Information: If the Tailwater Base Value is non-zero, the Tailwater Table gives values of incremental increase in Tailwater Elevation over the Base value. If the Tailwater Base Value is zero, the table simply gives the Tailwater Elevation values. The Tailwater Table should have increasing values of outflow. Tailwater Elevation is required to be a convex function of outflow. The preferred order of approximation is substitution, piece-wise, two-point line, tangent. See Object / Simulation documentation for details.

Information: The Tailwater Table Lookup LP Param table values for outflow are used as approximation points indexing the Tailwater Table to determine tempTWLookupValue from the Tailwater Elevation column.

Information: Data must be entered into the table in increasing blocks of the same Outflow value for the three-dimensional table interpolation to work correctly. For every block of same Outflows in column 1, Downstream Stages should be listed in increasing order in column 2, and the corresponding Tailwater Elevations in column 3. Tailwater elevation is required to be a concave function of Outflow. The preferred order of approximation is substitution, piece-wise, two-point line, tangent. Internally, the Stage Flow Tailwater Table is rearranged to use the Stage as the primary index (column) with outflow as the secondary index (column). This rearranged table may be labeled as “Convolved Stage Flow Tailwater Table” in output messaging. Also, because of this rearrangement, it is desirable to repeat stage values for each outflow.

Information: This table is used for linearization. The best Tailwater Base Value point to choose for tangent approximation would be an outflow equal to the expected value of outflow during the run; for the line approximation, the minimum and maximum values expected during the run; for piecewise approximation, the minimum and maximum values expected during the run plus additional intermediate values to more closely fit the tailwater curve.

Information: Although this is part of the Stage Flow Lookup Table method (and its corresponding Opt method), this slot does not influence optimization. See Object / Simulation documentation for details.

Information: If the Power Surface Approximation method is selected, then there are additional restrictions on the coefficients that can be specified. With the Power Surface Approximation, having terms for Outflow[t-1], Tailwater BaseVal[t] and Tailwater[t-1] are not allowed.