Alternator Bracket, Coolant question

[300SDowner]

I've got an 84 300SD and right now the engine is on the stand in the garage. I'm replacing ton's of gasktes, o-rings, parts, etc... before reinstallation. I took off the alternator bracket that is mounted to the engine block to degrease it. Upon breaking it loose from the block there was some coolant and water that leaked out from behind the bracket. There is a hole that is machined into the block that must lead to a water passage. What is the point of this and is this normal? Do I need to "fix" something else? All help will be appreciated. Thanks Mike.