The use of locks always implies a loss of water from upstream to downstream.  The loss is proportional to the dimensions of the lock. On many waterways this water loss can become critical during dry summers. So often the lock dimensions will be an equilibrium between capacity needed (to decrease navigation delays) and water lost. IMDC disposes of commercial and made to measure tools to design locks and has the know-how for proposing water saving measures when needed (double locks, pumping, water basins, ...)