Gilles,

Regarding your first problem, the program checks for an exact equality between THISTO and TSTEP. This could be the problem (we should build in some slight tolerance for round-off errors.) The value of TSTEP is input in hours (as pointed out by Ron). Try inputting your time step values in units of hours, on line B3. This may give the same round-off for both numbers when they are converted to seconds in the program. And be sure to enter exactly the same hourly value for 5 minutes. That is, 5 minutes = 1/12 hour = 0.0833 hr. Don't use 0.083 on one line and 0.0833 on another line. In fact, use 0.0833333 on both lines to maximize the precision.

The RUNOFF.DOC file contains a working example along with the only documentation for this routine, unless CDM has something tucked away somewhere.

Regarding the H5 lines, yes, you need to insert H5 lines for any subcatchment for which you want to use this option. The computed l/I hydrograph enters the inlet defined by NGTO on the corresponding H1 line. The H1 and H5 lines are entered as pairs; don't enter all the H1 lines followed by all the H5 lines.

Only one H5 line can be entered for any one H1 line. You include an H5 line for any subcatchment that you desire (only one). You do not have to include an H5 line unless you want to. The limit on the number of H5 lines is the number of H1 lines.

Let us know if any of this helps.
Wayne