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II.5.5 - DAM Button

Parameters that can be altered at each dam include transportation rules, spill equations, spill schedules, nitrogen supersaturation generated from spill, delay parameters, delay equations, powerhouse schedule, powerhouse priority, powerhouse threshold, diel passage distribution, mortality in different routes through a dam, fge, and dam survival. These elements can be applied to specific dams and in some instances to specific species.
Fig. 33 Dam menu

Transport: Transportation of Fish

Fish can be transported from any transport point (dam) to any river segment downstream using the transport menu. Rules of transportation are made to conform to the regulations according to the Fish Passage Plan for 19911. The Transport window is illustrated in Fig. 34.

Fig. 34 Transportation Tool
Transport Mort Equation: relating transport mortality to flow

This tool allows the user to specify a relationship between water particle travel time (WPTT) and transport survival, on the assumption that changes in flow affect how well fish survive transportation. For details of how to determine WPTT using CRiSP1.5, see the Water Travel Time: Residence Time in the River section II.5.3.

The tool is designed as an equation window, and is shown below in Fig. 35. Right-click on the two arrows at the top to select a dam and stock, respectively. Then adjust the four sliders at the bottom of the panel to achieve the form you desire. The first slider, tt1, sets the shorter of two WPTT values, and the second slider, m1+, determines the increase over the base mortality level that you want to associate with WPTT values of tt1 or shorter. Similarly, tt2 sets the longer of the two WPTT values, and m2+ associates an increase in mortality for transport where WPTT values are tt2 or longer. Between tt1 and tt2, CRiSP interpolates in a linear fashion. Note: if you DO choose to use this model you must click the "activate/save displayed equation" button to make it take effect. Also note that the WPTT values used in the model are determined by the settings in the Water Travel Time tool under the Reservoir menu: the relevant dates and the segment of the river in question are both drawn from the values used in that tool, so make sure you are using the values you want.

Fig. 35 Flow-dependent transport mortality tool.

Spill Efficiency: Efficiency of Passing Fish with Spill

This window sets parameters describing efficiency of passing fish with spill water at dams. It is set for each dam on a species-specific basis. The Spill Efficiency window has the following controls:

Fig. 36 Spill efficiency equation

Remember, if you change the equation you must click on the "activate/save displayed equation" button to make that equation active.

Spill Schedule: Spill at Dams

Spill refers to water that flows over the top of the dam. CRiSP.1 considers three types of spill.

The Scenario Mode considers Planned Spill and Forced Spill only. In the Monte Carlo Mode, Overgeneration Spill is obtained from the flow archive file, and Planned Spill can be obtained from the flow archive file or set with the Spill Schedule Tool. This choice is made with the Monte Carlo Tool. We recommend that spill be set with the Planned Spill Tool when making Monte Carlo runs.

Planned Fish Spill

Planned Fish Spill variables (in agreement with the 1991 Fish Passage Plan) are set with the Spill Schedule Tool as follows:

The relationship between these variables is illustrated in Fig. 37. Planned Spill Days allocate a certain fraction of the river flow to be spilled during specified blocks of days as given in the water budget. Different fractions can be set for different blocks of days. Fish Spill Days, however, indicate the actual days that spill will occur. The Fish Spill Hours specify blocks of time in each Fish Spill Day when spill occurs.
Fig. 37 Schematic of possible Planned Spill variables

The schedule window to set the Planned Spill is illustrated in Fig. 38. The Spill Tool window has the controls described below.

Note that in the example above, the second spill period demands 70% of total river flow, but only allocates 12 hours per day to spill it in. This will produce a warning message from CRiSP, since the model will be unable to achieve the 70% spill requirement by spilling only 50% of the time. Users should be careful to make their spill requests consistent with realistic dam operations.

Overgeneration Spill

This type of spill is established from Flow Archive files and is defined over periods of either two weeks or one month. The following scheme is used to allocate this spill in three hour periods.

Forced Spill

Forced Spill results if the river flow exceeds the total of the hydraulic capacity of the dam plus the Planned and Overgeneration Spills.

Spill Cap: Maximum Allowable Spill

This window provides sliders for each dam specified in the river, allowing the user to set a maximum flow which can be passed over the spillway for each dam. By default, the value used is 65 kcfs at Snake River projects and 235 kcfs at all other projects. Note that this only applies to planned spill; if forced spill requires exceeding the spill cap, the cap is ignored.

Nsat Equation: Nitrogen Supersaturation

This window defines the production of supersaturation due to spilling at dams. The relationship between spill in kcfs and percent nitrogen above 100% saturation in the water is illustrated in the equation window. Supersaturation can be developed by four separate submodels which can be selected in the equation window.

Fig. 39 Nitrogen supersaturation equation window

The following controls are available in the window:

In general, these parameters have been calibrated to existing data sets and we do not recommend that users alter these values.

Delay Parameters, Scalar & Equation: Delay at Dams

This is a submodel that delays fish at a dam depending on the species, time of day, season, and flow relative to hydraulic capacity. The effect of this submodel is that fish passage is delayed during daylight hours and during low-flow conditions. If the delay is sufficiently large fish may spend several days in front of a dam. The delay is expressed in terms of a passage probability, not in terms of observed passage.

The delay submodel is based on the premise that fish mill in the forebay of the dam and their rate of passage depends on how close they are to the dam. Proximity to the dam is determined by forebay depth, light levels, and behavioral parameters. These are set with the delay parameters and delay scalar windows chosen from the DAM menu and demonstrated in the delay equation window as a function of other model controlled variables.

The delay parameters (Fig. 40) are obtained by fitting the model to passage data and are not directly measured:

The probability of passage depends on the above model parameters and these model-calculated parameters: The resulting delay experienced by fish can be scaled by a linear amount using the sliders in the delay scalar window. The default value for delay scalars at each dam is 1.0, meaning there is no change in the calculated delay. Higher values increase delay, lower values decrease delay.

The passage probability in two hour intervals can be viewed with the passage delay window (Fig. 41).

Fig. 41 Dam Passage Delay as a function of hour of day

Powerhouse Capacity

Dams differ in their design, and different dams can accommodate differing amounts of flow through their powerhouse(s) before being forced to spill excess flow. This control allows the user to dictate how much flow each dam can put through its powerhouse(s) before being forced to spill the remaining flow. This control panel is shown below in Fig. 42.

Fig. 42 Powerhouse Capacity (kcfs) control window.

Powerhouse Schedules

Dams with two powerhouses can operate on a schedule to optimize survival during the fish passage season. The strategy is to operate the highest priority powerhouse up to its hydraulic capacity, then spill water up to another level called the spill threshold. Above this threshold, the second powerhouse is used. If the hydraulic capacity of the second powerhouse is exceeded, extra flow is spilled.

The powerhouse schedule sets the days and hours in which any powerhouse is used (Fig. 43). For times when the second powerhouse is not scheduled, the spill threshold is not applied and all flow exceeding the hydraulic capacity of the first powerhouse is put into spill only.

Fig. 43 Powerhouse Schedule Tool
Powerhouse Priority
The Powerhouse Priority Tool sets which powerhouse is designated the first powerhouse. Select house 1 or house 2 for both Bonneville and Rock Island Dam.
Fig. 44 Powerhouse priority selection

Powerhouse Threshold

The powerhouse threshold determines the maximum amount of spill allowed (in kcfs) before the second powerhouse is used.

Tailrace Length: Tailrace Residence Time/Length

CRiSP.1 determines the residence time of fish in the tailrace in terms of the flow, the width of the dam, and a tailrace length. This time is used in calculating predation in the tailrace. The time is set by adjusting the tailrace length with a slider.

Tailrace length is set to conform to the region of high flows immediately below the dam. This region also contains elevated predator densities.

Fig. 45 Time of fish in tailrace after dam passage

Mortality: Mortality in Dam Passage

Fish mortality in the various passage routes is defined for each dam and species. The mean, minimum and maximum values are defined for:

The probability distribution of mortality for each passage route is defined by a piecewise linear distribution within the range identified by minimum and maximum values. The mean must lie within the central two quartiles of the distribution of possible values: if values are chosen that do not conform to this restriction, CRiSP will not run and will generate an error message specifying which dams have bad parameters.
Fig. 46 Input window for dam passage mortality
Note that transportation mortality can be altered using parameters available in the transport mortality equation window, detailed in the Transport Mort Equation: relating transport mortality to flow section II.5.5.

FGE: Fish Guidance Efficiency

Fish guidance efficiency of the bypass systems at dams is defined for day and night periods. One of two possible functional relationships can be specified.

In both relationships fge is specific to a given dam and species and its random variations occurs for each dam time interval (typically 2 hours).

The probability distribution of fge is defined by a piecewise linear distribution within the range identified by the minimum and maximum values. The mean value must lie within the central two quartiles of the distribution. The slider for setting the probability distribution of fge is illustrated in (Fig. 47).

Fig. 47 Fge window

Constant FGE

The constant fge condition is selected by clicking off the age dependent fge in the Runtime Settings box under the RUN button (this is the default condition). Day and Night Fge then vary randomly on each dam time interval according to a fixed probability distributions, i.e. the distribution has no seasonal trend.

Time varying FGE

Time varying fge is selected by clicking on the age dependent fge in the Runtime Settings box under the RUN button. In this conditions day and night fge change randomly at each dam time interval according to probability distributions that change with fish age and reservoir elevation (Fig. 48).

Initial fge probability distribution is set by the fge sliders illustrated in Fig. 47. Variations in fge from this condition depends on Julian day, the day since the onset of smoltification, which is set in the release window, and reservoir elevation for each day, which is set with the elevation input window. The combinations of these factors is illustrated for in the Night Fge Equation (Fig. 48). A similar distribution occurs for Day Fge. the difference being determined by the sliders describing the probability distribution. In the illustration mean fge is depicted as a solid line and dotted lines illustrate minimum and maximum values. Fge is plotted against fish age relative to the onset of smoltification. To coordinate effects of age dependent behavioral factors in fge and the seasonal dependent reservoir level factor the user must select the Julian day of the onset of smoltification. Fge submodel parameters are as follows:

Dam Survival: Survival Probability at Dam

This window illustrates the probability distribution of dam survival as generated with the current setting of dam parameters (Fig. 49). The window provides a quick illustration of how the variety of dam submodels combine together to produce dam passage survival. In effect, this is a tutorial that runs independently of the Scenario or Monte Carlo modes. It calculates and displays survivals for 20 runs by left-clicking the run button in the window 1.

Fig. 49 Example of dam survival probabilities
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1 Corps of Engineers Projects, US Army Corps of Engineers North Pacific Division report CENPD-PE-WM March 1991.

2 Species to separate is the indicator species by which separation will cease if n% (80% by default) of the seasonal passage has occurred. Separation refers to those fish which will be separated and therefore not transported. All species are separated with likelihood defined by separation probability.

3 Note: Care must be taken to distinguish between the displayed day-averaged spill percentage (shown in the spill Julian day display windows) and the percentage of instantaneous flow that is to be spilled during spill hours (set in the spill schedule window). The latter is specified in the operational plans and in the 1989 Spill Agreement.

4 The separation of planned spill days and fish spill days is an arbitrary convention that arose out of the 1989 Spill Agreements. In practice the spill fraction should be indicated in the fish spill days and planned spill days should be illuminated. But this is not the way the agreement was written.

Columbia River Salmon Passage Model CRiSP.1.5 User Manual
Copyright © 1996, Columbia Basin Research. All rights reserved.

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