The City of Los Angeles, with it's more than 1 million residents, is one of the largest metropolitan cities in the United States. Having more than 10,000 acres of commercial and residential landuse falling within the 100-year floodplain, Los Angeles has its share of problems with public safety and health as it relates to stormwater drainage. Additionally, the topography and often-severe weather, subjects many communities of Los Angeles to frequent localized flooding. To mitigate these conditions, the City manages an enormous number of stormdrain catch basins and conduits which re-direct storm-waters to local channels and eventually to the sea.

Protecting the safety, health and welfare of the City's residents, is one of the primary goals of the Los Angeles Stormwater Management Division. The proper mapping of these areas of the City are critical to an adequate floodplain management strategy and, the protection of the City's residents. As part of a several year program, the City of Los Angeles has entered into a far-reaching program which encompasses the GIS mapping of all stormdrain facilities, FEMA floodplains and applications to utilize this data.

As with most large municipalities within the nation, Los Angeles has developed a series of broad-ranged flood management programs to meet with FEMA's National Flood Insurance Program (NFIP) guidelines. FEMA's Federal Insurance Administration runs the NFIP which makes flood insurance available to residents of communities that adopt and enforce floodplain management ordinances which represent sound land use practices. More than 18,000 communities participate and more than 3 million home and business policies are in force.

Floodplain management responsibilities are shared among federal, state, regional, and local governments. It is however, the local governments like Los Angeles, that have the most direct control in floodplain management through landuse planning and regulation, land acquisition and management, and as sponsors of the flood insurance program. With a city the size of Los Angeles administering such a large program for homes and businesses, it only seems fit that a database management system like GIS, play a critical role in managing it all.

One of the primary goals of the flood insurance program is to improve public safety and health. Additionally however, there are local government based incentives to follow the guidelines and implement positive, forward-thinking flood abatement programs. The most notable of these incentives is a federal review of municipal programs. Once a review has taken place, a city is given a rating for their program. In the event that the city's program has improved the rating, the outcome results in lower flood insurance premiums for the citizens and businesses that need to obtain flood insurance.

This paper presents one of the many applications that have been developed by Psomas and Associates to provide unique and creative solutions in floodplain mitigation for the City of Los Angeles. The application described herein, has provided the City of Los Angeles a robust toolkit which has allowed staff to query, visualize and report on stormwater related data within seconds. Psomas and Associates have also helped to develop a standardized and consistent response to stormwater related questions from the public. Moreover, the long-term implications of this paper's application indicate that data and resources that have been collected may be available via the Web, in a short period of time.

With respect to the project application's objectives, Psomas and Associates has successfully met with Stormwater Management Division's expectations. The Floodplain Determination application is helping the Stormwater Management Division meet with the National Flood Insurance Program guidelines. Additionally, the work-flow procedures have been stream-lined to allow more staffing hours on important safety and health related projects.

The GIS application technology that has been described will be a strategic element to Stormwater Management Division's service to the public. Further enhancements and additional NFIP related applications will continue to move the City of Los Angeles into the future using GIS.

With technology ever-changing in the GIS industry, it often times seems unclear as to the right direction to take with using software. During this project however, it has become more apparent that the integration of both MapObjects and Visual Basic is a solution that provides for enormous flexibility. Additionally, these technologies are somewhat seamless in their transition to the Internet. After all, it is the Internet that will ultimately become the purveyor of public information.

My personal gratitude goes to Guchuan Liu. He has made this project application a remarkable success for the Stormwater Management Division. Additional thanks go out to the remainder of the project team whom have worked so diligently on the design, development and implementation of the Floodplain Determination application.