Over the past several years there have been increasing calls for decision support tools in the area of climate, and acknowledgement that changing extremes add to an already challenging decision environment for water managers. Recurring droughts, floods, and concerns over extreme events in the future have created a strong interest among water managers in the Front Range of Colorado in how to plan for these extremes. Traditional methods of identifying alternatives for water supply management may not fully capture the range of existing preferred alternatives, meaning that utilities may miss some of the solutions that appropriately balance among tradeoffs. In this project, we have co-produced and are testing a newly developed multi-objective decision tool, balancing conflicting management objectives for water planning under climate extremes and determining how policy alternatives perform under severe climate uncertainty. In the past year, we have completed optimization runs with a complete model of the hypothetical Front Range water management context. We have developed performance objectives for the model and used CMIP3 and CMIP5 Bureau of Reclamation downscaled climate projections to develop climate scenarios to test the utility of the MOEA tool. We conducted a workshop to evaluate how water managers interacted with the tool and understand its use in potential future decisions. WWA collaborators contributed significant expertise in the design and conduct of the workshop. A dissertation project is being completed summarizing the results of these experiments and tool testing.