Optimizing green infrastructure placement under precipitation uncertainty

•Green Infrastructure (GI) practices are low cost, low regret strategies that can contribute to urban runoff management.•Stochastic programming models are used to determine the optimal placement of GI practices under precipitation uncertainties.•A novel scenario generation process is used to efficiently evaluate the impact of precipitation on the entire watershed system under various combinations of GI practice placement.•Optimal GI placement in an urban watershed of a mid-sized city in the US can contribute to up to 9.5% reduction in total expected runoff, given a limited budget of 25 million dollars.•Using a stochastic programming model with perturbed parameters reduces the computational times, without compromising the solution quality.•Accounting for sub-catchment-level runoff reduction considerations can increase resilience against precipitation uncertainty.