Interoperable sharing of groundwater data across international boarders is essential for the proper management of global water resources. However storage and management of groundwater data is often times distributed across many agencies or organizations. Furthermore these data may be represented in disparate proprietary formats, posing a significant challenge for integration. For this reason standard data models are required to achieve interoperability across geographical and political boundaries. The GroundWater Markup Language 1.0 (GWML1) was developed in 2010 as an extension of the Geography Markup Language (GML) in order to support groundwater data exchange within Spatial Data Infrastructures (SDI). In 2013, development of GWML2 was initiated under the sponsorship of the Open Geospatial Consortium (OGC) for intended adoption by the international community as the authoritative standard for the transfer of groundwater feature data, including data about water wells, aquifers, and related entities. GWML2 harmonizes GWML1 and the EU's INSPIRE models related to geology and hydrogeology. Develop Use Cases Evaluate Existing Models Develop/Extend Model Test ModelDocument Use Cases 1. Commercial This use-case involves identifying the location and properties of water wells, to inform drillers and the public about local environmental conditions. 2. Policy This use case involves the delivery of groundwater quantity information required for water management reporting purposes 3. Environmental This use case involves serving the appropriate groundwater information to allow environmental managers, water managers and legislators to assess the risks to GDEs. 4. Scientific This use case involves the delivery of information required to help determine the flow of groundwater within a particular terrain, likely for input into a computational flow modeling software. 5. Technologic This use case involves using the schema as a canonical structure into which heterogeneous ground-water data formats are transformed. 1.Finalize the GML-XML UML model and XSD schema 2.Generate GML-XML instance documents 3.Develop services required to test use cases 4.Evaluate services against use cases 5.Development of an engineering report 6.Submit for review and approval by the OGC The GroundWaterML2 Logical and XML schemas are organized into 5 modular packages: 1.GWML2-Main: core elements such as aquifers, their pores, and fluid bodies. 2.GWML2-Constituent: the biologic, chemical, and material elements of a fluid body. 3.GWML2-Flow: groundwater flow within and between containers. 4.GWML2-Well: water wells, springs, and monitoring sites. 5.GWML2-WellConstruction: the components used to construct a well. Need UML of overall schema (packages) Conceptual (UML): a technology-neutral schema denoting the semantics of the domain Logical (UML): a GML-specific schema that incorporates the OGC suite of standards XML schema (XSD): one possible syntactical encoding of the logical schema.