Does anybody know of any cheap or free software available for the plotting of inflow outflow hydrographs and hence storage volume? I am in the UK and used to use a simple dos based program called FLOOD2 which is very old and now sadly broken.
You could also copy the hydrograph data to Excel; you can use the program to calculate the volume of storage by integrating numerically the area between the two hydrograph curves, and you can plot the hydrographs as well.