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Objects
Control Point Regulation Discharge
In the Regulation Discharge, Reservoir Current (or Future) Level Regulation method, a new slot, Level Regulation Parameter Minimum, was added. This slot provides a lower bound on the Level Regulation Parameter. Previously, the Level Regulation Parameter was limited to always be greater than or equal to the reservoir's top of conservation pool. If values are not specified in the new slot, then the reservoir's top of conservation pool is used. Existing models do not need to be modified to match previous results.
Conductance Computations
On the Distribution Canal, Groundwater Storage and Reach objects, methods were added to compute the compute the Conductance for head based flow. Following is a description of the new categories and methods on these three objects.
Distribution Canal
The Canal Conductance Specification category was added with two methods:
• Specify Conductance (default) - conductance is required scalar value.
• Compute Conductance - conductance is computed from hydraulic conductivity, canal seepage thickness, and seepage area. This method is executed from at beginning of run.
Groundwater Storage
The Groundwater Conductance Specification category was added with two methods:
• Specify Conductance (default) - conductance is required scalar value
• Compute Conductance - conductance is computed from hydraulic conductivity, length, width, thickness, and anisotropy ratio of the given and the linked objects. Essentially, the object computes the harmonic mean of the conductivity using geometry of the two adjacent objects. This method is executed from beginning of run.
Reach
The Reach Conductance Specification category was added with two methods:
• Specify Conductance (default) - conductance is required scalar value
• Compute Conductance - conductance is computed from hydraulic conductivity, riverbed thickness, and seepage area. This method is executed from beginning of run.
Reservoirs
Energy in Storage Methods
The following changes were made to the EIS category and methods:
• The category energyInStorageCalcCategory was renamed Energy in Storage.
• The method noEIS was renamed the None method.
• The method tableLookup was renamed EIS Table Lookup.
Old models will automatically update on load and you will be notified with a warning diagnostic.
In addition, a new method was added to the Energy in Storage category, EIS Table Lookup with Cons Pool. This method uses a table lookup of pool elevation to interpolate the energy in storage. Then it uses the pool elevation corresponding to the top of conservation pool to get the EIS at the top of the conservation pool.
Evaporation Rates
The Evap and Precip Rate Specification category was added to the reservoir objects to allow alternative methods for specifying evaporation and precipitation rates. This category is only available when the Input Evaporation method is selected in the Evaporation and Precipitation category.
There are three methods in this new category.
• None: Rates must be input or they default to zero.
• Monthly Rates: Rates are specified as monthly series.
• Periodic Rates: Rates are specified on periodic slots.
Please see section 16.1.17 of the Objects chapter of the RiverWare help for more information.
Flood Control Minimum Release
In the Operating Level Balancing method in the Flood Control Release Calculation category, a slot Flood Control Minimum Release was added. This slot can be set by rule logic (along with Outflow) to make a minimum release before the Operating Level Balancing flood control algorithm is executed. The flood control algorithm will then respect this minimum and include it in outflow. For more information, see Flood Control Minimum Release in USACE‑SWD Modeling Techniques.
Operating Level slots
The following slots were added to the reservoir and are associated with method in the Operating Levels category:
Conservation Pool method:
• Conservation Pool Storage
• Conservation Pool Full Storage
• Conservation Pool Storage Fraction
Conservation and Flood Pools method:
• Conservation Pool Storage
• Conservation Pool Full Storage
• Conservation Pool Storage Fraction
• Flood Pool Storage
• Flood Pool Full Storage
• Flood Pool Storage Fraction
Conditional Operating Levels category, Sum Inflows over Interval method:
• Operating Level Storage 2 Table
• Conservation Pool Storage Fraction 2
• Flood Pool Storage Fraction 2
The “Storage” slots provide the actual storage in that pool. The “Full Storage” provides the total or possible storage in that pool. The periodic “Fraction” slots represent the percentage of that pool's storage at each level (column) in the Operating Level Table
Single Value Seepage
Previously, the Single Value Seepage method set non-input Seepage to the scalar value in the dispatch method. In some cases this led to excessive dispatching. To fix this, the Single Seepage Value method now fills the Seepage slot with the scalar value at the beginning of run.
Note, you can still input Seepage or set it with a rule.
Slope Power Reservoir
3D Tables Allow NaNs
The following three dimensional tables now allow NaNs at the bottom of a block:
• Partition BW Table
• Profile Storage Table
• Profile Backwater Table
Max Outflow Computation
Previously, in certain circumstances, setting max outflow on slope power reservoirs failed to solve correctly due to a diverging solution. The max outflow computation was improved to identify this diverging solution and use the bisection method.
Further, diagnostics were added in the Dispatch Management SimObj category to show the pool elevation and outflow (in user units) for each iteration in the max outflow computation on slope power reservoirs.
Segment Storage
In the SlopeStorageCalc method, two new slots were added:
• Segment Storage - Agg Series slot to report the storage in each segment
• Segment Storage Adjustment - 3D table slot to adjust the segment storage based on backwater elevation and change in backwater elevation from previous timesteps.
These slots are added to the SlopeStorageCalc but are used/calculated in the Impulse Response and Weighting Coeffs method which do the slope storage calculations.
Revised: 01/11/2023