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Summer 2004
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Online Only Article Metro Sewer District of Louisville/Jefferson County, Kentucky

Web-Based Floodplain Determination Served on the Web With GIS

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The floodplain administrator viewer is opened by clicking the appropriate link in the floodplain administrator list. It is used to identify the property's flood zone, to submit the findings, and to complete the request.

Situated in a low-lying fluvial plain along the Ohio River, Louisville, Kentucky, has a long history of flooding. In the last century there have been several major floods that have cost the community millions of dollars in damage. As a result of the catastrophic flood of 1937, flood protection structures have been placed surrounding Louisville's urban core. Today's flood concerns are directed toward other low-lying areas adjacent to natural streams and ditch networks, which were constructed to drain what were once wetland areas and ultimately empty into the river. As of 1994, property development within the community has been regulated according to the United States Federal Emergency Management Agency (FEMA) guidelines that primarily affect those areas.

With the release of the Metropolitan Sewer District (MSD) Web-based Floodplain Determination Service, obtaining floodplain information for individual properties in the community has become easier. Owners of properties within the floodplain who have a federally backed mortgage are required to purchase and maintain flood insurance. The floodplain is defined by the normal channel of rivers, creeks, streams, and areas where overflow occurs when the capacity of the waterway is surpassed during a 100-year flood event. The Flood Insurance Rate Map (FIRM) was created by FEMA to delineate these floodplain boundaries. MSD has been performing floodplain determinations in accordance with FEMA guidelines for more than 10 years and has identified the following as core customers of this service: condominium associations, home owners, insurance professionals, lenders, state and local officials, and surveyors.

A History of Floodplain Determination

In the predigital days, MSD staff performed floodplain determinations manually using hard-copy FIRM maps. FIRM was offered digitally for the first time in the community in 1994 as the result of a countywide restudy by FEMA. This effort served as a model project for FEMA in methods of utilizing GIS to maintain data. A workstation-based application was developed in-house by the Louisville/Jefferson County Information Consortium (LOJIC) GIS, in which MSD is a partner, to automate much of the flood determination process utilizing digital data.

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The floodplain administrator page lists all incomplete requests that require a visual determination by MSD staff.

That application served its purpose well for several years. In that time, as the volume of floodplain determination requests increased, a full-time technician was needed to process the requests. It became apparent that a new solution was needed. Recently, MSD initiated a businesswide study to streamline work flows and increase efficiency. Floodplain determination was identified as a task that could be reengineered to free up personnel for other core services.

Web-Based Solution

MSD GIS and LOJIC staff teamed up with the goal of implementing a new solution with the following objectives:

  • Reduce staff resources.
  • Shorten response time to customers.
  • Increase availability for customers.
  • Automate request tracking.
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Showing a completed floodplain determination form required by lenders and insurance representatives.

MSD and LOJIC are no strangers to Esri software, and the technical team recognized early on that the project should be implemented as an ArcIMS solution. In fact, two applications were developed to accommodate this project: the Floodplain Determination Application and the Floodplain Administrator Application. The Determination Application serves as a front end to an ArcIMS map service that allows the user to enter property and contact information. The location information is used to perform a series of spatial queries against the ArcIMS map service, and the results form is returned in PDF format. A majority of the requests can be automatically determined, and the corresponding results are immediately displayed on the customer's computer screen. The remaining requests require a visual determination because of the accuracy required for the floodplain determination and the time lag involved in updating the county's planimetric/topographic basemaps in the GIS. These requests are tracked in the Administrator Application, which is accessible only to MSD staff.

In the Administrator Application, the MSD staff reviews each request by clicking its corresponding link, and an ArcIMS viewer quickly appears zoomed to the property's location with appropriate layers visible. To complete the request, the MSD staff reviews the map, determines the flood zone, and submits the findings. Once the request is completed, the form is generated and a link to it is automatically e-mailed to the customer's e-mail address, if one is provided. If an e-mail address is not available, the request is printed out and faxed back to the customer.

The Determination Application page includes links to FEMA, MSD's Floodplain Management Plan, and MSD's Stormwater and Sanitary pages for quick reference. Also included are an instructions page and an FAQ page for the Determination Application and Help documentation for the Administrator Application.

Measure of Success

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The floodplain determination main page is where the user enters location and contact information and then submits a floodplain determination request.

This ArcIMS solution has successfully accomplished the following objectives:

  • Reduced staff resources: MSD staff time spent on flood determinations is now less than one-quarter of what it once was. In fact, 87 percent of all requests are now automatically completed.
  • Provided quicker response time: In most cases the results are returned to the customer immediately, in contrast to within two business days as before.
  • Increased availability: The Web service is available 24 hours a day, seven days a week, in contrast to normal business hours previously.
  • Automated request tracking: All request information is automatically inserted into MSD's customer request management system.

With the new service in place, MSD is taking steps to phase out accepting floodplain determination requests via fax to further reduce staff time. The Web-based floodplain determination service is free for public use.

For more information, visit or contact Brian Meyers, MSD (e-mail:, tel.: 502-540-6379), or Julie Buckler, MSD (e-mail:, tel.: 502-540-6443).

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