This paper compares engineering efforts using Computer Aided Design and Drafting (CADD) to similar efforts required by classic manual drafting procedure in the design of a modern water treatment plant. The greatest impact the CADD method made was in the plant process and instrumentation development. The CADD approach is to search back through process diagrams on file among prior projects and edit out electronically those functions that are not applicable to the current requirements. The value of repetitive use of common graphics by CADD cannot be overstressed. Manipulations during development revealed the forgiving nature of the CADD system toward changes. Written entries, such as notes and legends, can be edited without notice in the final work. Although the structured text follows the personality of the operator, editing can be made by a different operator at a later date without adversely affecting the work or showing a conflict in drafting styles. Finally, CADD offers uniformity and easy reproduction.