Patch from Geoff Podger floodplain storage

Hi Davo,

Scott found a nasty bug in the Macquarie. Basically his floodplain storage worked okay until 1951 and then it turned off.

The reason behind this was due to the storage volume going negative. The storage was going negative due to a rounding error on scaled et and seepage loss. This caused a group misclose error because the groups had a max(0.0, while the CSV did not. It corrected the group misclose (not really necessary as it was already 0) but did not set the csv to 0. This then left a permanent misclose and it kept setting the storage volume to zero. I have fixed it in two locations one where the vol is set. I make sure it is zero and also at the misclose adjustment.

It is a bit of a random error but I do wonder in the 10,000 year runs if this happened. If it does the storage will remain at zero for the rest of the run and probably not get discovered. It can be checked by looking at the storage volume in the last few years and if it is not flatlining at 1 then it is okay.

Regards

Geoff