HydroShare is an online, collaborative system being developed for open sharing of hydrologic data and models. The goal of HydroShare is to enable hydrology researchers to easily discover and access hydrologic data and models, retrieve them to their desktop for local analysis and perform analyses in a distributed computing environment that may include grid, cloud or high performance computing. Users may also share and publish outcomes (data, results or models) into HydroShare, using the system as a collaboration platform. HydroShare is expanding the data sharing capability of the CUAHSI Hydrologic Information System by broadening the classes of data accommodated. HydroShare will take advantage of emerging social media functionality to enhance information about and collaboration aloud hydrologic data and models. One of the fundamental concepts in HydroShare is that of a resource. All content is represented using a Resource Data Model that has elements common to all resources as well as elements specific to the types of resources HydroShare will support. These will include different data types used in the hydrology community and interface and social media functions are being developed using the Django web application framework. A geospatial visualization and analysis component enables searching, visualizing, and analyzing geographic datasets. The integrated Rule-Oriented Data System (iRODS) is being used to manage federated data content and perform rule-based background actions on data and model resources, including the execution of models and workflows. This paper introduces the HydroShare functionality developed to data and elaborates on the representation of hydrologic data and models in this system as resources for collaboration.