Terrain Painting
0-9 Select depth level
LMB drag Paint terrain with selected depth
ALT + Mouse wheel Change selected depth
ALT + RMB Pipette tool (pick depth)
SHIFT + Mouse wheel Change brush size (1-8)
Pumps & Water
SHIFT + LMB Add outlet pump
SHIFT + RMB Add inlet pump
CTRL + LMB Flood current or topmost basin
CTRL + RMB Drain topmost basin