HEC-RTS by default automatically sets the debug level for the DSS log file at three (3). From the Options dialog, click the Debug tab (Figure 1),  you can set the debug level to value between 1 and 15, in the DSS Debug Level box (Figure 1). Keep in mind that increasing this value can generate very large log files, since this value is setting how much DSS debug information is written to the CWMS log file.

Figure 1 Options Dialog - Debug Tab