skip to main content
Objects and Methods : Control Point : User Methods : Instream Flow Reference Level
Instream Flow Reference Level
This category is used in conjunction with water accounting, specifically for water rights allocation, to establish a reference level from which an instream flow account on this object can base its water allocation requests.
The selected method is executed at the beginning of each timestep.
* None
This default method for the category means no reference level is to be computed.
* Reservoir Storages Lookup
This method executes one timestep each year identified by the Start of Reference Year slot. At that timestep, this method sums the storages at the previous timestep from each of the Reference Reservoirs. This storage is then looked up in the Reference Level Storage Table to determine the Reference Level. The Reference Level is used by the instream flow accounts on the object to determine the account’s Initial Request.
Slots Specific to This Method
 Reference Reservoirs
Type: ListSlot
Units: NONE
Description: Contains a list of reservoirs whose storages (at the previous timestep) will be summed.
Information: This slot is used by instream flow accounts on the object for water rights allocation. Its value is an input to the calculation of Initial Requests for allocation of water.
I/O: Required input
 Reference Level Storage Table
Type: TableSlot
Description: Maps volumes (sum of storages) to a reference level. Contains two columns, Sum of Storages and Reference Level. The user may add any number of rows, but at least one row must be present and populated.
Information: The sum of storages is looked up in the first column and the corresponding value in the second column is put into the Reference Level slot. No interpolation is done. If the sum falls between two values in the first column, the row chosen is the row with the largest first-column value that is less than the sum.
I/O: Required input
 Reference Level
Type: Series Slot with optional 1 Year timestep
Units: NONE
Description: The resulting reference level is placed here. This slot can be set to an 1 Year timestep slot; its value is computed once per annum, on the timestep identified by the Start of Reference Year slot. Because 1 Year timestep slots in RiverWare are given the December 31 date, the date of the timesteps will not match the Start of Reference Year (unless you set the start of the year to December 31!). If it is not a 1 Year timestep slot and the slot’s timestep matches the run’s timestep, the value is computed each timestep in the run.
Information: This slot is used by the instream flow accounts on this object. The value in this slot is used by a method that calculates the account’s Initial Request slot. On timesteps before the Start of Reference Year, the account method uses the previous year’s Reference Level, so you must populate this slot with an initial value if the Start of Reference Year does not coincide with the first timestep of the run.
I/O: Output
 Start of Reference Year
Type: TableSlot
Units: None
Description: Identifies month and day of timestep that is the start of the reference year; the timestep on which a new Reference Level will be computed.
Information: Contains two columns: “Month” and “Day”. Only the first row is used. See the information for the Reference Level slot, above for more information.
Note: The reference year cannot start on February in a model with a 1 Month timestep.
I/O: Required input
Revised: 08/02/2021