I planned to make a canal lock using the EPIC mod called ugocraft
(www.modsforminecraft.com/add-smooth-sliding-and-rotating-functionality-with-the-ugocraft-mod-1-2-5/)
And world edit. Here is the finished design....

The water filling was done by stacking the water using single player commands and undoing it, then i bound the undo and redo keys to keys on my computer, then if i wanted to fill the water i would hit redo 3 times, if i want to empty it i would hit undo 3 times. Hope thats easy to understand!