Washington Surface Water Identification System

The Washington Surface Water Identification System (WASWIS) makes use of the dynamic segmentation model to alleviate many of the difficulties associated with managing a large, dense, dynamic database. Accessed through a graphic user interface, WASWIS identifies and locates the state of Washington's surface water features at 1:24,000 scale. It provides users with query and plotting tools to support data browsing, reporting, conversion, and cartographic output. It also allows users to cross reference to two previously existing identification systems, EPA River Reach and Washington Department of Fisheries Stream Catalogue. Additionally, the system can be used in both GIS and tabular formats.

Through the implementation of a route and non-measurement based index system, attribute information for the system's linework is accessed via event tables. For a large and very dense data layer, this method provides a highly desirable means for retaining information, without dividing the arcs for attribute attachment and thus incurring excessive storage. The indexing system can easily be updated to accommodate changes in surface water features, yet still readily access historic data for comparison purposes.

The system provides an extensive amount of identifiers (46 million) for unique identification of surface water features within a minimal six place format. The user interface provides simple to complex query information for both the casual browser and the serious GIS user, allowing for graphic display and cartographic output for meetings and field surveys. Its recent beta release has resulted in a highly positive response from the user community. Pilot implementations of WASWIS for watershed analysis have also resulted favorably, especially in the areas of conversion of data from multiple systems and formats into WASWIS. Highlights of the system include:

• A standard, comprehensive means for identifying extensive amounts of features and for referencing and exchanging information in both GIS and tabular formats
• Utilization of unique, non-intelligent identifiers for feature identification
• Non-measurement based address system supported by dynamic segmentation to accommodate the dynamic characteristics of the features
• Cross reference capabilities to existing systems - EPA Reach (1:100,000), Washington Dept. of Fisheries ID system (1:24,000), and adjoining states and provinces
• Updating while retaining identification system integrity and capabilities for historic comparison
• Scale independence for implementation at local levels
• Capabilities for input using formats of multiple types

The system supports the state's need for data exchange capabilities, and subsequently will reduce the redundancy that currently exists in data collection efforts.

Cathleen Vanzwol
Washington Dept. of Ecology
Water Resources Program
P.O. Box 47600
Olympia, WA 98504-7600
Telephone: 360-407-7295
Fax: 360-407-7162
Email: cvan461@ecy.wa.gov