This publication provides code, WaterSupplyTippingPoints.R, to calculate tipping points in water supply by using a time series of deficit data. The code uses data files that are produced from an agent-based model that simulates water supply dynamics. The code uses deficit data to calculate a water supply performance metric, Sustainability Index, and implements a decision tree change point detection method detects change points. The code implements a tipping point rule that is applied to select a change point as a tipping point. Data files of deficits that are used as input are described and published at https://zenodo.org/record/3971213. The code can be executed for four management scenarios and 16 shifting climate scenarios. Management Strategy 1 is no management. Management Strategy 2 is retrofitting. Management Strategy 3 is retrofitting with reactive drought restrictions. Management Strategy 4 is retrofitting with proactive drought restrictions. The 16 shifting climate scenarios correspond to shifting factors equal to 0.25 - 1.0, increasing in 0.05 increments. For each of the 64 modeling scenarios (16 climate settings X 4 management strategies), 100 simulations were run to capture stochasticity. The output from the code are provided in a set of .csv files, attached here. Data files (TippingPoints-mgmt1.csv, TippingPoints-mgmt2.csv, TippingPoints-mgmt3.csv, TippingPoints-mgmt4.csv) list the 100 tipping points that were identified for each shifting factor and each management strategy. Columns (V1, V2, ... V100) are 100 unique and randomized simulations for each modeling scenario. Rows correspond to shifting factors, where Row 1 is shifting factor 0.25, and Row 16 is shifting factor 1.00.