The Water Temperature Transaction Tool (W3T) is an easy-to-use, interactive model for quickly evaluating stream temperatures under a variety of scenarios. The tool allows users to define a simple river reach and change basic characteristics, such as surrounding shade, cross-section form, channel slope, and tributaries and diversions, to evaluate potential benefits of flow transactions as they relate to river temperature. In defining the river reach, tributaries and diversions may be placed anywhere along the reach length and can be moved, removed, or added to develop different scenarios for comparison. Users may interactively specify reach length, inflow, tributary flow, and diversion amount. Water temperature can be assigned within W3T from a list of records and assigned to each inflow. Unique shade scenarios can be developed within W3T and assigned to individual sections of a reach.
To evaluate potential management decisions and compare scenarios, a set of summary tables and graphs are included. These summaries include tables of input parameters and results and graphs of inflow versus outflow temperatures, longitudinal daily minimum, mean and maximum temperatures, and solar radiation resulting from scenario assumptions. W3T includes the ability to save a baseline scenario for comparisons. Outflow temperatures and solar radiation under baseline conditions may be graphically compared to results from current scenario conditions. Solar reductions (compared to theoretical maximum as well as versus a “pre” and “post” condition) are also reported (consistent with Shade-a-lator reporting). In addition, heat leaving the reach (kcal/day) is calculated and compared to baseline.