Water resources management models aims to utilize the availability of water resources so as to meet the demand of many users as possible as can. In this paper, a two - stage stochastic programming for optimizing water resources management problem is introduced in pentagonal fuzzy neutrosophic environment. The problem is considered by incorporating probabilistic seasonal flow and pentagonal fuzzy neutrosophic numbers for all water - allocation target, net benefit, net benefit reduction, and seasonal flow. Based on the score function, the problem under consideration becomes deterministic one and with any linear programming techniques, we obtain the solution. For illustration, an example is given for the sake of the paper.