The goal of this paper is to assess the profitability of investment in hydropower (HP) under three water fee systems: No-fee; Fixed-fee system, which is based on theoretical power combined with annual hydrological conditions (current system); Semi-flexible or fixed and variable fee system, with 50% based on fixed system and 50 % based on fluctuating electricity prices; Profit-based imposition system, which is based on the profit made by companies.