Rivers
Dam pressure
With Dam pressure on, water pushes on everything that holds it back: dams, levees and floodgates, and walls too (palisades, walls, gatehouses, wall towers and hoardings all hold water). Each can hold so much water per block of thickness (a dam or a wall the least, a floodgate the most), and it holds more when it’s thicker (up to 4 blocks), when it stands on the ground, and when rock is close at its ends. Neighbouring blocks share the load, and flowing water pushes harder than still water.
Over its limit, a dam takes damage, faster the more it’s overloaded, and at 100% it gives way. Under its limit it mends slowly, but not while it’s under fire. The panel shows the water pressure as a share of its limit, and with the landscaping tools open dams are tinted green, yellow or red.
A battering ram’s swings and water mines weaken dams too.
A wall built across a river, or used to flood an enemy, is a dam: too much water behind it and it gives way like one.
Water mines
Main articles: Mine Workshop, Mine Slipway, Moored Mine, Mine Net and Net Winch
The Mine Workshop makes water mines, and the Mine Slipway launches them into the current. They drift, arm after a short while, and go off when they hit something, or at the bottom of a waterfall. Moored mines sit on open water and go off when a boat or a drifting mine comes close. Mine nets catch drifting mines, and a Net Winch hauls the catch in for you to use.
A blast (1.6 tiles around):
- destroys small buildings (4 tiles or less) and damages bigger ones and walls;
- weakens dams;
- hurts beavers;
- sets off armed moored mines nearby, which can chain.
Roads aren’t hurt.
Fireships
Main article: Fireship Dock
The Fireship Dock launches a boat upstream, packed with explosives. It blows up on the first building or mine it hits, and sinks near a water source or at the map’s edge.