Yes it is.
Sometimes the leak appears at the bottom, but is actually coming from one of the pipes on top.
To be sure cover the top of the heater with paper towels for a moment, for a visual inspection of water.
Another thing to be aware of is the water pressure. When replacing a water heater, the installer should always check water pressure to verify that there are no problems before installing a new heater.
The Local Plumber
Tustin, California http://www.TheLocalPlumber.com
[Edited by TheLocalPlumber on 08 October 2000]