and Evapotranspiration Rate slots.
* Input Acreage and Rates
This is the default method. If this method is selected, Irrigated Area and Evapotranspiration Rate slots are optional inputs but required if Depletion Requested is not input.
* Aggregate Acreage and Rates
This method calculates and sets the Irrigated Area and an area-weighted Evapotranspiration Rate for use by the Irrigation Requests user method in the Diversion and Depletion Request user category.
Slots Specific to This Method
Irrigated Area by Crop
Type: AggSeries Slot
Units: area
Description: The irrigated area of each crop
Information: Each user-specified column represents a different irrigated crop acreage. These columns correspond to the crop evapotranspiration rates specified in the Evapotranspiration Rate by Crop AggSeries slot. The column labels can be changed to represent the given crop.
I/O: Input only
Evapotranspiration Rate by Crop
Type: AggSeries Slot
Units: velocity
Description: The evapotranspiration rate of each crop
Information: Each user-specified column represents a different irrigated crop evapotranspiration rate as volume per area per time. These columns correspond to the crops specified in the Irrigated Area by Crop AggSeries slot. The column labels can be changed to represent the given crop.
I/O: Input only
The method will calculate and set the Irrigated Area and an area-weighted Evapotranspiration Rate in the Irrigation Requests user method in the Diversion and Depletion Request user category on the Water User object. Solution logic for the Aggregate Acreage and Rates method proceeds as follows:
Given the Crop-specific Irrigation Area and the Crop-specific Evapotranspiration Rate slots with columns 0 to n, compute the following:
If Irrigated Area is 0, meaning no irrigation is occurring, compute the following:
Otherwise:
Limit Diversion
This category is only available when either Periodic Diversion Request or Reservoir Level Lookup is selected in the Diversion and Depletion Request category. The information added by these methods is used by a pre-defined RPL function called ComputeReservoirDiversions to determine reservoir diversions; see “ComputeReservoirDiversions” in RiverWare Policy Language (RPL) for details.
* None
There are no slots or calculation associated with this method.
* Limit by Reservoir Level
This method adds the Demand Reservoir slot. This slot is used to specify the reservoir that is receiving the diverted water (this water will pass through the Water User object and into the reservoir via the Return Flow slot). If this method is selected, the RPL function ComputeReservoirDiversions that computes the Supply From Reservoirs slot values will not compute a diversion if the Demand Reservoir is in the flood pool or if its level is higher than the supply reservoir. See “ComputeReservoirDiversions” in RiverWare Policy Language (RPL) for details.
Slots Specific to This Method
Demand Reservoir
Type: List Slot
Units: None
Description: The demand reservoir - the reservoir receiving the diverted water
Information: This slot is used by a pre-defined RPL function (ComputeReservoirDiversions) that computes multiple reservoir diversions to meet multiple demands. See “ComputeReservoirDiversions” in RiverWare Policy Language (RPL) for details.
As part of the RPL function logic, if this reservoir is in the flood pool, or if its operating level is higher than the supply reservoir, then a diversion is not made (the RPL function computes a value of zero for the associated subslot in the Supply From Reservoirs slot).
I/O: Required input
Return Flow
The Return Flow category is dependent on the user selecting either the No Structure or Sequential Structure linking structure or the Water User being stand-alone. The user methods within the Return Flow category specify how the return flow will be calculated for each Water User. The user has the option of linking the return flow back to the diverted object or elsewhere along the system.
These methods are executed after the Diversion slot has been set.
* None
None is an invalid method and an error will be posted and the run aborted when the user tries to run a model with None selected in the Return Flow category.
Note:  This is the default method for the Return Flow category.
* Fractional Return Flow
The Fractional Return Flow method calculates the return flow based on a user input fraction. The input fraction (Fractional Return Flow) is representative of the amount of flow that is not consumed by the Water User.
Slots Specific to This Method
Fraction Return Flow
Type: Series Slot
Units: Fraction
Description: fraction of the diverted flow that is not consumed by the Water User
Information:  
I/O: Required Input
Return Flow
Type: Series Slot
Units: Flow
Description: amount of diverted water not consumed by Water User
Information:  
I/O: Output only
This user method performs very simple calculations. The Return Flow is calculated as follows:
The Depletion (or amount of water consumed by the water user) is calculated as follows:
The above calculations are only performed if the Fractional Return Flow is known. If the Fractional Return Flow is not known, a RiverWare error is posted and the run is aborted.
* Proportional Shortage
The Proportional Shortage Method computes the Return Flow based on the ratio of Diversion to Diversion Requested and the Depletion Requested.
Slots Specific to This Method
Return Flow
Type: Series Slot
Units: Flow
Description: amount of diverted water not consumed by the Water User
Information:  
I/O: Output only
This method uses a set of simple calculations and logical expressions to determine the Return Flow.
The delivered fraction (a local variable) is determined as follows. If the Diversion Requested is equal to 0.0, the delivered fraction is set equal to 1.0. If the Diversion Requested is not equal to 0.0, the delivered fraction is set as follows:
After the delivered fraction is determined, determine the Depletion, as follows:
The Return Flow is then calculated as follows:
* Proportional Shortage with Soil Moisture
This method uses the diverted water to first meet Depletion Requested. If that is not sufficient, then Soil Moisture can be used to meet the Depletion Requested. This method also tracks the volume of water stored in the soil moisture.
This method is only available for stand alone water users and water user elements that are part of a No Structure or Sequential structure Agg Diversion site. Also, you must select the Irrigation Requests with Soil Moisture or Irrigation Requests with Soil Moisture method.
See “Irrigation Requests with Soil Moisture” for a diagram of the Soil Moisture slots.
Slots Specific to This Method
Available Soil Moisture Fraction
Type: Series
Units: Fraction
Description: The fraction (decimal or percentage) of moisture available. This is computed as the moisture in the soil divided by the maximum soil moisture volume
Information:
I/O: Output Only
Crop Usage
Type: Series
Units: Flow
Description: The amount of water used by the crops. This includes depletion of delivered water and soil moisture usage, but not supplemental flow.
Information:  
I/O: Output only
Crop Shortage
Type: Series
Units: Flow
Description: The amount of crop demand that is not met by either diversions or soil moisture.
Information:  
I/O: Output only
Consumptive Use from Delivered Flow
Type: Series Slot
Units: Flow
Description: The portion of the consumed water that came from the Diversion.
Information: This is identical to Depletion.
I/O: Output Only
Consumptive Use from Soil Moisture
Type: Series Slot
Units: Flow
Description: The portion of the consumed water that came from the soil moisture
Information:  
I/O: Output Only
Type: Not Linkable
Delivered Flow
Type: Series Slot
Units: Flow
Description: The portion of the diverted flow that is delivered to the fields and is available for crops or to refill the soil moisture.
Information: This is computed as the Diversion minus the Incidental Loss.
I/O: Output only
Diversion Request for Crop
Type: Series Slot
Units: Flow
Description: The requested diversion to meet crop depletion
Information: This is computed by the Irrigation Requests with Soil Moisture method. See “Irrigation Requests with Soil Moisture”.
I/O: Output only
Efficiency including Soil Moisture
Type: Series Slot
Units: Fraction
Description: Efficiency calculation that includes the flow to the soil moisture.
Information: It shows how water is used beneficially since water stored in soil moisture will be consumed later by the crop. This slot is only used for informational purposes and is not used in further calculations.
I/O: Output only
Incidental Loss
Type: Series Slot
Units: Flow
Description: The portion of the Diversion that is lost due to the incidental loss rate.
Information:  
I/O: Output only
Incidental Loss Rate
Type: Table Slot
Units: Fraction
Description: Losses in the water distribution system.
Information: Expressed as a fraction of the flow.
I/O: Optional; if not specified, zero is assumed.
Irrigated Area
Type: Series Slot
Units: Area
Description: Surface area of the land to be irrigated
Information:  
I/O: Specified according to the selected method in the Irrigation Acreage and Evapotranspiration rates category. See “Irrigation Acreage and Evapotranspiration Rates”.
Maximum Soil Moisture
Type: Scalar
Units: Length
Description: The depth of water that the soil can hold.
Information:  
I/O: Required Input
Maximum Infiltration Rate
Type: Scalar
Units: Velocity (Length per Time)
Description: Maximum depth of water that can be absorbed by the soil
Information: A valid value must be specified or an error will occur at the beginning of run.
I/O: Required Input
RETURN FLOW
Type: Series Slot
Units: FLOW
Description: Amount of diverted water not consumed by the Water User
Information:  
I/O: Output only
Soil Moisture
Type: Series Slot
Units: Volume
Description: This slot tracks the volume of soil moisture water in the soil at each timestep in the run.
Information: For the initial timestep, this slot must be valid. If this slot is not input, it will be computed as the Maximum Soil Moisture times the Irrigated Area at the initial timestep. That is, the soil moisture starts full.
I/O: Typically Output for run timesteps.
Soil Moisture Demand
Type: Series Slot
Units: Flow
Description: The flow necessary to refill the soil moisture to capacity.
Information:  
I/O: Output only
Soil Moisture Fill Efficiency
Type: Series Slot with Periodic Input
Units: Fraction
Description: The fraction of the flow applied for soil moisture refill that is not absorbed.
Information: For example, if you are only refilling the soil moisture, you may apply 100 cfs, but 5 cfs is not absorbed even though max infiltration indicated it could absorb 200cfs. The Soil Moisture Fill Efficiency would be 0.95.
I/O: Optional input. If not specified, it is assumed to be zero
Soil Moisture Flow
Type: Series
Units: Flow
Description: The flow into or out of the soil moisture.
Information: A positive number indicates flow into the soil moisture storage. A negative number indicates the soil moisture is being used to meet crop demands.
I/O: Output only
Surface Runoff
Type: Series
Units: Flow
Description: The water that runs off the field because the maximum infiltration rate has been exceeded. This water never enters the soil.
Information: If the Surface Runoff slot is linked to a slot on another object it is not included in the total Return Flow. If the Surface Runoff is not linked, the Surface Runoff is included as part of the total Return Flow.
I/O: Output only
Excess Effective Precipitation
Type: Series with Periodic Input
Units: Velocity (length/time)
Description: Excess means effective precipitation that typically cannot be used by the crops. Normally, effective precipitation is subtracted from the crop demand to compute a net Depletion Requested. However, in some instances the effective precipitation is greater than what the crops could use within a given time step. Therefore, a value for excess effective precipitation would likely be input only when input Depletion Requested is zero (because the crop demand would have been met by the non-excess portion of the effective precipitation). Excess Effective Precipitation goes towards filling the soil moisture column until the available capacity is reached. Any remaining excess effective precipitation that cannot be stored in the soil moisture column is added to return flow
Information: This value is multiplied by the irrigated acreage to compute a flow.
I/O: Input or set by a rule. It is assumed to be zero if not input.
Excess Effective Precipitation Flow
Type: Series
Units: Flow
Description: The flow rate that represents the excess effective precipitation
Information: Excess Effective Precipitation Flow = Excess Effective Precipitation * Irrigated Area
I/O: Output only
The Proportional Shortage with Soil Moisture Return Flow method does the following.
First, compute how much of diversion is lost due to conveyance or incidental loss.
Calculate how much of the diverted flow is actually delivered, as follows:
Calculate the Excess Effective Precipitation flow as follows:
Calculate the temporary variable flowToIrrigatedArea as follows. This is the flow applied to the field.
Compute the maximum infiltration flow intermediate variable, as follows:
Compute the flow the is above the maxInfiltrationFlow. This water does not absorb and runs directly off the field’s surface.
Compute the flow that infiltrates to the soil, as follows:
Compute the Depletion as follows. Depletion is limited by the maxInfiltrationFlow as it cannot use more than is infiltrated.
Calculate the initial return flow intermediate value as follows. This will occur for any diversion even when storing soil moisture.
Calculate the initial crop shortage as follows. This is the amount of the depletion requested that is not met by diverted water.
Calculate Soil Moisture Flow as follows:
IF (cropShortageInitial > 0)
This is negative indicating water is moving from the soil moisture to the crops.
ELSE
Extra water may have been diverted (if the demand factor was 0, or Diversion was specified) or there may be excess effective precipitation. The above equation uses the Soil Moisture Demand, so it can refill the soil moisture, even if the demand factor is zero. When water is applied for soil moisture, there is some that is returned, according to the Soil Moisture Fill Efficiency.
END IF
Calculate final Return Flow as follows. If the Surface Runoff slot is linked to another object it is not included in the total Return Flow.
If this Surface Runoff is not linked, the Surface Runoff is included as part of the total Return Flow, as follows:
Calculate Soil Moisture and Available Fraction as follows:
Diversion Shortage:
Depletion Shortage:
Compute total crop usage and shortage as follows:
Finally compute summary variables, as follows:
* Variable Efficiency
The Variable Efficiency method computes the Return Flow based on an efficiency driven approach. This method (or Variable Efficiency with Soil Moisture) must be selected if the user wishes to use the SW GW Efficiency Split method in the Return Flow Split category.
Slots Specific to This Method
Efficiency
Type: Series Slot
Units: Fraction
Description: amount of water depleted per unit water diverted for a given timestep
Information: Expressed as a fraction.
I/O: Output only
Maximum Efficiency
Type: Table Slot
Units: Fraction
Description: maximum amount of water depleted per unit water diverted by the Water User
Information: Expressed as a fraction.
I/O: Required Input
Return Flow
Type: Series Slot
Units: Flow
Description: amount of diverted water not consumed by the Water User
Information:  
I/O: Output only
The engineering algorithm associated with this method is given below.
The first step in this algorithm is to check that the Maximum Efficiency is greater than the ratio of Depletion Requested to Diversion Requested. If it is not, a RiverWare error is posted and the run is aborted. If Depletion Requested is not known, it is assumed to be the same as Diversion Requested.
If the Maximum Efficiency is greater than the ratio of Depletion Requested to Diversion Requested, the Efficiency is calculated as follows:
If the calculated Efficiency is greater than the Maximum Efficiency, the Efficiency is reset to value of the Maximum Efficiency.
The Depletion is calculated as follows:
After the Depletion has been calculated, it is used to calculate the Return Flow.
Note:  This method must be selected to use the Split Return Efficiency method in the Return Flow Split category.)
* Variable Efficiency with Soil Moisture
The Variable Efficiency with Soil Moisture method computes the Return Flow based on an efficiency driven approach. Diverted water first meets Depletion Requested. If that is not sufficient, then Soil Moisture can be used to meet the Depletion Requested. This method also tracks the volume of water stored in the soil moisture.
This method is only available for stand alone water users and water user elements that are part of a No Structure or Sequential structure Agg Diversion site. Also, you must select the Irrigation Requests with Soil Moisture method.
See “Irrigation Requests with Soil Moisture” for a diagram of the use of Soil Moisture slots.
Slots Specific to This Method
Efficiency
Type: Series Slot
Units: Fraction
Description: amount of water depleted per unit water diverted for a given timestep
Information: Expressed as a fraction.
I/O: Output only
Efficiency including Soil Moisture
Type: Series Slot
Units: Fraction
Description: Efficiency calculation that includes the flow to the soil moisture.
Information: It shows how water is used beneficially since water stored in soil moisture will be consumed later by the crop. This slot is only used for informational purposes and is not used in further calculations.
I/O: Output only
Available Soil Moisture Fraction
Type: Series
Units: Fraction
Description: The fraction (decimal or percentage) of moisture available. This is computed as the moisture in the soil divided by the maximum soil moisture volume
Information:
I/O: Output Only
Crop Usage
Type: Series
Units: Flow
Description: The amount of water used by the crops. This includes depletion of delivered water and soil moisture usage, but not supplemental flow.
Information:  
I/O: Output only
Crop Shortage
Type: Series
Units: Flow
Description: The amount of crop demand that is not met by either diversions or soil moisture.
Information:  
I/O: Output only
Consumptive Use from Delivered Flow
Type: Series Slot
Units: Flow
Description: The portion of the consumed water that came from the Diversion.
Information: This is identical to Depletion.
I/O: Output Only
Consumptive Use from Soil Moisture
Type: Series Slot
Units: Flow
Description: The portion of the consumed water that came from the soil moisture
Information:  
I/O: Output Only
Delivered Flow
Type: Series Slot
Units: Flow
Description: The portion of the diverted flow that is delivered to the fields and is available for crops or to refill the soil moisture.
Information: This is computed as the Diversion minus the Incidental Loss.
I/O: Output only
Diversion Request for Crop
Type: Series Slot
Units: Flow
Description: The requested diversion to meet crop depletion
Information: This is computed by the Irrigation Requests with Soil Moisture method; see “Irrigation Requests with Soil Moisture”.
I/O: Output only
Incidental Loss
Type: Series Slot
Units: Flow
Description: The portion of the Diversion that is lost due to the incidental loss rate.
Information:  
I/O: Output only
Incidental Loss Rate
Type: Table Slot
Units: Fraction
Description: Losses in the water distribution system.
Information: Expressed as a fraction of the flow.
I/O: Optional; if not specified, zero is assumed.
Irrigated Area
Type: Series Slot
Units: Area
Description: Surface area of the land to be irrigated
Information:  
I/O: Specified according to the selected method in the Irrigation Acreage and Evapotranspiration Rates category; see “Irrigation Acreage and Evapotranspiration Rates”.
Maximum Soil Moisture
Type: Scalar
Units: Length
Description: The depth of water that the soil can hold.
Information:  
I/O: Required Input
Maximum Infiltration Rate
Type: Scalar
Units: Velocity (Length per Time)
Description: Maximum depth of water that can be absorbed by the soil
Information: A valid value must be specified or an error will occur at the beginning of run.
I/O: Required Input
RETURN FLOW
Type: Series Slot
Units: FLOW
Description: Amount of diverted water not consumed by the Water User
Information:  
I/O: Output only
Soil Moisture
Type: Series Slot
Units: Volume
Description: This slot tracks the volume of soil moisture water in the soil at each timestep in the run.
Information: For the initial timestep, this slot must be valid. If this slot is not input, it will be computed as the Maximum Soil Moisture times the Irrigated Area at the initial timestep. That is, the soil moisture starts full.
I/O: Typically Output for run timesteps.
Soil Moisture Demand
Type: Series Slot
Units: Flow
Description: The flow necessary to refill the soil moisture to capacity.
Information:  
I/O: Output only
Soil Moisture Fill Efficiency
Type: Series Slot with Periodic Input
Units: Fraction
Description: The fraction of the flow applied for soil moisture refill that is not absorbed.
Information: For example, if you are only refilling the soil moisture, you may apply 100 cfs, but 5 cfs is not absorbed even though max infiltration indicated it could absorb 200cfs. The Soil Moisture Fill Efficiency would be 0.95.
I/O: Optional input. If not specified, it is assumed to be zero
Soil Moisture Flow
Type: Series
Units: Flow
Description: The flow into or out of the soil moisture.
Information: A positive number indicates flow into the soil moisture storage. A negative number indicates the soil moisture is being used to meet crop demands.
I/O: Output only
Surface Runoff
Type: Series
Units: Flow
Description: The water that runs off the field because the maximum infiltration rate has been exceeded. This water never enters the soil.
Information: If the Surface Runoff slot is linked to a slot on another object it is not included in the total Return Flow. If the Surface Runoff is not linked, the Surface Runoff is included as part of the total Return Flow.
I/O: Output only
Excess Effective Precipitation
Type: Series
Units: Velocity (length/time)
Description: Excess means effective precipitation that typically cannot be used by the crops. Normally, effective precipitation is subtracted from the crop demand to compute a net Depletion Requested. However, in some instances the effective precipitation is greater than what the crops could use within a given time step. Therefore, a value for excess effective precipitation would likely be input only when input Depletion Requested is zero (because the crop demand would have been met by the non-excess portion of the effective precipitation). Excess Effective Precipitation goes towards filling the soil moisture column until the available capacity is reached. Any remaining excess effective precipitation that cannot be stored in the soil moisture column is added to return flow
Information: This value is multiplied by the irrigated acreage to compute a flow.
I/O: Input or set by a rule. It is assumed to be zero if not input.
Excess Effective Precipitation Flow
Type: Series
Units: Flow
Description: The flow rate that represents the excess effective precipitation
Information: Excess Effective Precipitation Flow = Excess Effective Precipitation * Irrigated Area
I/O: Output only
The Variable Efficiency with Soil Moisture Return Flow method proceeds as follows.
First, compute how much of diversion is lost due to conveyance or incidental loss.
Calculate how much of the diverted flow is delivered, as follows:
Calculate the Excess Effective Precipitation flow as follows:
Calculate the temporary variable flowToIrrigatedArea. This is the flow applied to the field:
Compute the maximum infiltration flow intermediate variable as follows:
;
Compute the flow the is above the maxInfiltrationFlow. This water does not absorb and runs directly off the field’s surface.
Compute the flow that infiltrates to the soil, as follows:
The Efficiency is calculated as follows:
Thus, the Efficiency should always be between the Min and Max Efficiency, unless limited by max infiltration. If limited by max infiltration, the efficiency can be less than the minimum.
Compute the Depletion. Depletion is limited by the maxinfiltrationFlow as it cannot use more than is infiltrated.
Calculate the initial return flow intermediate value. This will occur for any diversion even when storing soil moisture. This water enters the soil but is not consumed.
Calculate the initial crop shortage as follows. This is the amount of the depletion requested that is not met by diverted water.
Calculate Soil Moisture Flow as follows:
IF (cropShortageInitial > 0)
This is negative indicating water is moving from the soil moisture to the crops.
ELSE
Extra water may have been diverted (if the demand factor was 0, or Diversion was specified). The above equation uses the Soil Moisture Demand, so it can refill the soil moisture, even if the demand factor is zero. When water is applied for soil moisture, there is some that is returned, according to the Soil Moisture Fill Efficiency.
END IF
Calculate final Return Flow as follows. If the Surface Runoff slot is linked to another object it is not included in the total Return Flow.
If this Surface Runoff is not linked, the Surface Runoff is included as part of the total Return Flow, as follows:
Calculate Soil Moisture and Available Fraction as follows:
Diversion Shortage:
Depletion Shortage:
Compute total crop usage and shortage, as follows:
Finally compute summary variables, as follows:
* Pump Back Return Flow
The Pump Back Return Flow Method allows a percentage of return flow from a water user to be returned to the diverted water for reuse. This method requires that the user selects Impulse Response as a routing method and None in the Return Flow Split category.
Slots Specific to This method
Return Flow
Type: Series Slot
Units: flow
Description: Amount of diverted water that is not consumed by the user.
I/O: Output Only
Incidental Depletions
Type: Scalar Slot
Units: fraction
Description: Single value that describes the percentage of diverted water lost to seepage or leakage.
Information: Decimal Value
I/O: Required input
Irrigated Area
Type: Series Slot
Units: Area
Description: Area of land that is irrigated by the user.
I/O: Required Input
Consumptive Irrigation Requirement
Type: Series Slot
Units: velocity
Description: Rate of water consumption per unit area of irrigated land.
I/O: Required Input
Application Efficiency
Type: Scalar Slot
Units: fraction
Description: The fraction of applied water that is consumed by the crops
I/O: Required input
Pump Back Flow
Type: Series Slot
Units: flow
Description: Amount of Routed Return Flow that is pumped back into use.
Information: This slot may be set by a rule.
I/O: Optional; if not input, Pump Back Flows are not considered
Pump Back Depletion
Type: Scalar Slot
Units: flow
Description: Table slot describing the percentage of Pump Back Flow that is depleted by the user.
I/O: Required Input
Pump Back Return
Type: Series Slot
Units: flow
Description: Amount of water (from Pump Back Flow) that is available for return after Pump Back Depletions are considered.
I/O: Output Only
Project Efficiency
Type: Scalar Slot
Units: Fraction
Information: Expressed as a fraction
I/O: Required Input
Non Applied Water
Type: Series Slot
Units: Flow
Description: Unused diverted water
I/O: Input or Set by a Rule
The routing lag coefficient is checked first to be sure that the initial value has been set to zero. This prevents an iterative loop from occurring between Return Flow, Pump Back Return, and Routed Return Flow. The Project Efficiency is also checked to make sure it is not zero. This prevents division by zero when calculating the Non Applied Water. Non Applied Water can then be input or set by a rule.
If Non Applied Water is a value less than zero, it is set equal to zero. Otherwise the value calculated above is used.
Return flow is then computed as follows:
Next, Depletion is calculated as follows:
After Return Flow and Depletion are calculated, the method checks to see if there are pump back flows. If so, return flow from above is calculated with the following equations:
The Routed Return Flow is adjusted as follows:
Fraction Return Flow Input
The Fraction Return Flow Input category is dependent on the user selecting the Fraction Return Flow method in the Return Flow category. Three methods allow the user to specify how the Fractional Return Flow (series slot) is provided data: Input Fraction, Zero Fraction, and Periodic Fraction.
The methods in this category will be called at the beginning of the run to set the Fractional Return Flow slot at each timestep.
* Input Fraction
This default method requires that the Fractional Return Flow slot be input at each timestep. RiverWare will abort with an error if the Fractional Return Flow is not input.
* Zero Fraction
At the beginning of the run, this method sets the Fractional Return Flow to 0.0 for each timestep. Hence the Return Flow will always be zero. No slots are specific to this method. RiverWare will abort with an error if the Fractional Return Flow is input.
* Periodic Fraction
This method allows the user to specify the return flow fraction using the Periodic Fraction slot. The user can input a value of 1.0 to simulate the case where all water is returned. At the beginning of the run, each timestep is used to look-up or interpolate (depending on slot configuration) the value from the Periodic Fraction and set it on the Fractional Return Flow slot. If this value is not between 0.0 and 1.0 on a given timestep, RiverWare will abort with an error. RiverWare will abort with an error if the Fractional Return Flow is input.
Slots Specific to This method
Periodic Fraction
Type: Periodic
Units: time vs fraction
Description: Fraction of the diverted flow that is not consumed by the Water User.
I/O: Input Only
Return Flow Split
The Return Flow Split category is dependent selecting either the No Structure or Sequential linking structure on the Agg Diversion Site or the Water User being stand-alone. This category contains methods which allow the user to split the return flow into surface water and groundwater components or multiple components. The None, SW GW Fractional Split and MultiReturn Fractional Split methods are available regardless of which Return Flow method is chosen. The SW GW Efficiency Split method is only available when the Variable Efficiency or Variable Efficiency with Soil Moisture methods are selected in the Return Flow category. If the user has selected Supplement Diversion in the Conjunctive Use category, the Total Return Flow, which is the sum of the Return Flow and the Supplement Return Flow, will be split into components. Otherwise, it is just the Return Flow that is split.
For each method below, the final step describes how the return flow split and the linked slots affect a sequential Agg Diversion Site. In each method, it lists the part of the return flow that contributes to the Outgoing Available Water based on linking of return flow slots.
* None
This method performs no computations.
There is no split into surface and groundwater components. The return flow is treated as a single entity. This is the default method for the Return Flow Split category.
When part of a sequential Agg Diversion Site the Return Flow Split determines method determines how much contributes to the next water user element. If using a Conjunctive Use method:
• If the Total Return Flow is linked, then the Total Return Flow is not included in the outgoing available flow.
• If the Total Return Flow is not linked, Return Flow is included in the outgoing available flow.
If not using a Conjunctive Use method:
• If the Return Flow is linked, then the Return Flow is not included in the outgoing available flow.
• If the Return Flow is not linked, Return Flow is included in the outgoing available flow.
* SW GW Fractional Split
The SW GW Fractional Split method splits the Return Flow (plus Supplement Return Flow if applicable) into surface water and groundwater components based on a user input fraction.
Slots Specific to This Method
Fraction GW Return Flow
Type: Series Slot
Units: Fraction
Description: amount of groundwater return flow per unit total return flow
Information: Expressed as a fraction.
I/O: Optional; Required when GW Return Flow and Surface Return Flow are not input.
GW Return Flow
Type: Series Slot
Units: Flow
Description: amount of return flow to groundwater
Information:  
I/O: Optional; Required when Fraction GW Return Flow and Surface Return Flow are not input.
Surface Return Flow
Type: Series Slot
Units: Flow
Description: amount of return flow to surface water
Information:  
I/O: Optional; Required when Fraction GW Return Flow and GW Return Flow are not input.
If the total return flow (sum of Return Flow and Supplement Return Flow) is equal to 0.0, both the GW Return Flow and the Surface Return Flow are set equal to 0.0. If the total return flow is not equal to 0.0 and Surface Return Flow is input (assuming both Fraction GW Return Flow and GW Return Flow are not input), GW Return is calculated by the following equation:
Fraction GW Return Flow is then calculated as follows:
If GW Return Flow is input and both Fraction GW Return Flow and Surface Return Flow are not input, Surface Return Flow is calculated as follows:
Fraction GW Return Flow is then calculated as follows:
If both Surface Return Flow and GW Return Flow are NOT input, the following steps are taken: If the total return flow is not equal to 0.0 and the Fraction GW Return Flow is input (and both GW Return Flow and Surface Return Flow are not input), the following equations are used to calculate the GW Return Flow and the Surface Return Flow. The GW Return Flow is calculated as follows:
The Surface Return Flow is the difference between the total return flow and the GW Return Flow, as follows:
When part of a sequential Agg Diversion Site, the Surface Return Flow is included in the outgoing available flow when Surface Return Flow is not linked. If Surface Return Flow is linked, it goes elsewhere and is not available for downstream elements.
* SW GW Efficiency Split
The SW GW Efficiency Split method is available only when the Variable Efficiency or Variable Efficiency with Soil Moisture methods are selected in the Return Flow category. The Efficiency value calculated from the Variable Efficiency method is used to determine the portion of return flow that is groundwater and the portion that is surface water.
Slots Specific to This Method
GW Return Flow
Type: Series Slot
Units: Flow
Description: the amount of return flow to groundwater
Information:  
I/O: Optional.
GW Split Adjust Factor
Type: Table Slot
Units: Fraction
Description: amount of groundwater return flow per unit total return flow
Information:  
I/O: Optional; Set to 1.0 if not input.
Surface Return Flow
Type: Series Slot
Units: Flow
Description: amount of return flow to surface water
Information:  
I/O: Optional.
If Surface Return Flow is input and GW Return Flow is not input, GW Return Flow is calculated by the following Equation:
If GW Return Flow is input and Surface Return Flow is not input, Surface Return Flow is calculated by the following equation:
If both Surface Return Flow and GW Return Flow are NOT input, the following steps are taken: If the total return flow (sum of the Return Flow and Supplement Return Flow) is equal to 0.0, both the GW Return Flow and the Surface Return Flow are set equal to 0.0. If the total return flow is not equal to 0.0, the GW Return Flow and the Surface Return Flow are calculated by the following equations.
The GW Return Flow is calculated as follows:
The surface Return Flow is the difference between the total return flow and the GW Return Flow, as follows:
When part of a sequential Agg Diversion Site, the Surface Return Flow is included in the outgoing available flow when Surface Return Flow is not linked. If Surface Return Flow is linked, it goes elsewhere and is not available for downstream elements.
* Irrigated Area GW Return Rate
The Irrigated Area GW Return Rate method partitions Return Flow into GW Return Flow using irrigated area and groundwater return rate, with any remaining return flow assigned to Surface Return Flow.
Slots Specific to This Method
Irrigated Area
Type: Series Slot
Units: Area
Description: The irrigated area contributing to return flow.
Information: Also used by the Irrigated Requests method, if active
I/O: Input or Output.
Groundwater Return Rate
Type: Series Slot
Units: Velocity
Description: The rate that water percolates into the ground.
Information: This represents the volume returning to groundwater per area of irrigated land per unit of time
I/O: Input only.
GW Return Flow
Type: Series Slot
Units: Flow
Description: The portion of the total Return Flow that percolates into the groundwater.
Information:  
I/O: Output only.
Surface Return Flow
Type: Series Slot
Units: Flow
Description: The portion of the total return flow that remains surface water
Information:  
I/O: Output only.
If Diversion Requested is 0, meaning no irrigation is occurring:
Otherwise:
Using the user-input Groundwater Return Rate, which is constrained to be greater than or equal to 0, perform the following equation:
With the calculated total return flow (Return Flow plus Supplement Return Flow, where applicable) constraining GW Return Flow, if necessary:
When part of a sequential Agg Diversion Site, the Surface Return Flow is included in the outgoing available flow when Surface Return Flow is not linked. If Surface Return Flow is linked, it goes elsewhere and is not available for downstream elements.
* Multi Return Fractional Split
This method is used to split the return flow into multiple return flow destinations. The user specifies the portion of the total return flow that goes to each destination.
Slots Specific to This Method
Return Flow Proportion
Type: Table Slot
Units: Fraction
Description: a table giving the proportion of the total return flow that goes to each Returned Flows subslot
Information: The values in this slot should add up to 1.0. For example, if there are two columns and the total return flow is split evenly, 0.5 would go in one column and 0.5 would go in the other column. The table will have the same number of columns as the number of return flows. The columns will be added and named (by RiverWare) whenever a link is added to the Returned Flows multislot. A decimal number will be input for each column representing each return flow slot.
I/O: Required input
Returned Flows
Type: No Compute Multi Slot
Units: Flow
Description: the multiple (or split) return flows based on the Return Flow Proportion table
Information: The subslots of this multislot contain the multiple return flows. A subslot is created when the user links this slot to a destination object.
I/O: Output
The multiple return flows would then be calculated as follows:
where i is the column of the Return Flow Proportion table; and total return flow is the sum of Return Flow and Supplement Return Flow, where applicable.
The first column on the Returned Flows multislot is the multislot itself and is not one of the subslots. It is set as the sum of all the subslot values. Therefore it should be equal to the total return flow.
Each of the multiple return flows will be represented by a subslot in the Returned Flows multislot. A subslot is created by linking the Returned Flows slot to the destination object. Whenever a new subslot is created, a new column will be added to the Return Flow Proportion slot. The column will have the same name as the subslot so that the user can keep track of which subslot goes with which column.
When part of a sequential Agg Diversion Site, the Returned Flows are not included in the outgoing available flow. The Returned Flows are all linked, so flow goes elsewhere and is not available for downstream elements.
Return Flow Routing
The methods in the Return Flow Routing category are used to route the return flow on the Water User object. The methods available in this category are dependent upon the method selected in the Return Flow Split category.
* None
This is the default method. It performs no calculations and instantiates no new slots. The user should use this method if the Return Flow is not routed.
* Impulse Response
This method is available if the user has selected None in the Return Flow Split category. In this method the Return Flow is routed based on the impulse response method of routing. It sets values only on the dispatching timestep, i.e. current object timestep.
Slots Specific to This Method
Number of Coeffs
Type: Scalar Slot
Units: None
Description: the integer number of lag coefficients to be used in the method.
I/O: Required input
Lag Coefficients
Type: Table Slot
Units: None
Description: the impulse response lag coefficients
Information: The same number of coefficients must be input as the value in the Number of Coeffs slot. The input will be in rows.
I/O: Required input
Routed Return Flow
Type: Series Slot
Units: Flow
Description: the routed return flow
Information: The return flows will be set in the Return Flow slot and then routed to this slot.
I/O: Output
The Routed Return Flow will be calculated as follows:
In this equation, ReturnFlowt is either the Return Flow slot or the Total Return Flow, when supplemental diversions are used.
When part of a sequential Agg Diversion Site, the Routed Return Flow is included in the outgoing available flow when Routed Return Flow and Return Flow are not linked. If either of these slots is linked, flow goes elsewhere and is not available for downstream elements.
* Step Response
This method is available if the user has selected None in the Return Flow Split category. In this method the Return Flow is routed based on the step response method of routing. It sets values at timesteps forward of the dispatching timestep, i.e. future timesteps.
Slots Specific to This Method
Number of Coeffs
Type: Scalar Slot
Units: None
Description: the integer number of lag coefficients to be used in the method.
I/O: Required input
Lag Coefficients
Type: Table Slot
Units: None
Description: the impulse response lag coefficients
Information: The same number of coefficients must be input as the value in the Number of Coeffs slot. The input will be in rows.
I/O: Required input
Routed Return Flow
Type: Series Slot
Units: Flow
Description: the routed return flow
Information: The return flows will be set in the Return Flow slot and then routed to this slot.
I/O: Output
Future Routing Timesteps
Type: Scalar
Units: None
Description: The number of timesteps in the future (i.e. past the timestep at which the object is dispatching) at which Routed Return Flow will be computed and set.
Information: This slot must be input and greater than or equal to 1. If you do not want it to set future timesteps, input a value of 1.
I/O: Required Input
Information: Not Linkable
The calculations for this method are similar to the Impulse Response method, but this method sets values out into the future, as follows:
nFutureTimesteps = Min ( Future Routing Timesteps, Number of Coeffs )
For each timestep k from (t to (t + nFutureTimesteps - 1))
End for
In this equation, ReturnFlowk is either the Return Flow slot or the Total Return Flow, when supplemental diversions are used.
Thus, the method computes and sets Routed Return Flows forward nFutureTimesteps.
In the situation where the method is looking for a Return Flow for a timestep that is actually past the dispatching timestep and this value is not valid, this Return Flow is assumed to be zero. If the Return Flow is not valid for a previous timestep, the calculation will exit the method and post a warning message.
If the Routed Return Flow is input or specified by a rule, that value is used and the routing is not performed.
When part of a sequential Agg Diversion Site, the Routed Return Flow is included in the outgoing available flow when Routed Return Flow and Return Flow are not linked. If either of these slots is linked, flow goes elsewhere and is not available for downstream elements
* SW GW Impulse Response
This method is available when either SW GW Fractional Split or SW GW Efficiency Split is selected in the Return Flow Split category.
Slots Specific to This Method
Number of SW GW Coeffs
Type: Table Slot
Units: None
Description: a two column table slot giving the number of lag coefficients to be used in the routing method
Information: The first column will give the number of coefficients for the surface return flow and the second column will give the number of coefficients for the groundwater return flow.
I/O: Required input
SW GW Lag Coefficients
Type: Table Slot
Units: None
Description: the impulse response lag coefficients for both surface water and groundwater return flows
Information: The first column will contain the lag coefficients for the surface water return flow. There must be the same number of coefficients in this column as the value in the first column of the Number of Coeffs slot. The second column will contain the lag coefficients for the groundwater return flow. There must be the same number of coefficients in this column as the value in the second column of the Number of Coeffs slot.
I/O: Required input
SW Routed Return
Type: Series Slot
Units: Flow
Description: the routed surface water return flow
I/O: This slot is computed by the routing method.
I/O: Output
GW Routed Return
Type: Series Slot
Units: Flow
Description: the routed groundwater return flow
Information: This slot is computed by the routing method.
I/O: Output
The return flows will be calculated as follows:
When part of a sequential Agg Diversion Site, the SW Routed Return Flow is included in the outgoing available flow when SW Routed Return Flow and Return Flow are not linked. If either of these slots is linked, flow goes elsewhere and is not available for downstream elements
* Multi Split Impulse Response
This method is available when Multi Return Fractional Split method is selected in the Return Flow Split category. Each split return flow is routed (using different parameters) by the impulse response method of routing. This method sets values only at the timestep at which the water user is dispatching.
Slots Specific to This Method
Number of MR Coeffs
Type: Scalar Slot
Units: None
Description: the integer number of lag coefficients to be used in the method.
Information: A column will be added automatically for each of the split return flows. The name of the column is used to match it with the appropriate subslot in the Returned Flows slot. Each column corresponds to the number of lag coefficients to be used for that particular split return flow.
I/O: Required input
Multi Return Lag Coeffs
Type: Table Slot
Units: None
Description: the impulse response lag coefficients
Information: The same number of coefficients must be input in each column as the value in the corresponding column in the Number of MR Coeffs slot. The columns are added and named automatically as a new subslot is added to the Returned Flows slot.
I/O: Required input
PreRouted Return Flows
Type: Agg Series Slot
Units: Flow
Description: the return flows prior to routing
Information: A column will be added automatically for every subslot in the Returned Flows multislot. The name of the column is used to match it with the appropriate subslot in the Returned Flows slot.
I/O: Output (Can be input prior to the Start date to set initial values for impulse response routing).
Subslots in the Returned Flows slot are created when a link is made from this slot to the destination object. When a subslot is created, a corresponding column in the Number of MR Coeffs, Multi Return Lag Coeffs and PreRouted Return Flows slots is added automatically. The new columns have the same name as the subslot so you know which column goes with which subslot.
The impulse response calculations are performed for every return flow split; the method is nested in a loop that executes for every column in the Number of MR Coeffs slot. The Returned Flows are calculated as follows:
The first column on the Returned Flows multislot is the multislot itself and is not one of the subslots. It is set as the sum of all the subslot values.
* Multi Split Step Response
This method is available when Multi Return Fractional Split method is selected in the Return Flow Split category. Each split return flow is routed (using different parameters) by the step response method of routing. It sets values at timesteps forward of the dispatching timestep, i.e. future timesteps.
Slots Specific to This Method
Number of MR Coeffs
Type: Scalar Slot
Units: None
Description: the integer number of lag coefficients to be used in the method.
Information: A column will be added automatically for each of the split return flows. The name of the column is used to match it with the appropriate subslot in the Returned Flows slot. Each column corresponds to the number of lag coefficients to be used for that particular split return flow.
I/O: Required input
Multi Return Lag Coeffs
Type: Table Slot
Units: None
Description: the impulse response lag coefficients
Information: The same number of coefficients must be input in each column as the value in the corresponding column in the Number of MR Coeffs slot. The columns are added and named automatically as a new subslot is added to the Returned Flows slot.
I/O: Required input
PreRouted Return Flows
Type: Agg Series Slot
Units: Flow
Description: the return flows prior to routing
Information: A column will be added automatically for every subslot in the Returned Flows multislot. The name of the column is used to match it with the appropriate subslot in the Returned Flows slot.
I/O: Output or input prior to the Start date to set initial values for step response routing).
Future Routing Timesteps
Type: Scalar
Units: None
Description: The number of timesteps in the future (i.e. past the timestep at which the object is dispatching) at which Routed Return Flow will be computed and set.
Information: This slot must be an input integer and greater than or equal to 1. If you do not want it to set future timesteps, input a value of 1.
I/O: Required Input
Information: Not Linkable
The first column on the Returned Flows multislot is the multislot itself and is not one of the subslots. It is set as the sum of all the subslot values.
Subslots in the Returned Flows slot are created when a link is made from this slot to the destination object. When a subslot is created, a corresponding column in the Number of MR Coeffs, Multi Return Lag Coeffs and PreRouted Return Flows slots will be added automatically. The new columns will have the same name as the subslot so the user knows which column goes with which subslot.
The step response calculations are performed for every return flow split, the method is nested in a loop that executes for every column (i) in the Number of MR Coeffs slot.
The calculations for this method are similar to the Multi Split Impulse Response method, but this method sets values into the future.
nFutureTimesteps = Min ( Future Routing Timesteps, Number of Coeffs )
For each timestep k from (t to (t + nFutureTimesteps - 1))
End for
Thus, the method computes and sets Routed Return Flows forward nFutureTimesteps.
When the method is looking for a PreRouted Return Flow for a timestep that is past the dispatching timestep and the value is not valid, the PreRouted Return Flow is assumed to be zero. If the PreRouted Return Flow is not valid for a previous timestep, the calculation will exit the method and post a warning message. No Returned Flows will be set.
If the slot linked to the Returned Flows slot is input or set by a rule, the computed Returned Flow is not computed for that timestep as the value is already specified.
Conjunctive Use
The Conjunctive Use methods are used to model diversions from a different source (E.g. groundwater) to supplement surface water diversions.
* None
This is the default user method. It performs no calculations and has no slots specifically associated with it.
* Supplement Diversion
This method functions differently for the three linking structures. There is also a different set of slots for each of the linking structures.
The slot list for the default (No Structure) linking structure or for a standalone Water User is as follows.
Slots Specific to This Method
Available Supplemental Water
Type: Series Slot
Units: Flow
Description: represents the amount of water available to supplement surface water diversion
Information:  
I/O: Required input; however, it can by set through a link.
Consumption
Type: Series Slot
Units: Flow
Description: total amount of water consumed/used by the Water User
Information:  
I/O: Output only
Consumption Shortage
Type: Series Slot
Units: Flow
Description: the total water shortage experienced by the crops
Information: This represents the shortage in terms of the water requested for consumption.
I/O: Output only
Supplemental Diversion
Type: Series Slot
Units: Flow
Description: the amount of water diverted from groundwater for supplemental use
Information:  
I/O: Output only
Supplement Return Flow
Type: Series Slot
Units: Flow
Description: the amount of return flow from the supplemental water
Information: Calculated by the same method that calculates return flow from surface diversions.
I/O: Output only
Supplemental Use Delivery
Type: Series Slot
Units: Flow
Description: amount of supplemental water received by the Water User
Information: For the No Structure case, this is always equal to the Supplemental Diversion.
I/O: Output only
Supplemental Use Request
Type: Series Slot
Units: Flow
Description: the amount of supplemental water requested
Information:  
I/O: Optional; If not input, it is set to the lower value of Diversion Shortage or Maximum Supplement Request.
Total Applied Water
Type: Series Slot
Units: Flow
Description: total amount of water available for consumption/use by the water user
Information:  
I/O: Output only
Total Return Flow
Type: Series Slot
Units: Flow
Description: the sum of the Return Flow and the Supplement Return Flow
Information: This value is split into surface and groundwater components if a method is selected in the Return Flow Split category.
I/O: Output only
The slot list for the sequential linking structure is given below.
Slots Specific to This Method
Consumption
Type: Series Slot
Units: Flow
Description: total amount of water consumed/used by the Water User
Information:  
I/O: Output only
Consumption Shortage
Type: Series Slot
Units: Flow
Description: the total water shortage experienced by the crops
Information: This represents the shortage in terms of the water requested for consumption.
I/O: Output only
Supplemental Diversion Priority
Type: Table Slot
Units: None
Description: an integer value which represents the Water User’s priority in supplemental water rights
Information: A low integer value indicates a high priority.
I/O: Required input
Supplement Return Flow
Type: Series Slot
Units: Flow
Description: the amount of return flow from the supplemental water
Information: Calculated by the same method that calculates return flow from surface diversions.
I/O: Output only
Supplemental Use Delivery
Type: Series Slot
Units: Flow
Description: amount of supplemental water received by the Water User
Information:  
I/O: Output only
Supplemental Use Request
Type: Series Slot
Units: Flow
Description: the amount of supplemental water requested
Information:  
I/O: Optional; if not input, it is set to the lower value of Diversion Shortage and Maximum Supplement Request.
Total Applied Water
Type: Series Slot
Units: Flow
Description: total amount of water available for consumption/use by the water user
I/O:  
Total Return Flow
Type: Series Slot
Units: Flow
Description: the sum of the Return Flow and the Supplement Return Flow
Information: This value is split into surface and groundwater components if a method is selected in the Return Flow Split category.
I/O: Output only
For both linking structures, Supplemental Use Request is set by the following equation:
(Maximum Supplement Request slot values are set by the Max Supplemental Request method.)
If the default linking structure is active, Supplemental Diversion is set by the following equation:
Supplemental Use Delivery is then set equal to Supplemental Diversion.
However, if the sequential linking structure is active, Supplemental Diversion is a slot on the Agg Diversion Site and therefore, is calculated there. The Agg Diversion Site then sets Supplemental Use Delivery on each Water User based on the Supplemental Diversion and the Supplemental Diversion Priority of each Water User. This is explained in more detail on the Agg Diversion Site object.
The following calculations are then performed regardless of the linking structure selected:
The Supplement Return Flow is then calculated by the method selected in the Return Flow category. For example, if the Fraction Return Flow method is selected, Supplement Return Flow is the product of Supplemental Use Delivery and the Fraction Return Flow. If the Variable Efficiency method is selected, the efficiency is recalculated based on the Total Applied Water. Return Flow and Depletion are then recalculated for the new Efficiency value. Supplement Return Flow is calculated by the following equation:
Consumption and Consumption Shortage are then computed.
Finally, compute the Total Return Flow, as follows:
• If the Return Flow is linked or the Supplement Return Flow is linked, the Total Return Flow is zero; both slots are linked so the flows go elsewhere.
• If the Return Flow is linked but the Supplement Return Flow is not linked, the Total Return Flow is equal to the Supplement Return Flow.
• If the Return Flow is not linked and the Supplement Return Flow is linked, the Total Return Flow is equal to the Return Flow.
• If neither Return Flow nor the Supplement Return Flow is linked, the Total Return Flow is the sum of Return Flow and Supplement Return Flow.
When the Water User is an element of a sequential Agg Diversion Site, the Outgoing Available water is set to the computed Total Return Flow. This determines how much water is available for downstream elements.
* Supplement Diversion including Soil Moisture
This method allows supplemental diversions when also modeling Soil Moisture. As a result, you must be using both the Irrigation Requests with Soil Moisture and Proportional Shortage with Soil Moisture, or Variable Efficiency with Soil Moisture method.
Note:  This method is available for any of the following conditions:
• On a stand alone Water User
• On an element of a No Structure Agg Diversion Site
• On an element of a Sequential Agg Diversion Site
It is not available on a water user on a Lumped Agg Diversion Site.
See “Irrigation Requests with Soil Moisture” for a diagram of the use of Soil Moisture slots.
Slots Specific to This Method
Available Supplemental Water
Type: Series Slot
Units: Flow
Description: represents the amount of water available to supplement surface water diversion
Information:  
I/O: This value is required for the method to solve. It is usually propagated across a link.
Consumption
Type: Series Slot
Units: Flow
Description: Total amount of water consumed/used by the Water User
Information:  
I/O: Output only
Consumption Shortage
Type: Series Slot
Units: Flow
Description: The total water shortage experienced by the crops
Information: This represents the shortage in terms of the water requested for consumption.
I/O: Output only
Consumptive Use from Supplemental
Type: Series Slot
Units: Flow
Description: The consumed water from the Supplemental Diversion
Information:  
I/O: Output Only
Irrigated Area
Type: Series Slot
Units: Area
Description: surface area of the land to be irrigated
Information:  
I/O: Specified according to the selected method in the Irrigation Acreage and Evapotranspiration Rates category; see “Irrigation Acreage and Evapotranspiration Rates”.
Maximum Soil Moisture
Type: Scalar
Units: Length
Description: The depth of water that the soil can hold.
Information:  
I/O: Required Input
Minimum Efficiency
Type: Series Slot
Units: Fraction
Description: Minimum amount of consumed flow per unit diverted flow
Information: Expressed as a fraction.
I/O: Required input
Soil Moisture
Type: Series Slot
Units: Volume
Description: This slot tracks the volume of soil moisture water in the soil at each timestep in the run.
Information: For the initial timestep, this slot must be valid. If this slot is not input, it will be computed as the Maximum Soil Moisture times the Irrigated Area at the initial timestep. That is, the soil moisture starts full.
I/O: Typically Output for run timesteps.
Supplemental Diversion
Type: Series Slot
Units: Flow
Description: The amount of water pumped from groundwater or diverted for supplemental use.
Information:  
I/O: Input, Output, or set by a rule.
Supplemental Flow to Soil Moisture
Type: Series Slot
Units: Flow
Description: The portion of the supplemental flow that goes to the soil moisture.
Information: This is only positive if Supplemental Diversion is set (input or rules) to a value larger than Supplemental Use Request and less than the infiltration limit.
I/O: Output Only
Supplemental Request Fraction
Type: Series with Periodic Input
Units: Fraction
Description: The fraction of the remaining demand that should be met with supplemental water.
Information: If not specified, it is assumed to 1.0.
I/O: Optional input as either a series or periodic relationship.
Supplement Return Flow
Type: Series Slot
Units: Flow
Description: The amount of return flow from the supplemental water
Information:  
I/O: Output only
Supplemental Runoff
Type: Series Slots
Units: Flow
Description: The amount of applied supplemental water that runs off the fields directly due to max infiltration limits.
Information: If the Supplemental Runoff slot is linked to a slot on another object it is not included in the total Return Flow. If the Supplemental Runoff is not linked, the Supplemental Runoff is included as part of the total Return Flow.
I/O: Output only
Supplemental Use Delivery
Type: Series Slot
Units: Flow
Description: amount of supplemental water received by the Water User
Information: For the No Structure case, this is always equal to the Supplemental Diversion.
I/O: Output only
Supplemental Use Request
Type: Series Slot
Units: Flow
Description: the amount of supplemental water requested
Information:  
I/O: Optional; If not input, it is set to the lower value of Diversion Shortage or Maximum Supplement Request.
Total Applied Water
Type: Series Slot
Units: Flow
Description: total amount of water available for consumption/use by the water user
Information: It is computed as the sum of Delivered Flow, Excess Effective Precipitation Flow and Supplemental Use Delivery.
I/O: Output only
Total Return Flow
Type: Series Slot
Units: Flow
Description: the sum of the Return Flow and the Supplement Return Flow
Information: This value is split into surface and groundwater components if a method is selected in the Return Flow Split category.
I/O: Output only
The following equations are executed from the dispatch method (this applies to a stand alone or No Structure water user). This method is not available on a sequential Agg Diversion Site, but the soil moisture methods above can be used.
If the Proportional Shortage with Soil Moisture method is selected, efficiencyTemp is set to the Minimum Efficiency.
If the Variable Efficiency with Soil Moisture method is selected, efficiencyTemp is set to the computed efficiency on the slot.
If Maximum Supplement Request is in use and valid:
Otherwise
Since some water has already been applied, compute the new infiltration limit.
If Supplemental Diversion is not specified (Input or set by a rule),
Otherwise, the specified Supplemental Diversion is used.
Compute any Supplemental Diversion that runs off due to the infiltration limit, as follows:
Compute a temporary variable representing the supplemental flow that infiltrates into the soil, as follows:
Next, compute the supplemental use delivery as follows:
If the Variable Efficiency with Soil Moisture method is selected, recompute the efficiencyTemp as the new
When the Proportional Shortage with Soil Moisture method is selected, efficiencyTemp continues to be the Minimum Efficiency.
Compute the initialSupplementReturnFlow as follows. This is the amount that would become return flow regardless of soil moisture.
Calculate consumed supplemental flow as follows:
Calculate remaining available for soil moisture as follows:
Calculate the new limits on soil moisture refill including the flow to fill the soil moisture and the new infiltration limit, as follows:
Calculate the supplemental flow that fills the soil moisture, as follows:
Determine the new Soil Moisture volume, as follows:
Calculate final Supplemental Return Flow.
If the Supplemental Runoff slot is linked to another object, it is not included in the total Return Flow:
Otherwise, the Supplemental Runoff is not linked, the Supplemental Runoff is included as part of the total Supplemental Return Flow:
Compute Consumption and Consumption Shortage, and set Consumptive Use from Supplemental.
Finally, compute the Total Return Flow, as follows:
• If the Return Flow is linked or the Supplement Return Flow is linked, the Total Return Flow is zero; both slots are linked so the flows go elsewhere.
• If the Return Flow is linked but the Supplement Return Flow is not linked, the Total Return Flow is equal to the Supplement Return Flow.
• If the Return Flow is not linked and the Supplement Return Flow is linked, the Total Return Flow is equal to the Return Flow.
• If neither Return Flow nor the Supplement Return Flow is linked, the Total Return Flow is the sum of Return Flow and Supplement Return Flow.
When the Water User is an element of a sequential Agg Diversion Site, the Outgoing Available water is set to the computed Total Return Flow. This determines how much water is available for downstream elements.
Max Supplemental Request
This method category is available to Water Users when the Supplement Diversion method in the Conjunctive Use category is selected. It solves for the Maximum Supplement Request slot used in Conjunctive Use calculations.
* None
This is the default user method. It performs no calculations and has no slots specifically associated with it.
* Input Max Request
This method instantiates the Maximum Supplement Request slot for user input.
Slots Specific to This Method
Maximum Supplement Request
Type: Series Slot
Units: Flow
Description: user specified maximum supplemental request
Information:  
I/O: Optional, not used if not input or set by a rule
* GW Elevation Max Request
This method calculates the Maximum Supplement Request slot value based upon groundwater elevations at the previous timestep.
Values for the Previous Groundwater Elevation slot are set somewhat differently depending on the linking structure. When the No Structure linking structure is selected or the Water User is a stand alone object, Previous Groundwater Elevation values are set by a link to a Groundwater Storage object’s Previous Groundwater Elevation slot. When the Sequential Structure is selected, a Previous Groundwater Elevation slot also becomes available on the parent Agg Diversion Site object. When this is the case, the user should link the Agg Diversion Site’s Previous Groundwater Elevation slot to the Groundwater Storage object. An automatic link exists between the Agg Diversion Site ant its elements so it is not necessary to link the Previous Groundwater Elevation slot on the Water Users for the sequential linking structure.
Slots Specific to This Method
Max Request Table
Type: Table Slot
Units: length vs. Flow
Description: user input relating groundwater elevation and maximum supplemental request
Information:  
I/O: Required input
Previous Groundwater Elevation
Type: Series Slot
Units: length
Description: previous groundwater elevation propagated across a link
Information: When the sequential linking structure is active, this slot is automatically linked to the Previous Groundwater elevation slot on the Aggregate object. Only the Aggregate object should be linked to the Groundwater Storage object. When the No Structure method is active or the Water User is a stand alone object, this slot should be linked by the user to the Groundwater Storage object
I/O: Optional; usually set by a link
Maximum Supplement Request
Type: Series Slot
Units: Flow
Description: maximum supplemental request based upon Max Request Table
Information:  
I/O: Output only
Maximum Supplement Request is calculated by interpolation of the Max Request Table using the Previous Groundwater Elevation.
Multiple Supply Sources
The Multiple Supply Sources category contains a method that adds the Supply From Reservoirs slot. This slot is used by a pre-defined RPL function (ComputeReservoirDiversions) that determines diversions from multiple reservoirs to meet the Diversion Requested on a single Water User object. In this case, the reservoir object also usually serve more than one Water User. See “ComputeReservoirDiversions” in RiverWare Policy Language (RPL) for details.
* None
There are no slots or calculation associated with this method
* Multiple Supply Reservoirs
This method adds the Supply From Reservoirs slot that is used by a RPL pre-defined function (ComputeReservoirDiversions) that computes multiple reservoir diversions. There are no calculations associated with this method. See “ComputeReservoirDiversions” in RiverWare Policy Language (RPL) for details.
Slots Specific to This Method
Supply From Reservoirs
Type: No Compute Multi Slot
Units: Flow
Description: The delivery from each reservoir that supplies the water user object
Information: A link is created to the Multi Outflow slot on each Diversion Object that connects to a possible supply reservoir. The values in this slot are determined by a pre-defined RPL function (ComputeReservoirDiversions). See “ComputeReservoirDiversions” in RiverWare Policy Language (RPL) for details.
I/O: Output only
Maximum Delivery Rates
Type: Table Slot
Units: Flow
Description: The maximum delivery rate associated with each source specified in the Supply From Reservoirs slot
Information: Each column will be dynamically generated to correspond to a subslot/link to the Supply From Reservoir slot. At beginning of run, a check will make sure there is a column and value on this slot for each subslot on the Supply From Reservoirs slot.
MODFLOW Link Category WU
This category is used to specify whether this Water User is linked to an external MODFLOW model.
* No Link to MODFLOW WU
No computations or slots are associated with the No Link to MODFLOW WU method; this is the default method for the MODFLOW Link Category WU.
* Link to MODFLOW WU
Note:  RiverWare’s connection with MODFLOW is currently not functional. This method has been disabled and cannot be selected. An error will be posted at model load if this method was previously selected. Contact CADSWES for help.
The Link to MODFLOW WU method allows the Water User object to be linked with MODFLOW. No computations or slots are associated with this method. A surface water body represented in MODFLOW may receive a surface return flow from a RiverWare Water User object. That is, the value on the Surface Return Flow slot may be transferred through the computational subbasin structure to MODFLOW when either of the Return Flow Split methods are selected and the Link to MODFLOW WU method is selected. See “Water User” for a description of the Water User specific data configuration.
Dispatch Methods
The Water User object can dispatch to solve for Diversion or can dispatch when Diversion is given.
Note:  When the Supply From Reservoir slot is in use, the Supply From Reservoir slot values are set to zero for all timesteps during begin run initialization. This allows the zero values to propagate up to the Diversion object and then to the Diversion slot on the Reservoir. This is done because every reservoir dispatch method requires the Diversion value to be known. By defaulting these values to zero, the reservoir is able to dispatch without waiting for the ComputeReservoirDiversions function to execute and set the actual diversion values on the Supply From Reservoir slot. See “ComputeReservoirDiversions” in RiverWare Policy Language (RPL) for details.
If the Return Flow slot is linked to a reservoir object, those values are also defaulted to zero for all timesteps. This is done for the same reason as described above - so the reservoir can dispatch with a zero return flow before the actual return flow value is calculated.
No Structure
The Water User object will only dispatch using these methods when the No Structure linking method is selected on an Agg Diversion Site or when the Water User is a stand alone object.
* Solve given Diversion Requested
Note:  You can typically let the selected Diversion and Depletion Request method set Diversion Requested at the beginning of the run or beginning of the timestep (or input the values). If you wish to set Diversion Requested using a rule, the rule computed Diversion Requested will overwrite the method computed value. The water user will then dispatch Solve Stand alone given Diversion Requested if Incoming Available Water is known.
Required Knowns
Required Unknowns
• Diversion
The algorithm is used to determine Diversion, Depletion, Return Flow, Diversion Shortage and Depletion Shortage when the No Structure linking method is used, or the object is stand-alone.
Diversion is set equal to the minimum of Incoming Available Water and Diversion Requested. Return Flow and Depletion are then calculated based on the user method selected in the Return Flow category. Depletion Shortage is calculated as the difference between Depletion Requested and Depletion. Diversion Shortage is calculated as the difference between Diversion and Diversion Requested.
If selected, the conjunctive use calculations are then performed.
Next, the total return flow (Return Flow plus Supplement Return Flow, when in use) are split and/or routed, using the selected methods.
When the Specify Scheduled Requests method is selected, the Depletion Schedule Cutback and Depletion Schedule Shortage are computed; see “Specify Scheduled Requests” for details.
* Solve given Diversion
Note:  You can typically specify the Diversion and the Water User will dispatch given Diversion using this dispatch method. To specify Diversion with a rule, the water user’s Incoming Available Water should not be linked or Diversion Requested should be left unknown. If Incoming Available Water is linked, the water user could dispatch Solve Stand alone given Diversion Requested depending on the timing of the setting of the required knowns.
Required Knowns
Required Unknowns
The algorithm is used to determine Depletion, Return Flow, Diversion Shortage, and Depletion Shortage when the No Structure linking method is used, or the object is stand-alone.
Return Flow and Depletion are calculated based on the user method selected in the Return Flow category. If Depletion Requested is known, Depletion Shortage is calculated as the difference between Depletion Requested and Depletion. Diversion Shortage is calculated as the difference between Diversion and Diversion Requested.
If selected, the conjunctive use calculations are then performed.
Next, the total return flow (Return Flow plus Supplement Return Flow, when in use) are split and/or routed, using the selected methods.
When the Specify Scheduled Requests method is selected, the Depletion Schedule Cutback and Depletion Schedule Shortage are computed; see “Specify Scheduled Requests” for details.
* Solve given Depletion Requested
This method is available when the Irrigation Requests with Soil Moisture method is selected.
Required Knowns
Required Unknowns
The algorithm is used to determine Diversion, Depletion, Return Flow, Diversion Shortage and Depletion Shortage when the No Structure linking method is used, or the object is stand-alone.
First, execute the per-dispatch portions of the computation to compute the Diversion Requested, Diversion Request for Crops, and Diversion Request for Soil Moisture. If Soil Moisture at the previous timestep is unknown, exit and wait for it to become known.
Diversion is set equal to the minimum of Incoming Available Water and Diversion Requested. Return Flow and Depletion are then calculated based on the user method selected in the Return Flow category. Depletion Shortage is calculated as the difference between Depletion Requested and Depletion. Diversion Shortage is calculated as the difference between Diversion and Diversion Requested.
If selected, the conjunctive use calculations are then performed.
Next, the total return flow (Return Flow plus Supplement Return Flow, when in use) are split and/or routed, using the selected methods.
Sequential Structure
The Water User will only dispatch using these methods when the Sequential Structure linking method is selected on the aggregate diversion site that contains these water user elements.
* Solve Sequential given Diversion Requested
Required Knowns
Required Unknowns
If Incoming Available Water is greater than Diversion Requested, then Diversion is set equal to Diversion Requested and a temporary variable, unusedFlow, is the difference between Incoming Available Water and Diversion. If Incoming Available Water is less than Diversion Requested, Diversion is set equal to Incoming Available Water and unusedFlow is zero.
The Depletion Shortage is calculated as the difference between Depletion Requested and Depletion. Diversion Shortage is calculated as the difference between Diversion and Diversion Requested.
The Return Flow and Depletion are calculated based on the selected user method in the Return Flow category.
When the Specify Scheduled Requests method is selected, the Depletion Schedule Cutback and Depletion Schedule Shortage are computed. See “Specify Scheduled Requests” for details.
If selected, the Conjunctive Use calculations are then performed.
Next, the total return flow (Return Flow plus Supplement Return Flow, when in use) are split using the selected Return Flow Split method and/or routed, using the selected Return Flow Routing methods.
Next, the portion of the outgoing water that is from Return Flow is computed, using a temporary variable called outgoingFromRF. This computation depends on the selected Return Flow Split method and Return Flow Routing. Basically, if the return flow slot (Surface Return Flow, Return Flow, Total Return Flow or Routed Return Flow) is linked, it is going elsewhere and not available to the next element, so it is not included in the outgoingFromRF. If the flow components are not linked, it is considered outgoingFromRF.
Finally, the Outgoing Available Water is computed as
The Outgoing Available Water propagates across a link to the Incoming Available Water for the next Water User or the Total Unused Water of the Agg Diversion Site.
* Solve Sequential given Diversion
Required Knowns
Required Unknowns
If Incoming Available Water is greater than Diversion, then a temporary variable, unusedFlow, is the difference between Incoming Available Water and Diversion. If Incoming Available Water is less than Diversion, unusedFlow is zero.
If Depletion Requested is valid, the Depletion Shortage is calculated as the difference between Depletion Requested and Depletion. Diversion Shortage is calculated as the difference between Diversion and Diversion Requested.
The Return Flow and Depletion are calculated based on the selected user method in the Return Flow category. If the return flow is split and neither Return Flow nor Surface Return Flow are linked, the value of Surface Return Flow is added to the existing Outgoing Available Water. If the return flow is not split and Return Flow is not linked, the value of Return Flow is added to the existing Outgoing Available Water.
When the Specify Scheduled Requests method is selected, the Depletion Schedule Cutback and Depletion Schedule Shortage are computed. See “Specify Scheduled Requests” for details.
If selected, the Conjunctive Use calculations are then performed.
Next, the total return flow (Return Flow plus Supplement Return Flow, when in use) are split using the selected Return Flow Split method and/or routed, using the selected Return Flow Routing methods.
Next, the portion of the outgoing water that is from Return Flow is computed, using a temporary variable called outgoingFromRF. This computation depends on the selected Return Flow Split method and Return Flow Routing. Basically, if the return flow slot (Surface Return Flow, Return Flow, Total Return Flow or Routed Return Flow) is linked, it is going elsewhere and not available to the next element, so it is not included in the outgoingFromRF. If the flow components are not linked, it is considered outgoingFromRF.
Finally, the Outgoing Available Water is computed.
The Outgoing Available Water propagates across a link to the Incoming Available Water for the next Water User or the Total Unused Water of the Agg Diversion Site.
* Solve Sequential given Depletion Requested
This method is available if the water user has the Irrigation Requests with Soil Moisture method selected.
Required Knowns
Required Unknowns
The algorithm is used to determine Diversion, Depletion, Return Flow, Diversion Shortage and Depletion Shortage when the Sequential linking method is used.
If Irrigation Requests with Soil Moisture is selected, compute the Diversion Requested, Diversion Request for Crops, and Diversion Request for Soil Moisture. If Soil Moisture at the previous timestep is unknown, exit and wait for it to become known.
If Incoming Available Water is greater than Diversion Requested, then Diversion is set equal to Diversion Requested and a temporary variable unusedFlow is the difference between Incoming Available Water and Diversion. If Incoming Available Water is less than Diversion Requested, Diversion is set equal to Incoming Available Water and unusedFlow is zero.
The Depletion Shortage is calculated as the difference between Depletion Requested and Depletion. Diversion Shortage is calculated as the difference between Diversion and Diversion Requested.
If selected, the Conjunctive Use calculations are then performed.
Next, the total return flow (Return Flow plus Supplement Return Flow, when in use) are split using the selected Return Flow Split method and/or routed, using the selected Return Flow Routing methods.
Next, the portion of the outgoing water that is from Return Flow is computed, using a temporary variable called outgoingFromRF. This computation depends on the selected Return Flow Split method and Return Flow Routing. Basically, if the return flow slot (Surface Return Flow, Return Flow, Total Return Flow or Routed Return Flow) is linked, it is going elsewhere and not available to the next element, so it is not included in the outgoingFromRF. If the flow components are not linked, it is considered outgoingFromRF.
Finally, the Outgoing Available Water is computed.
The Outgoing Available Water propagates across a link to the Incoming Available Water for the next Water User or the Total Unused Water of the Agg Diversion Site.
Lumped Structure
The Water User does not dispatch when the Lumped Structure linking method is selected on the Agg Diversion Site. But, when the Agg Diversion Site dispatches, it will set the Depletion Shortage on the element water users. See “Process Lumped given Diversion Requested” for details. Any shortage on the aggregate is shared by each water user element proportional to its Depletion Requested. When the Specify Scheduled Requests method is selected, the Depletion Schedule Cutback and Depletion Schedule Shortage are also set on the water user elements.
 
Revised: 06/03/2019