Water balance, leakage law and piezometry

Frequently, the existence of water losses derived from a reservoir is suspected, but the losses cannot be quantified because either no water is emerging downstream of the reservoir or the existing springs do not represent the total amount of the leak. The latter situation occurs when part of the water losses is incorporated into the groundwater flow of a local aquifer or emerges at the bottom of a second reservoir located downstream. The last case was observed in the Canelles reservoir, Spain, where most of the escaping water was emerging at the bottom of the Santana reservoir.