Sluice
The 
Sluice is a 
Landscaping 
building. They are one-way automatic valves for controlling the flow of 
Fluids, such as 
Water and 
Badwater.
Construction
Unlike 
Floodgates, Sluices are solid. 
Paths and other structures and Buildings can be placed on top of sluices. They can be used at the bottom or middle of a retaining wall in a reservoir.
Usage
Sluice menu.Sluices can be set to be open, closed, or automatically operated. The automation opens or closes the sluice depending on contamination levels and downstream water depth set by the player.
Sluices are set to "Auto" by default where these rules can be set to apply:
- Close above downstream depth: 0.00 - 1.00 (example, up to the top height of the sluice)
- Opens when downstream depth is below the set amount.
- Has intervals of 0.05 depth.
- Defaults to half of the maximum depth between the sluice and the immediately downstream block.
- Use: controlling the river depth in lower downstream areas, or regulating reservoir discharge. See #Reservoirs and #Waterfalls below.
- Close above contamination: 0 - 100%
- Closes when fluid contamination exceeds the set amount.
- Has intervals of 1%.
- Defaults to 5%. Reducing this can be risky, as a small amount of contamination can persist for some time unless the upstream water course is perfectly straight with a strong flow.
- Use: close the main water channel during
Badtides.
- Close below contamination: 0 - 100%
- Opens when fluid contamination exceeds the set amount.
- Has intervals of 1%.
- Set to 5% by default. Reducing this can be risky, as a small amount of contamination can persist for some time unless the upstream water course is perfectly straight with a strong flow.
- Use: open a diversion channel during Badtides.
When multiple conditions are specified, they initiate when any single condition evaluates to true." (OR)
The second and third conditions cannot be set simultaneously, as they are opposites.
Adjacent sluices are synchronized by default and can be toggled off, just like Floodgates. This synchronization only applies to horizontally adjacent sluices facing the same direction.
Uses
Badwater diversion system
When used in combination, sluices are very useful to redirect Badwater and ensuring that your Beavers and colony do not get contaminated during a Badtide.
To make a diversion system
- Place sluices on the channel for the clean water, and set them to "Close above contamination 1%" (or more, don't be above 20%)
- Either:
- Place sluices on the adjacent diversion channel for contaminated water, and set them to "Close below contamination 0%" (similar to the example in the above illustration); or
- place levees on the clean water sluices and set the entrance to the diversion channel a block higher than the sluices so that the contaminated water overflows to the diversion channel when the clean water sluices close.
Reservoirs
When water passes down from one height level to the next, you can control the depth of the water in the lower level. This is especially useful for reservoirs. The sluices at the bottom only permit water to pass when the downstream level is low, thereby reserving water for surviving 
Droughts and Badtides.
To do this:
- Set up a #Badwater diversion system as above, between the
Water Source and the reservoir to ensure only uncontaminated water is stored. - Construct the reservoir with at least one sluice in the bottom.
- Use the first setting on the sluice to set it to close at a downstream depth 0.75, for a single block high downstream. Higher settings risk temporary
Flooding caused by surging water when the sluice opens. - Place sufficient
Dams at the top of the reservoir and construct a spillway. Spillways usually discharge into the river served by the sluice, but they can also use the Badwater discharge.
Waterfalls
Most maps aren't flat, so rivers descend as they progress.
For simple river depth controls to avoid flooding, especially when you start amalgamating Water Sources, on the upper level:
- place Sluices on the edge of the drop, set to close at 0.75, for a single block high downstream; and
- place Dams adjacent to the upstream side of the Sluices to ensure the upstream maintains a minimum water level.
Gallery
A sluice can be used to selectively sort Goodwater and Badwater.
Caption2
History
Update 6: Sluices introduced.
