Quickstart user manual for Water Wheels

This is a short and concise illustrated list of hints and explanations I initially made for discord about water wheels, their common problems and usage tricks.

The problem of water going around

Using water wheels might be tricky due to imperfect water simulation.

Long story short - most reliable way is to block the river completely with wheels and levees so water has no other way except flowing through the wheels.

Here is a recipe for early game: combine dam and wheel in way dam directs flow through the wheel. Requires early unlock of levees.

Now for more details, if you wish.

First of all wheel power output depends on the flow strength. Look at the water surface and you can tell where it's faster. Placing wheel orthogonal to the stream or against the bank is initially a bad idea.

But even if you found a sweet straight spot with speedy water you may suddenly find that upon wheel completion it's output is not that high or it doesn't work at all. Problem is that wheel give a resistance the water flow and that can be buggy.
It could also work fine first but stop and start again if flow changes, for example with season change.

Solution is like I've stated above - pretty simple. Make water flow through the wheel by not giving it any other options. Either by placing wheel, or blocking with levees. Dams are unlikely to work reliably.

On Plains (recommended) map river flow strength can be managed by just three dams, so comes the recommended starting design. It combines a dam you want early and spot for a wheel. This give you a pretty good start.

Further consider you could use a couple of wheels in a row and a couple of levees on sides or between them - it doesn't matter.

Placing a row of wheels across a river

Placing several wheels in a row (on a same axle) across single stream doesn't really improve power output, see the attached images.

Power production depends on flow strength, if you add more wheels it's just re-distributes between wheels (if it has no other place to go).
Just use number of wheels to have a gap wide enough to fit all the flow and not cause a flooding.

You can see each row produces roughly same amount power in total, there are fluctuations, 5 wheel give even slightly less

Don't use dams to channel the flow

They will likely pass flow through them as well, compare to case from earlier section.

Only surface of water counts

If you put wheels on levees instead of platforms it won't generally affect power generation or flow strength on the surface, there is no "depth flow". That's how water is implemented in the game on current version (0.5)

Wheel can work submerged up to around half of it's height

But deeper it will get flooded and stop.
As discord comrades report it actually stops when block with axle is fully flooded, so it's actually 2/3 and 3/5 flooded for normal and large wheels respectively.

Falling water doesn't work on wheels

This won't work regrettably, wheel need to be submerged in a flowing water. Maybe one day...

Large wheel placement from a side

Unlike Folktails wheels and compact wheels, large wheel is not placed on a frame resting on bottom surface but is suspended on a side support.

Support needs to be at least 2 tiles higher then location where the wheel itself goes. If you have 1 tile deep river, place it higher, e.g. on a platform, wheel does not have to go 2 deep in the water.
It still has power connectors on both sides.

Large wheel support is not solid

Many wish it was. But you build a bridge over it, but it has to 2 tiles high.

Large water is more efficient for it's footprint

Even if you count support, here I simply place them if they were 3x5
Taken from update 4, but still generally applies.

Power calculation per cm\s is average of flow

Folktails wheel says it outputs 135 HP / cm/s in description (game version 0.5) but it's actually an average per tile of wheel width.
Meaning real calculation would be:

power = (total_cms / wheel_width) * power_per_cms
# For example case from pictures attached:
power = (2 / 2) * 135 = 135 # (138 is normal fluctuation)

In other words for 2-tile wide wheel you need total flow through it of 2 cm/s to see nominal output. Perhaps images are easier to understand.

For IronT small wheel of single width number is straight, 60 HP for 1 cm/s total flow.