The many layers of resource data accessed by TVA's eMap.

The Tennessee Valley Authority (TVA) is a U.S. federally owned corporation that was created by the TVA Act in 1933 to improve the navigability and provide flood control on the Tennessee River, the United States' fifth-largest river system. TVA provides for agricultural and industrial development, as well as restoration of degraded natural resources.

TVA continues to support these stewardship activities, including river and tributary flood control and navigation of a 652-mile-long commercial river transit channel from Knoxville, Tennessee, to Paducah, Kentucky; 150 miles of secondary commercial tributary channels; and more than 100 additional miles of tributary channels for recreational use. TVA also manages the resources of more than 11,000 miles of public shoreline, 480,000 acres of recreational lakes, and 293,000 acres of public land (including more than 122,000 acres set aside for wildlife preservation and habitat enhancement). TVA also has a comprehensive economic development program.

TVA is the country's largest public power provider, generating the electricity (currently more than 31,000-megawatt capacity) to serve more than 8.3 million people in seven states. Power is generated from the operation of 241 individual generating units at 29 hydroelectric dams, 11 fossil fuel plants, 3 nuclear plants, 5 combustion turbine plants, and 1 pumped storage plant. Power is delivered over more than 17,000 miles of transmission lines requiring more than 130,000 line-supporting structures, 850 delivery and interchange points, and 675 primary power transmission facilities comprising 486 substations and 189 metering locations. While TVA provides power directly to 54 large industrial power users and eight federal installations, the vast majority of TVA's retail, commercial, and residential power is provided by 158 retail power distributors. TVA staff are based in Muscle Shoals, Alabama; Chattanooga, Knoxville, and Nashville, Tennessee; and a number of regional customer service and resource management centers.

One important aspect of TVA's operations is the tracking of landownership, including agreements for interim and long-term uses of federal property between TVA and private, state, and other federal agencies. TVA land managers must access a variety of data before making determinations for requests, such as issuing new permits for the construction of private boat docks or other water-use facilities. Land managers must also be able to verify that newly permitted boat docks or other water-use facilities meet requirements for placement, aesthetics, and safety to others.

	Both images: TVA land managers use eMap forms and maps to track land rights and monitor shoreline development.

TVA has been a longtime user of Esri GIS to support the many aspects of its integrated resource management mission, including evaluation of siting alternatives for TVA projects, flood damage assessment, water quality management, and management of TVA reservoir lands. The Resource Stewardship Information System Integration Project (ISIP) is composed of many layers of information pertaining to TVA land rights, including fee lands. The system also includes disposals (sales or transfers), ownership, land-use permits, special use permits, and easements. Related resources information, such as eroded shoreline to be repaired and sensitive areas, wetlands, and archaeological sites that could influence the location of particular facilities, is also maintained. All this data is stored in TVA's enterprise GIS using ArcSDE.

TVA needed an efficient way for land managers to evaluate real-time data before issuing land-use permits on the reservoir shoreline or public lands. It also needed a way to monitor the status of private facilities along the shoreline and locate violations and encroachments on TVA lands and waterways.

Since the ISIP data is stored within ArcSDE, TVA chose to continue using Esri GIS software to gain access to this data. Most TVA desktops are not equipped with GIS software, and many land managers have little or no experience using GIS. The organization decided to use ArcIMS to deliver the necessary GIS data over the Web to its land managers. TVA made the application as simple as possible by creating a user application on top of ArcIMS, called eMap. The eMap application allows users and managers to access, view, and query the TVA ISIP data through an easy-to-understand user interface.

The eMap application is built on top of the Esri Java Integration Toolkit (JITK) and is a JavaServer Pages (JSP) viewer. The eMap Web application is available over the TVA intranet, allowing managers to view the inventory of data; generate maps; and create external datasets, such as landowner information. Managers have found the application intuitive, eliminating the requirement for intensive training. Managers now use eMap to perform in-depth spatial and data analyses.

ArcIMS Metadata Services is also used to create a central, online metadata repository allowing TVA to easily publish and browse metadata for the ISIP database and other geospatial data over the intranet. The metadata is published through an ArcGIS Desktop application using industry-standard and user-definable style templates. ArcIMS Metadata Services allows for the metadata to be optimized for rapid and efficient searches using a variety of clients, including lightweight browser-based clients like eMap and ArcGIS Desktop. Searching for metadata is quick and efficient now, as users can perform searches based on any combination of geographic extent, content type, data format, or keyword.

TVA's eMap application allows users to access enterprise-wide data while in the office or using a wireless network in the field. Users and managers now make better decisions about land- and water-related issues and identify problems involving violations and encroachments. This cost-effective application promotes information collaboration, as well as data consistency and sharing, while helping watershed planners make and monitor land/water management decisions and design and implement water quality improvement and protection projects. It also allows users to coordinate requests with other users, providing a tracking system to monitor the coordination.

More Information

For more information about GIS applications at TVA, contact Roy J. Teal, senior manager, Geographic Information and Engineering, Tennessee Valley Authority (tel.: 423-751-6635, e-mail: rjteal@tva.gov).