Category:Water Supply
You can create a new category with this button. Leave the word Category: in place and add the name of your new category after it.
<inputbox> type=create default=Category: buttonlabel=Create Category </inputbox>
You will still need to enter [[Category:Water Supply]] in your new category to have it show up in this list. If you wish to include this template, then add the line {{CreateCat}} also.
In the Subcategories list, clicking on a [+] will expand the category to show subcategories if any exist.
Subcategories
This category has the following 2 subcategories, out of 2 total.
Pages in category "Water Supply"
The following 3 pages are in this category, out of 3 total.