Hi everyone. As you may have guessed already, I need some help with Water Reactors. Not with building you basic, bog standard reactors, I can do that fine. I've actually got eight double-reactors in my current fort and they do their job as intended. The trouble I'm having is with turning them on and off and the associated water loss. I've been building an above-ground arcology on and off since 31.25 came out. Its a sweet embark, perfectly flat with a volcano/volcanic sinkhole slap bang in the middle and all the sand, gold and marble I need. Perfect. The only downside is that the only water come from the caverns. I've got a pumpstack to bring this to the surface with its own mini powerplant at the bottom. This fills up my larger surface powerplant. Basically, I'm eighteen years into this fort and its time to start the serious obsidian casting. However, the main powerplant is going to have to be significantly improved if I'm going to have any chance of raising both magma and water 40 and 77 z-levels respectively. Since I'm going to tear the thing down and rebuild it, I may as well do it properly. What I'm looking for is advice/designs that will give me a powerplant that I can turn on and off at will and which has the lowest possible water loss. Having to run the cavern water stack every time I want power on the surface is just to much of a drag on both my fps and my sanity.
Here's what I've been thinking so far:
1. Having a series of classic double reactors with a floodgate in the input square. Boring and same-ey, and still prone to water loss when you shut it down. Seems the simplest and best solution, but there must be something better out there.
2. Making an artificial cavern river. My cavern lake is on a high plateau, if I make it secure and arrange for it to flow off the edge I should be able to get a hell of a lot of power from it. But I worry that it will be way more work in reality than in my head and I've never tried this before. Plus, I'll have to run a power line to the surface. Grrrr.
3. Something like a 10x10x2 room with a floor with a hole in it separating the two levels, water wheels on the top level and a dwarf operated pump to bring water from the bottom to the top. This one would of course be terrible for water loss, but by far the most controllable since I can just tell the dwarf to stop pumping.
Anyway, give me your ideas and thanks in advance.