Launches the Interpolate Hydrant Elevation dialog box as shown below and calculates and assigns an elevation to UDF hydrant database. 

Update Elevation to Hydrant Layer - Select this option to update the interpolated elevation values to the UDF hydrant layer.

Hydrant Elevation Field - Select the hydrant elevation field to update.

Update Elevation to UDF Database - Select this option to update the interpolated elevations to the UDF database.

Apply to 0 or Blank Values Only - Apply interpolated elevations only to blank or zero database entries. Do not change or overwrite existing elevations.

Interpolate - Select this button to calculate hydrant elevations.

Close - Close the Interpolate Hydrant Elevation window.