All three methods—Abiquiu, Cochiti, and Jemez Gain Loss—carry out the following steps.

For a 1 Month timestep, this can be done based on the Precipitation Volume for the month, which was set in simulation. The Precipitation Volume calculation will already account for Ice Coverage if applicable. For a 1 Day timestep, Effective Precipitation must be calculated using the cumulative sum of Precipitation Rate from the beginning of the month to the current day, and Ice Coverage is included explicitly. At a 1 Month timestep the average surface area is used, whereas the current (end of timestep) surface area is used for a 1 Day timestep.

For all following calculations, Area values for a 1 Day timestep are current (end of timestep) areas. For a 1 Month timestep, Area values are averages of the end of the previous timestep and end of the current timestep values, similarly for Ice Coverage. If Ice Coverage is not applicable based on the selected evaporation method, it is zero in the calculations below.

If the Surface Area is zero, then evapDepth and effecitvePrecipDepth are zero, and if Ice Coverage is one, then effectivePrecipDepth is zero.

Each of these values is positive for a loss. The PreRes areas are contained in the Control and PreRes Areas table slot. The results of these calculations are set in the PreReservoir Condition table series slot.

Each of these values is positive for a loss. The results of these calculations are set in the Present Condition table series slot.

The netInflowVolume will be negative if there is unidentified loss. If netInflowVolume is positive, then unidentified loss is zero. The Storage Adjustment from Elev Vol Table Change component is only included if the Time Varying Elevation Volume method is selected for the Sediment category.

rioGrandeStorages, sanJuanStorages, and sanJuanPassThruStorages are lists of storage slots on all accounts with the specified water type.

rioGrandeTransfersIn and rioGrandeTransersOut are lists of Transfer slots on all accounts with the RioGrande water type.

To carry out Carry out the rioGrande Storage iterative loop until the Rio Grande storage converges, you must do the following in the order indicated:

This is the loss assuming only Rio Grande water in the reservoir, no San Juan water. These results are set in the Hypothetical Condition table series slot. Losses here are positive values.

The total Gain/Loss allocated to San Juan storage accounts is the difference between the Present Condition Loss and the Hypothetical Condition Loss. A positive value for each of these components represents a loss. In the Gain Loss slot on each account, a positive value represents a gain, and a negative value represents a loss. Thus the negative of the difference is taken before distributing the loss to the Gain Loss slot. The loss is distributed based on the contributing percentage of the total storage at the end of the previous timestep. If the total San Juan storage at the end of the previous timestep was zero, then the Gain Loss is zero for all accounts.

for all San Juan accounts

This allows the San Juan accounts to solve for Storage. The sum of all San Juan storages can then be used to calculate the total Rio Grande storage.

The AccumPermSediment is calculated by the selected method in the Sediment Transport category, and the value is set in the Est Sed Deposition table series slot.

If totalRioGrandeStorage is zero, then prevTotalRioGrandeStorage is used in the denominator. If both are zero, then epsilon is zero. The iterative loop repeats until the absolute value of epsilon is less than the specified tolerance in the Convergence Percentage slot or the maximum number of iterations is reached.

A positive value for Physical Model Net Loss represents a loss.

A negative value for totalSanJuanGainLoss represents a loss.

A positive value for totalRioGrandeLossTemp represents a loss.

If there is a RioGrandeConservation account, then the Rio Grande Losses are divided proportionally between the RioGrande account and the RioGrandeConservation account (details below). If there is no RioGrandeConservation account, then all RioGrandeConservation values in the steps below are zero.

If the reservoir is Locked In (indicated by a value of 1 in the Locked In slot), a percentage of the Rio Grande loss is allocated to the Carryover Content, proportional to the percent contribution to total Rio Grande storage. If the reservoir is not locked in, all Carryover values are zero.

All other Rio Grande losses and storage go to the Incidental pool.

If totalRioGrandeLossTemp is negative, representing a gain, then the gain is either divided proportionally between the Conservation and Incidental pools (if the Conservation Gain Switch is “On”), or the entire gain goes to the Incidental Pool.

For the remaining cases, totalRioGrandeLossTemp is positive (a loss). The temporary loss can be adjusted based on which pools have water.

If it is the first timestep locked in, then Carryover gets all of the storage and the Incidental pool gets all of the loss.

Each table represents a table series slot. The row names represent the column headers in the table series slots.

The Elephant Butte and El Vado Gain Loss method carries out the following steps.

For a 1 Month timestep, this can be done based on the Precipitation Volume for the month, which will have been set in simulation. The Precipitation Volume calculation will already account for Ice Coverage if applicable. For a 1 Day timestep, Effective Precipitation must be calculated using the cumulative sum of Precipitation Rate from the beginning of the month to the current day, and Ice Coverage is included explicitly. At a 1 Month timestep the average surface area is used, whereas the current (end of timestep) surface area is used for a 1 Day timestep.

For all following calculations, Area values for a 1 Day timestep are current (end of timestep) areas. For a 1 Month timestep, Area values are averages of the end of the previous timestep and end of the current timestep values, similarly for Ice Coverage. If Ice Coverage is not applicable based on the selected evaporation method, it is zero in the calculations below.

If the Surface Area is zero, then evapDepth and effecitvePrecipDepth are zero, and if Ice Coverage is one, then effectivePrecipDepth is zero.

Each of these values is positive for a loss. The PreRes areas are contained in the Control and PreRes Areas table slot. The results of these calculations are set in the PreReservoir Condition table series slot.

Each of these values is positive for a loss. The results of these calculations are set in the Present Condition table series slot.

The netInflowVolume will be negative if there is unidentified loss. If netInflowVolume is positive, then unidentified loss is zero. The Storage Adjustment from Elev Vol Table Change component is only included if the Time Varying Elevation Volume method is selected for the Sediment category.

unidentifiedLoss will be positive for a loss.

rioGrandeStorages, sanJuanStorages and sanJuanPassThruStorages are lists of storage slots on all accounts with the specified water type.

rioGrandeTransfersIn and rioGrandeTransersOut are lists of Transfer slots on all accounts with the RioGrande water type.

To carry out the RioGrande Storage iterative loop until the Rio Grande storage converges, you must do the following in the order indicated:

This is the loss assuming only Rio Grande water in the reservoir, no San Juan water. These results are set in the Hypothetical Condition table series slot. Losses here are positive values.

The total Gain/Loss allocated to San Juan storage accounts is the difference between the Present Condition Loss and the Hypothetical Condition Loss. A positive value for each of these components represents a loss. In the Gain Loss slot on each account, a positive value represents a gain, and a negative value represents a loss. Thus the negative of the difference is taken before distributing the loss to the Gain Loss slot. The loss is distributed based on the contributing percentage of the total storage at the end of the previous timestep. If the total San Juan storage at the end of the previous timestep was zero, then the Gain Loss is zero for all accounts.

for all San Juan accounts

This allows the San Juan accounts to solve for Storage. The sum of all San Juan storages can then be used to calculate the total Rio Grande storage.

If totalRioGrandeStorage is zero, then prevTotalRioGrandeStorage is used in the denominator. If both are zero, then epsilon is zero. The iterative loop repeats until the absolute value of epsilon is less than the specified tolerance in the Convergence Percentage slot or the maximum number of iterations (Max Iterations slot) is reached.

Calculate the total Rio Grande Gain (+):

The Storage Adjustment from Elev Vol Table Change is applicable only if the Time Varying Elevation Volume method is selected for the Sediment category. It is removed at this point in the calculation because all loss from the Elevation-Volume change will be allocated later to the RioGrande account.

For the Elephant Butte Gain Loss method, the remaining evaporation and precipitation are charged to all accounts with water type Rio Grande that had a positive previous storage. Any Rio Grande accounts with negative storage do not get any of the remaining evaporation and precipitation. Then any other losses due to seepage or reconciliation of the reservoir charged to the single RioGrande account, whether the previous storage was positive or negative.

The computations are as follows:

First compute the remaining evaporation and precipitation loss:

The evaporation/precipitation loss is distributed based on the contributing percentage of the total storage at the end of the previous timestep.

This will distribute the remaining evaporation and precipitation to the positive Rio Grande accounts. The RioGrande account’s RioGrande.GainLoss slot will either get a gain if positive previous storage or zero gain if negative previous. If all accounts with the RioGrande water type have zero or negative storage at the previous timestep, then all of the gain/loss goes to the RioGrande account.

Next, compute the remaining gain that includes seepage and any other gain necessary to reconcile the reservoir:

This remaining gain is then added to the Rio Grande account’s Gain Loss:

With this approach, the Elephant Butte.Storage = SanJuanStorages + RioGrande.Storage (whether this is positive or negative) + other RioGrande account storage only if positive (that is, positive credit accounts)

The positive gain (or negative loss) is distributed based on the contributing percentage of the total storage at the end of the previous timestep. The gain is only distributed to accounts with positive storage, where the negative previous storage is included in base value when computing the percentage. The negative RioGrande water is considered part of the reservoir reconciliation. If all accounts with the RioGrande water type have zero or negative storage at the previous timestep, then all of the gain/loss goes to the RioGrande account.

This value will be negative for a loss.

A positive value for Physical Model Net Loss represents a loss.

A negative value for totalSanJuanGainLoss represents a loss.

A positive value for totalRioGrandeLossTemp represents a loss.

The Elephant Butte and El Vado Gain Loss sets the following table series slots.

Each table represents a table series slot. The row names represent the column headers in the table series slots.

The Nambe Falls Gain Loss method carries out the following steps.

For a 1 Month timestep, this can be done based on the Precipitation Volume for the month, which will have been set in simulation. The Precipitation Volume calculation will already account for Ice Coverage if applicable. For a 1 Day timestep, Effective Precipitation must be calculated using the cumulative sum of Precipitation Rate from the beginning of the month to the current day, and Ice Coverage is included explicitly. At a 1 Month timestep the average surface area is used, whereas the current (end of timestep) surface area is used for a 1 Day timestep.

For all following calculations, Area values for a 1 Day timestep are current (end of timestep) areas. For a 1 Month timestep, Area values are averages of the end of the previous timestep and end of the current timestep values, similarly for Ice Coverage. If Ice Coverage is not applicable based on the selected evaporation method, it is zero in the calculations below.

If the Surface Area is zero, then evapDepth and effecitvePrecipDepth are zero, and if Ice Coverage is one, then effectivePrecipDepth is zero.

Each of these values is positive for a loss. The PreRes areas are contained in the Control and PreRes Areas table slot. The results of these calculations are set in the PreReservoir Condition table series slot.

Each of these values is positive for a loss. The results of these calculations are set in the Present Condition table series slot.

The netInflowVolume will be negative if there is unidentified loss. If netInflowVolume is positive, then unidentified loss is zero. The Storage Adjustment from Elev Vol Table Change component is only included if the Time Varying Elevation Volume method is selected for the Sediment category.

unidentifiedLoss will be positive for a loss.

The total Gain/Loss allocated to San Juan storage accounts is the difference between the Present Condition Loss and the PreReservoir Condition Loss. A positive value for each of these components represents a loss. In the Gain Loss slot on each account, a positive value represents a gain, and a negative value represents a loss. Thus the negative of the difference is taken before distributing the loss to the Gain Loss slot. The loss is distributed based on the contributing percentage of the total storage at the end of the previous timestep. If the total San Juan storage at the end of the previous timestep was zero, then the Gain Loss is zero for all accounts.

sanJuanStorages and sanJuanPassThruStorages are lists of storage slots on all accounts with the San Juan water type.

This will allow the San Juan accounts to solve for storage.

A positive value for Physical Model Net Loss represents a loss. A negative value for totalSanJuanLosses represents a loss.

If the reservoir elevation was increasing or if the reservoir was spilling, the change in storage is counted as risingChangeStorage otherwise it is droppingChangeStorage.

If the reservoir was not spilling at the end of the timestep but was spilling at the start, then these values need to be modified.

The Nambe Falls Gain/Loss method sets the following table series slots.

Each table represents a table series slot. The row names represent the column headers in the table series slots.

Physical Model Net Loss is positive for a loss. The account Gain Loss slot values are negative for a loss.

The Heron Gain Loss method sets the following table series slots.

For a 1 Day timestep, values are set in the following additional table series slots. These slots contain the monthly totals of their corresponding table series slots. The monthly sums are set at the last timestep for each month. All other cells display “NaN.” For a 1 Month timestep, no values are set in these slots.