Feature Some areas of concern are not shown on FEMA maps. The area marked by red dots shows that the localized flood study (rendered in green hatch) identifies potential flood zones that were not included in FEMA maps (rendered in solid dark gray). also for future developments in the same area. Because flood studies are based on topographic features, these studies can provide floodspecific information for adjacent areas and supply required information for future developments. Even if a study is contained within the area, that study can be used as the basis for future studies of adjacent areas. In both scenarios, access to this information can substantially reduce costs. If existing studies are not available, residential and commercial developers must perform expensive flood studies to determine the BFE for a site. To relieve individual parcel owners or developers with projects of less than five acres of this expense, the county also accepts an alternative method of compliance. It specifies that new structures be built three feet above the "highest adjacent grade" (i.e., the highest elevation on the lot) if a BFE is unavailable. Although this meets the county requirement, a lack of information can result in requiring a parcel owner to pay a lot for flood insurance. Consequently, individual owners can benefit from going through old flood studies of adjacent properties. This information can not only save money on flood insurance but also help owners choose appropriate construction materials and techniques. Making Studies Accessible Currently, flood studies are available only as paper documents. To respond to a request to determine if property is located in an area prone to flooding (and must meet FEMA floodplain management requirements), legal descriptions are used to locate the parcel on an appropriate study and get pertinent information. This process, which is tedious and lengthy and wastes staff time, has all the limitations of paper-based media in terms of archiving, organizing, and searching flood studies. Sometimes flood studies are divided into parts and represented in several drawings. It is inconvenient to combine these paper drawings so the whole picture can be seen. It is also challenging to view these studies in conjunction with other data. This is a long, painstaking, manual process. To use these studies more effectively, the Land Development Division decided to convert them from paper to a digital format so the department could find the information quickly and would make flood studies accessible to a wider audience. They could be seamlessly analyzed and explored in the context of other relevant data. GIS was the obvious answer. Converting these flood studies to GIS layers would allow users to take advantage of sophisticated analysis Continued on page 36 www.esri.com ArcUser Fall 2010 35