While nursing documentation in electronic medical record (EMR) flowsheets may represent the largest investment of clinician time with information systems, organizations lack tools to visualize and repurpose this data for research and quality improvement. Incorporating flowsheet documentation into a clinical data repository and methods to reduce the flowsheet ontology's redundancy are described. 411 million flowsheet observations, derived from an EMR predominantly used in inpatient, outpatient oncology, and emergency room settings, were incorporated into a repository using the i2b2 framework. The local flowsheet ontology contained 720 "templates" employing 5,379 groups (2,678 distinct), 37,836 measures (13,659 distinct) containing 226,666 choices for a total size of 270,641. Aggressive pruning and clustering resulted in 150 templates, 743 groups (615 distinct), 6,950 measures (4,066 distinct) with 22,497 choices, and size of 30,371. Making nursing data accessible within i2b2 provides a new perspective for contributing clinical organizations and heightens collaboration between the academic and clinical activities.