Editing v0.34:River

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There are five different kinds of surface rivers in Dwarf Fortress: major rivers, rivers, minor rivers, streams and brooks. For most purposes, all of these will simply be referred to as '''rivers''' and '''brooks'''. The only differences between the first four types are their appearance in the world map, their width, and possibly their rate of flow. Brooks, being the smallest type of surface river, have the unique property that they can be crossed safely without needing to [[swimming|swim]] or even get one's feet wet.

In hilly terrain, particularly with [[cliff]]s, [[waterfall]]s can be found.

== Rivers ==
In fortress or adventure mode, '''rivers''' can be seen as dark blue {{Tile|≈|1:7:0}} and {{Tile|~|1:7:0}} tiles stretching from one edge of the local map to another. Rivers come in a variety of sizes, from tiny '''brooks''' only three or four tiles wide to major rivers spanning as wide as 40 tiles. If flow amounts are turned off in [[d_init.txt]], river tiles will also be constantly blinking to indicate that the water has [[flow]]. Rivers are an effectively unlimited source of water, entering the map at the upstream end and leaving at the downstream end. 

To determine which end of a river is downstream, you can carefully look at the ends of the river using {{k|k}}. The end that has multiple tiles of less than 7/7 water is the downstream end. (This strategy doesn't always work on freshly-generated maps, as the river can still be completely full of water.) Flow amounts can be enabled in [[d_init.txt]], which eliminates the need to use {{k|k}} but also removes flow indicators. A dwarfier method would be to [[unfortunate accident|kill something]], gets its blood in the river, and observe the direction of its movement.

Dwarves will not swim across rivers in fortress mode regardless of their [[swimming]] skill, and unskilled dwarves that end up in a river (both in fortress and adventure mode) can quickly drown in the current. Dwarves will only seek dry routes across rivers, such as a [[bridge]], [[floor]], or tunnel.

== Brooks ==
[[Brook]]s are the smallest type of [[river]]. They have a unique property that allows [[creatures]] (including [[wagon]]s) to travel across them without [[swimming]], or even getting their feet wet. [[Water]] and other fluids can fall through the surface of a brook, and [[fisherdwarf|fisherdwarves]] can stand on the surface of a brook to fish.

A brook can easily be identified by the white and cyan {{Tile|≈|3:0:1}} and {{Tile|~|3:0:1}} tiles on the surface, and will be clearly labelled as a brook when viewed with {{k|k}}. Like rivers, brook tiles will be constantly blinking to indicate that they have [[flow]].

[[Water wheel]]s will not function if placed directly on a brook. In order for them to work, you must dig a [[channel]] through the surface of the brook, which removes the special surface tile. This allows water wheels to be placed and function normally. In all other respects, brooks function exactly like any other river.

== Rivers in the regional map ==
On the regional map, there are five different classifications of rivers, identified by their appearance and the text displayed at the right side of the screen when they are selected in the local map view (major rivers, rivers, minor rivers, streams and brooks). Brooks are not directly visible on the regional or world maps, but can still be seen in the local map and will also be indicated at the right if you select a tile containing a brook.

[[Image:Watersystems01.jpg|298px|thumb|Different sorts of rivers in action; note that the labeled Brook is actually a Stream]]

*'''Major rivers''' can be identified on the regional map by their double dark blue lines which easily distinguishes them from other types of rivers that only have single lines. Major rivers are the largest rivers, potentially exceeding 40 tiles in width. They usually have minor river tributaries and can often feed large [[lake]]s. The massive amount of flowing water found in a major river may have a negative effect on your [[FPS]].
*'''Rivers''' can be identified on the world map as dark blue and usually have tributaries of minor rivers. They can often be over 10 tiles wide.
*'''Minor rivers''' are medium blue and usually have streams as tributaries. They are usually between 7 and 10 tiles wide.
*'''Streams''' are displayed as light blue on the region map. They often converge with other streams and have some brooks as tributaries. They tend to be 4 to 6 tiles wide.
*'''Brooks''' are only visible in the local map (not on the world map). They are the smallest flowing body of [[water]] that can be found in the game, being only 3 to 4 tiles wide. Brooks are very common - almost every tile around a stream or larger river will have a brook running through it.

== Other Important Facts ==
*Rivers contain an unlimited amount of water and cannot be drained like muddy pools.  They can, however, be [[dam]]med if you can ''temporarily'' drain part of them to 1/7 or less for long enough to construct [[wall]]s or install [[floodgate]]s. Despite being an unlimited source of water, river source tiles will only refill up to the level of the river's source - it will not overflow if you dam it up. This video demonstrates one way to drain and dam a river: [http://mkv25.net/dfma/movie-196-draininganddammingamajorriver-i]. Another way to dam a river is to direct [[lava]] into it, producing [[obsidian]] in the squares where it encounters water.
*Even if dammed, a dry riverbed will refill when it [[weather|rains]], similar to a [[murky pool]].
*A dammed river will cease to produce additional water once all of its tiles reach 7/7, even if the dam is subsequently opened, until the water level near the river's source drops below 7/7.
*After a river has been drained, the tiles will still appear as "river" when viewed. These appear to have no effect, but can be removed by [[floor]]ing over them or [[mining]]. If a construction is built on a river tile and removed, [[soil|furrowed]] soil will appear. 
{{World|Biomes}}

{{Category|Map tiles}}