Editing v0.34:Floodgate

{{quality|Exceptional|12:39, 19 September 2010 (UTC)}}{{av}}
A '''floodgate''' is a gate which allows the control of the flow of liquids such as [[water]] or [[magma]]. They are operated by [[mechanism]]s such as [[lever]]s or [[pressure plate]]s which open and close them. When closed they behave like walls, but allow liquids, objects, and [[creatures]] to pass over them when opened.

They can be manufactured from [[stone]] (at a [[mason's workshop]]), [[wood]] (at a [[carpenter's workshop]]), [[metal]] (at a [[metalsmith's forge]]), or [[glass]] (at a [[glass furnace]]). Once manufactured, they are built in the desired location using the keys {{k|b}}, {{k|x}}.

In most situations, simply using a [[door]] or raising [[bridge]] can be used in place of a floodgate, and provides a number of [[bridge#Floodgates|significant advantages]].

[[image:Colossus_in_Arena.png|thumb|right| <br />
'''Colossus in Arena'''<br /> This image depicts some orthodox and unorthodox uses of floodgates to control the mixing of creatures and liquids in this arena. The gates, shown in-game as X, act as liquid stoppers and [[jail]] doors.]]

==Uses==

Floodgates are used to control the flow of liquid. Because of the [[water|usefulness]] of certain liquids and the [[magma|danger]] posed by others, floodgates have a wide range of applications in any dwarven settlement.

They are instrumental in controlled [[irrigation]] for [[farm]]ing, or controlled [[flood]]ing for [[Trap_design#Water_traps|drowning]] [[elf|annoying]] [[goblin|visitors]].

Floodgates also block the flow of liquid on the Z-axis as it is considered a wall when closed. This can be quite useful when built directly below a [[floor_grate| floor grate]] as this will allow you to quickly empty the liquid from the floor above without the danger of its [[goblin|precious content]] rummaging through your sewer system.

A [[pressure plate]] on a lower level connected to a floodgate between your main water supply and your other water controls can act as an automated safety valve to help prevent [[Pressure|massively flooding]] your lower fort. Set the pressure plate to activate (open the floodgate) when 0-1 water, which allows using the water supply.  When flooding starts, the pressure plate deactivates, attempting to close the floodgate. Beware of linking multiple controllers to this floodgate, as another controller may activate opening the floodgate before this pressure resets.

==Placement==

Floodgates are constructed [[orthogonal]]ly on a solid, '''''[[water depth|unflooded]]''''' floor in the 'closed' position (note that this means it is possible for careless dwarves to trap themselves on the wrong side of the gate). Adjacent walls are not necessary. A [[mechanic]] must then link up a [[lever]] or other triggering mechanism to the floodgate. This requires two [[mechanism]]s; the mechanic will haul one mechanism to the floodgate, work for a while, and then haul the other mechanism to the trigger to complete the task.

You can build a floodgate over empty space, e.g. controlling water in a vertical path. First build a floor ({{k|b}}, {{k|C}}, {{k|f}}), after it is complete mark it for removal ({{k|d}}, {{k|n}}) and immediately designate your floodgate ({{k|b}}, {{k|x}}).  You don't have to suspend either of these tasks to get both to complete.  You may want to remove the stone or block left by removing the floor or it may be washed down to lower levels, possibly clogging another floodgate that is built on a floor or [[door]].

==Activation==

Once the lever is pulled, with a [[Trigger#On.2FOff_states|delay]], the floodgate will open. When the lever is pulled again, the floodgate will close, after same delay. This will destroy (not displace) any liquid occupying the same tile as the floodgate. Objects on the floodgate's tile, however, cannot be destroyed this way - in fact, the floodgate will refuse to close. Any object, everything from [[sword]]s to [[sock]]s to [[stone]]s to scorpion [[corpse]]s, can jam the floodgate this way. Once the object is removed, however, the floodgate will grind shut by itself.

==Magma control==

Floodgates will resist magma when closed, just as a constructed [[wall]] would, but when opened will be destroyed if they are not made from [[magma-safe|magma-safe materials]]. The mechanisms used in the construction of the floodgate must also be magma-safe to prevent this.

==Bugs==

* Floodgates built on a constructed wall remain standing (and functional) even after that wall is removed, leading to an exploitable, free-floating building. {{Bug|0377}}

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