This tool is an aid for the pre-dimensioning of a fish ladder: it allows to calculate the missing value of the four quantities:

• the fall between the basins ($$\Delta H$$) in m;
• the flow rate ($$Q$$) in m3/s;
• the volume of the basins ($$V$$) in m3;
• the power density ($$P_v$$) in W/m3.

The formula for calculating the power dissipation is then:

$P_v = \frac{\rho \mathrm{g} Q \Delta H}{V}$

with:

• $$\rho$$: the density of water;
• $$\mathrm{g}$$: the acceleration of the Earth's gravity = 9.81 m.s-2