The objective of this term project was to do a watershed delineation on the Trinity River basin for water quality segments. At first the goal did not seem to be set high since the procedure of watershed delineation was carried out in exercise 3 in the GIS class and a similar procedure seemed to be promising for this task. The steps, however, that have to be taken before the actual delineation can be done, appeared to be quite a few and time consuming. This term project contains therefore no watershed delineation but instead a lot of preparation.