Now that the feature classes have been renamed, you will see how to create a topology to regulate certain spatial relationships between and within these feature classes.

The default cluster tolerance is the XY Tolerance of the dataset. Parts of features within 0.001 meters of each other will be snapped together when the topology is validated. The cluster tolerance cannot be made smaller than the XY Tolerance, although it can be made larger. Increasing the cluster tolerance to 0.5, for example, would cause vertices of features within 0.5 meters of each other to be snapped together in topology clustering. For this exercise, you will accept the default name and cluster tolerance.

The watershed feature class contains the least accurate data in the dataset. It was heads-up digitized around the streams upstream from the reservoir to create an approximate boundary. Since it is lower quality data, you should set it to a lower rank of 5. This will prevent features in higher ranking feature classes from being snapped to it when the topology is validated. The other feature classes are all of equal accuracy, so the rank will be left 1.

The next step is to define topology rules. There are a number of spatial relationships that this topology will control. You want to be sure that features in all the feature classes do not overlap, that the area features in the floodzones and waterbodies feature classes do not overlap each other, and that the stream features do not have pseudonodes.

To manually add a topology rule, click Add Rule, then click the Features of feature class dropdown arrow and click a feature class (in this case it is streams). Next click the Rule dropdown arrow and click a rule (in this case the Must Not Overlap rule), and click OK. The rule is added to the list on the wizard.

You would ordinarily continue adding topology rules for each of the topological relationships that you want to define. The rules for this topology have been stored in a rule set file, so you can load them.

To load topology rules from a file, click Load Rules, navigate to the location where the rule file is stored (in this case, the TopologyData folder). Rule files have a '.rul' file extension. Click the rule file and click Open.

If the feature classes mentioned in the rules do not have the same names as the feature classes in the dataset, you can use the Load Rules dialog box to match them.