SPARC is a cloud-served, open source GIS data transformation service and warehouse that includes the INDEX scenario planning tool. SPARC organizes GIS data from multiple organizations that are collaborating in planning projects, normalizing it to a common data schema, automatically repairing geometry defects, and providing a user account system for sharing across organizations. Users engaged in scenario planning can employ INDEX to ‘paint’ land-use and transportation concepts, score them with sustainability indicators, and rank multiple scenarios by goals achievement.