So, lets just get a few baselines down. First off, I'm using ZM5's 64 modpack with all addons, have DFhack helping me out with some managing, and I haven't played Fortress mode for a few years, on top of that never getting too far into it, hardly ever really smelting my first metals and failing catastrophically at the military system.
I've chosen a gnome civilization (accidentally haha) and embarked in a place with two rivers, one up high heading off map almost immediately and one down low several z-levels, now, instead of doing the 'obvious' thing to connect the two more directly with channels, I've decided I'd reroute the upper river into my gnomish fort. Now, let me explain more in detail, I've gotten plans to make a large 'pit' as a water storage area, which the water will flow into (With a waterfall, so once I get the well up I'll get that nice mood bonus) after I finish digging the new underground river. I have to ask, has anyone ever done this? I know I'm doing this practically purposelessly now, after discovering the first cavern beneath my fort is filled with water. I'm entertaining that maybe forgotten beasts will make me wanna close that path off and therefore the only water able to get from inside the fort will be this massive tank. Something that I'm wondering about is the difference between floodgates and drawbridges for this purpose, as floodgates require a lot more orders to setup by appearance. Before its asked, I've also already setup a failsafe so that my entire fort won't flood. To paint the picture a bit better, so far the tank only has 3 z-levels, the middle z-level will have a flow-pipe out into the bottom river, while where the actual fort's well to access the water supply (on level with the waterfall's edge) is two z levels above that, so only if I really fuck up will my fort flood.
So I guess what I'm asking is are floodgates better then drawbridges, how the heck do pumps work, and what can I do with a waterwheel taking advantage of this waterflow? As well as if anyone ever bothered with this? The initial idea for the project came up with my realization that water underground doesn't freeze, while surface water did, back before I dug into the water cavern.