Overview

The objective of this section is to verify and validate the HEC-ResSim operations feature: Overrides. This section only covers the Overrides Editor and does not include any testing on the Operational Support Interface (OSI) Editor. This is accomplished by creating a simple ResSim model with one Operation Set and one Alternative named OverrideBase and Override, respectively. To test each override option while retaining results, Simulations and trials were created for each test case for the same Alternative and Time Window. During model set up and testing, it was discovered that Capacity Overrides and Storage Overrides were not functioning properly. JIRA tickets were created to troubleshoot the issues. This document covers the successful testing of overrides for Reservoir Target Elevation, Reservoir Releases, and Diversions.

Model Setup

A simple ResSim model was set up to be used for all the simulations, consisting of a single stream and one reservoir. To properly test Overrides, the reservoir was developed to have one controlled outlet. Figure 1 displays the model schematic and the physical attributes of the reservoir. For all Operation Sets, the same Zones and rules were used.

Figure 1 - HEC-ResSim Overrides Model Schematic and Physical Properties


Reservoir Elevation Target Override

Model Setup

To test Overrides of Reservoir Target Elevation, a Simulation named Elevation_Target was created. Figure 2 displays the Override Editor before any overrides have been applied. For this test, the Override Alternative was run and then a trial was created. On the trial, any elevations that exceeded 70 ft were set to 70 ft.

Figure 2 - HEC-ResSim Override Editor - Reservoir Elevation Target


Results and Discussion

The results from trial with overrides was compared to the base and the operational plot can be seen in Figure 3. The green lines represent the base operations without overrides while the red lines represent the simulation that has elevation target overrides. The base model elevation increases to 71.5 ft and releases peak at 300 cfs while the override simulation has the elevation plateau at 70 ft and the releases increase to hold that elevation. In addition to reviewing the tabular outputs and the plots, an excel spreadsheet was created to check that mass balance was not violated. The excel spreadsheet, Overrides.xlsx (Elev_Target sheet), has been saved in the main model folder. With these results and the excel spreadsheet confirming that mass balance was not violated, this test has been verified.

Figure 3 - Operational Plot Comparison of Base with Elevation Target Override


Reservoir Release Override

Model Setup

To test Overrides of Reservoir Releases, a Simulation named Res_Release was created. Figure 4 displays the Override Editor before any overrides have been applied. For this test, the Override Alternative was run and then a trial was created. On the trial, all releases were set to 200 cfs.

Figure 4 - HEC-ResSim Override Editor - Reservoir Release


Results and Discussion

The results from trial with overrides was compared to the base and the operational plot can be seen in Figure 5. The green lines represent the base operations without overrides while the red lines represent the simulation that has reservoir release overrides. The base model elevation increases to 71.5 ft and releases peak at 300 cfs while the override simulation has constant release of 200 cfs and the elevation varies slightly from the base as the base flows varied between 100 to 300 cfs. In addition to reviewing the tabular outputs and the plots, an excel spreadsheet was created to check that mass balance was not violated. The excel spreadsheet, Overrides.xlsx (Release sheet), has been saved in the main model folder. With these results and the excel spreadsheet confirming that mass balance was not violated, this test has been verified.

Figure 5 - Operational Plot Comparison of Base with Reservoir Release Override


Diversion Override

Model Setup

To test Overrides of Reservoir Releases, a Simulation named Diversion was created. Figure 6 displays the Override Editor before any overrides have been applied. For this test, the Override Alternative was run and then a trial was created. On the trial, all releases were set to 100 cfs.

Figure 6 - HEC-ResSim Override Editor - Diversions


Results and Discussion

The results from trial with overrides was compared to the base and the diversion plot can be seen in Figure 7. The green lines represent the base operations without overrides while the red lines represent the simulation that has diversion overrides. The base model diversion release is set to 0 cfs while the override simulation has constant release of 100 cfs. In addition to reviewing the diversion plots and tables, the junction where the diversion occurs was reviewed. Figure 8 displays the flows that occur at the junction where the diversion is located. The override simulation (red) is 100 cfs less than the base model (green). With these results and the excel spreadsheet confirming that mass balance was not violated, this test has been verified.

Figure 7 - Operational Plot Comparison of Base with Diversion Override


Figure 8 - Plot Comparison at Diversion Junction of Base with Diversion Override