The Intersection of Cadastral Surveys and Floodplain Maps

The Intersection of Cadastral Surveys and Floodplain Maps in GIS Daniel Dean Yates Undergraduate Department of Civil Engineering The University of Texas at Austin

The Cadastral Map Cadastral – adj. , showing or recording property boundaries, subdivision lines, buildings, and related details. Commonly used for tax purposes Often referred to as plat maps Source: The Cadastral Map in the Service of The State, Kain and Baigent, 1992

The Yates Parcel Plat map with delineated property parcels “A plot rightly drawn by true information, describeth so the lively image of a mannor, and every branch and member of the same, as the lord sitting in his chayre, may see what he hath, and where he lyeth, and in whole use and occupation of every particular is upon suddaine view. ” Surveyor’s Dialogue by John Norden, 1607 Source: The Cadastral Map in the Service of The State, Kain and Baigent, 1992

Travis County Parcels Close up of Travis County Parcels and Structures Source: Lower Colorado River Authority

Travis County Parcels and The LCRA 100 Year Floodplain

Fun with Databases

Joining the tax appraisal roll database with the parcels

Organizing the Data Separating the parcels by city

Taking a closer look at Lago Vista Selecting by attribute and exporting data as a shapefile

Taking a closer look…

Spatial Join

Improvement Values by City 3176 structures intersecting the 100 yr Floodplain

Del Valle Neighborhood

Del Valle Neighborhood

Thanks Lower Colorado River Authority – Wes Birdwell, John Mc. Leod, Sunny Simpkins The University of Texas at Austin – Dr. David Maidment

Questions ? Boathouse going over Austin Dam, 1935 Flood