The Institute for Geospatial Research & Education at Eastern Michigan University created the Drain District Mapping Tools with guidance from the Livingston County Drain and GIS Departments. This application was developed because Livingston County needed a simple to use but powerful set of tools that could convert their legally designated Drain District parcel descriptions into digital format. The IGRE Drain District Mapping Tools, is an ArcGIS 8.x and ArcGIS 9 Extension that creates, edits and maintains the myriad of shapes described by legally designated Drain District property descriptions, into polygons. The primary functions of the IGRE Drain District Mapping Tools are: -- Creates polygon shapes based on Section, Aliquot (fractional sections), COGO and    Lot number legal descriptions -- Handles exceptions described in legal descriptions -- Captures the point of beginning line for COGO descriptions -- Combines individual drain parcel polygons to form a single Drain District polygon    shape -- Provides a COGO style legal description for each property shape created, including    one for the Drain District itself -- Allows maintenance of individual Drain District parcels as the component parcels    change over time Drain Districts are comprised of land descriptions generally written in a variety of formats. These descriptions form the legally designated Drain District. In states where the Public Land Survey System is used, the land descriptions are comprised of Section, Aliquot (rectangular land descriptions - fractional sections, e.g. N1/2 of SE 1/4), COGO (coordinate geometry descriptions), and Lot descriptions (Lot 5, Handy Subdivision). These descriptions describe the parcel shapes that form legally designated drain assessment districts. IGRE developed this ArcGIS extension to create and maintain the shapes representing the assessment district parcels, based on these description types. Following creation of the individual parcels, they can then be combined to form the separate Drain Districts. The IGRE Drain District Mapping Tools comprise several powerful tools. The Tools Basic Funtions are: Aliquot tool: To generate polygon from Aliquot descriptions COGO tool: To generate polygon from COGO description with bearing and distance values Select Lot and Subdivide tool: To generate a new polygon from an existing lot shape and capture the COGO description Combine Selected Lot(s) tool: To combine selected lot(s) into one polygon and capture the COGO description Exception tool: To create a new polygon by subtracting one shape (the exception polygon) from another larger shape Combine Selected Drain Parcels tool: To combine selected drain parcels into a drain district polygon Combine Drain Parcels by DDName tool: To combine drain parcels with the same drain district name into a drain district polygon Legal Description Viewer: To view COGO descriptions of selected features and drain districts Options tool: To set necessary parameters for use by the other tools Clear Selections tool: To unselect selected features Set Selectable layers tool: To set selectable layers for use with the various tools

mdueweke@emich.edu