A simulation-based inexact rough-interval programming approach is proposed for agricultural irrigation management in a China’s rural region. The conjunctive use of multiple water sources is examined under a set of land-area, water-availability, environmental-standard, capital, and technical constraints. The formulated model presents capability in interpreting implication of various water-supply means on agricultural water-allocation plans, as well as handling highly-uncertain parameters existing in many real-world practices. A case study in the central-south China demonstrates the applicability of the proposed model. The modelling inputs of economy-related parameters are identified as conventional intervals based on the statistical data, while those of water availability are characterized as rough intervals by converting the predicted values from a distributed hydrological model. Scenarios of groundwater supplementation rates being 0, 20, 30 and 40 %, respectively are considered to generate optimal irrigation plans. Reasonable results are obtained, which are then used to analyze the impact of water-supplier variation on planning sustainable development strategies.