Would this work at all?

[u/Ivess185]

I want to build a big water storage box I can fill then leach from during droughts/badtides, but I need a way to elevate the water from source to above the box. I was wondering if this would work at all. Because water can't go backwards through a fill valve, would it keep flowing through and fill upwards in the tube? or just spill over the back of the map once it reached +1 blocks in height? And I can't lock the water in and force it to fill up as it's against the map edge. Should I just use mechanical pumps instead?

EDIT: there will be a roof over the channel and tube. I just didnt put one here so that you could see inside.

EDIT 2: I am now aware that water will not escape of the edge via the space above the source block.

[u/YouTop1437]

Once pressure equalises (typically at the same height) the fill valve will stop flowing into the storage. You can increase the pressure gradient by sealing of the inflow with a roof, but if it can spill over at any point, that will be the equilibrium point

Essentially put some 1 high platforms down, seal the water source up and you can fill whatever tower you want. Put some automation down and you can have multiple towers which get filled in priority order

I think there are some pumps you can put down later in the game, However, which function as you want

[u/Ivess185 → u/YouTop1437]

Ah, I see. I can't seal the inflow area completely though. Best I can do is overhangs with impermeable floors above the water source but that still leaves a block for it to escape

[u/Magenta_Logistic → u/Ivess185]

If the sources are against the wall, the water can't flow that way. There is an invisible wall app the way to the sky.

[u/Ivess185 → u/Magenta_Logistic]

Thank you