Sample Products
![Elevation-Area-Volume Tables and Graph](/surfacewater/surveys/samples/img/eav_graph_thm.jpg)
Elevation-Area-Volume Tables and Graph
The primary purpose for conducting a hydrographic survey is to determine current reservoir capacity. The TWDB provides updated area-capacity tables at 0.1-feet increments in elevation.
![Elevation Relief Map](/surfacewater/surveys/samples/img/erm_graph_thm.jpg)
Elevation Relief Map
This view of the reservoir describes the bathymetry as color coded blocks by reservoir elevation.
![Contour Map](/surfacewater/surveys/samples/img/cm_graph_thm.jpg)
Contour Map
Bathymetric contours are extracted from the raster representation of the reservoir TIN model using ArcGIS. Contour increments vary from 1 to 10-feet depending on the size, shape, and overall depth of the reservoir.