The City of San Francisco's Water Distribution Department uses "Gatebooks" to maintain and operate the City's water distribution system (WDS). Consisting of hardcopy published maps in a bound book, this combination of water distribution maps and supporting textural information is the primary information resource for performing their mission. CH2M HILL began a pilot project in March of 1998 to establish the same information in digital format. Specifications for the automation of both graphic and corresponding attribute information were developed and used to successfully produce two prototype map pages in ArcView. As a result of this proof-of-concept, the City's Water Distribution Department (CWDD) has requested that the pilot project be expanded into a citywide Gatebook Geographic Information System (GIS) according to the formats and configurations defined in the pilot project.
The various components involved to establish the desired GIS include the data conversion to establish digital database design along with a Graphical User Interface (GUI) to expedite its data maintenance and the performance of key water system analysis procedures using ArcView. The other component of this GIS is the training of CWDD staff in the use of the data model and GUI to make it possible for them to improve the operational efficiency and effectiveness of City's water distribution system.
The Gatebook, named after gate valves, consists of 200 hand-drawn maps of 11x17-inch size at 1 inch = 200 feet scale (a portion of a map is shown in Figure 1). Wherever necessary, a street intersection with crowded installation is referred to a blank space available on the map or to another map called a "detailed drawing". There are over 100 such detailed drawings at 1 inch to 50 feet scale. As the location of all water distribution installations (valves and pipes), referred here as "map features" are relative to each other and the property boundaries around them, 215 pages of attribute data exists in the Gatebook as shown in Figure 2. This attribute data referred as "valve directions" determine the size, type, location, and direction of each valve from two nearest property boundaries or curb lines.
The WDS consists of over 1300 miles of pipeline network connected with about 45,000 valves of 17 types and about 8,000 hydrants. The water supply is streamed through 12 reservoir systems pressurized with 18 pump stations.
The operators of the system and users of the Gatebook are called Gatemen. Twelve Gatemen with help from supporting staff are responsible for maintaining the entire system. Any change (addition, removal, or change in system configuration) made by a Gateman is distributed among other Gatemen to incorporate in their Gatebooks manually to keep all Gatebooks current.
CH2M HILL along with 3 other consulting companies, GETOPO, BIK WAH International, and Olivia Chen Consultants, has been awarded to turn the existing Gatebook into an electronic Gatebook using GIS. A phased approach has been adopted to expedite the automation effort so the data is made available for use by the Gatemen as soon as it is converted. A comprehensive GUI analogous to the present use of the Gatebook has been built in ArcView. Once finished completely, the GIS database and the GUI will be made available on rugged outdoor laptops installed in maintenance trucks to be used by the Gatemen.
A 5-step process approach has been followed to accomplish the GIS implementation. These steps are:
A pilot study of 2 map pages was assigned to CH2M HILL initially to validate the proof of concept. A user needs assessment was performed to understand their business process, to know what they want to accomplish with the Gatebook automation, and to involve them at an early stage of the GIS implementation. CH2M HILL staff met with the selected staff from the CWDD, the Engineering Department, and the Bureau of Management Information Systems Department. The use of Gatebook was further understood by the CH2M HILL staff accompanying Gatemen while working on site.
The functionality of the GUI to be built was completely outlined and database fields were identified in the user needs assessment meetings. Also, two other utilities, East Bay Municipal Utility District (EBMUD) and Marin Municipal Water District (MMWD) were visited by the CWDD and CH2M HILL staff to study their GISs. A report summarizing the findings of the user needs was prepared and submitted to the CWDD staff to agree upon to develop the scope of work for GIS implementation.
The GIS database has been designed to incorporate the GUI functionality and database fields identified during the user needs assessment. The data fields structures, characteristics, and relationships were defined to accommodate present and future data associated with the WDS. A quality assurance and quality control (QA/QC) plan was also outlined to check the completeness, accuracy, and validity of the data to be produced before it is delivered to CWDD.
The database development involved scanning the paper maps from the Gatebook and digitizing while registering to the City's base map. The base map, developed from aerial photography conducted in 1996 and 2000, was made available to the consultants by the City's Office of Geographic Data Services, Department of Public Works (DPW). All features from the Gatebook maps were digitized one map at a time. The digitized data was then converted into ArcInfo coverages. The valves and pipes were kept in the same coverage to share a line-node topology. The coverage with line-node topology will help using this data for hydraulic modeling of the system later.
The attribute data containing valve directions have been organized in Microsoft ACCESS. The key-field VALVE-ID has been created in the coverage to relate valve directions data, organized in Microsoft Access, with the valve coverage.
Other coverages developed are for location of hydrants, pumps, reservoirs, tanks, and ground-surface elevations.
A comprehensive QA/QC plan was implemented to assure accuracy and completeness of data at every stage.
Documentation of a database is crucial for long-term use and maintenance of the system. The database and GUI developed has been documented to facilitate use of the database. Also, the data conversion procedures, QA/QC procedures, and guidelines (to modify the existing information in the database or to update the database with new information to maintain the quality and integrity of the database) have been addressed in the documentation.
The documentation also includes a metadata information comprising of data identification, data quality, data dictionary, spatial data organization, spatial reference, and attributes.
Protocols and schedule for data transfer have been set in the start of the project. The data is being transferred at completion of each phase so the CWDD staff can validate and use the database.
All Gatemen have been provided with the training to use ArcView and the GUI. Two personnel at CWDD have been trained to update and modify data in ArcEdit using menus written in Arc Macro Language (AML) for this purpose.
One of the major tasks of this project was data conversion. All features (pipes, valves, hydrants, tanks, reservoirs, pump stations, and groundwater elevation) had to be digitized. GEOTOPO and BIK WAH International undertook this task. Specifications and instructions to digitize all features as accurately as can be to match with paper maps were written. A portion of such instructions is show in Figure 3. A DXF file containing map features in pre-defined layers was produced for the map. The attribute data (valve type, pipes diameter) associated with map features were picked while digitizing was performed and made part of the DXF file
The DXF files were then converted into ArcInfo coverages using AMLs written for the conversion and an appropriate topology was built. These coverages were brought into ArcView to compare with paper maps. Any discrepancies denoting valve type, pipe diameter, valve and hydrant orientation and location, and missing features were documented in a QA/QC report.
The discrepancies identified in the QA/QC report were resolved in ArcEdit using ArcInfo menus such as shown in Figure 4.
Next, all valves in the coverage were assigned unique IDs. The same Ids were assigned to the corresponding valve directions record in Microsoft Access database to relate this information with valve locations via SQL connect in ArcView using Open Database Connectivity (ODBC).
Final QA/AC performed include edge matching at map boundaries, duplicate valve ids, valve type and size, pipe diameter, and reservoir system.
A GUI has been developed using ArcView's Avenue language to incorporate database developed and functions identified during the user need assessment. The opening view of the GUI with Gatebook pages (maps) finished for Phase I is as shown in Figure 5.
Several buttons and tools have been developed in the GUI to achieve different functions. Following is a brief description of these buttons.
As of June 2000, the first two phases comprising 107 out of 200 Gatebook pages have been finished. Phase III has just started and plan is to finish all pages by end of year 2000.
The project has been a real success as all Gatemen like the way the data is available to them with a user friendly GUI. Another factor that contributed to the success of the project is early involvement of the users and determination of their GIS needs during the users need assessment.
