Plot follow-ups!
So! In the interest of giving people even more plot hooks, feel free to use this post to mention anything your characters have done for the community to help them get through the flood and its aftermath.
For example, the boarding house would have opened its unoccupied rooms to any and all who needed them. Harry (and any others who wanted to) would have rationed his remaining food stock but then given it out for free (probably every couple of days).