Reliability Improved Stochastic Dynamic Programming for Reservoir Operation Optimization Mohsen Saadat 1 & Keyvan Asghari 1 Received: 19 November 2015 /Accepted: 23 February 2017 / Published online: 28 February 2017 # Springer Science+Business Media Dordrecht 2017 Abstract Stochastic Dynamic Programming (SDP) is widely used in reservoir operation problems. Besides its advantages, a few drawbacks have leaded many studies to improve its structure. Handling the infeasible conditions and curse of dimensionality are two major challenges in this method. The main goal of this paper is proposing a new method to avoid infeasible conditions and enhance the solution efficiency with new discretization procedure. For this purpose, an optimization module is incorporated into regular SDP structure, so that, near optimal values of state variables are determined based on the available constraints. The new method (RISDP) employs reliability concept to maximize the reservoir releases to satisfy the downstream demands. Applying the proposed technique improves the reservoir operating policies compared to regular SDP policies with the same assumptions of discretization. Simulation of reservoir operation in a real case study indicates about 15% improvement in objective function value and elimination of infeasible conditions by using RISDP operating policies. Keywords SDP . RISDP . Optimization . Reservoir operation . Reservoir simulation 1 Introduction Reservoir operation management problems and different solution methods have thoroughly reviewed and discussed by many researchers such as (Wurbs 1993; Labadie 2004). Major issues related to reservoir operation as planning for the best practices are hydroelectric generation, irrigation demands, flood control scenarios, ecological impacts, etc. (Tran et al. 2016). For employing a realistic methodology such as simulation and optimization techniques, one needs to consider uncertainty conditions (Tsakiris and Spiliotis 2004) and stochastic variables like unregulated inflows. Water Resour Manage (2017) 31:1795–1807 DOI 10.1007/s11269-017-1612-y * Keyvan Asghari kasghari@cc.iut.ac.ir 1 Department of Civil Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran