In this paper, we aim at a mid-term planning model for hydropower production based on multistage stochastic optimization. We decide about one production schedule for a horizon of one year from the point of view of a producer that owns pumped-storage hydropower plants. These consist of large, seasonal connected reservoirs. We consider stochastic inflows, stochastic electricity prices and stochastic loads. The produced electricity is sold at the spot market. In addition, we follow an indifference pricing approach for non-standard power contracts to determine the price at which the producer is willing to deliver electricity to individual consumers.