Strange noise from front of the engine

It seems the electrical water pump might be responsible for this moaning groaning noise when hot , I was just wondering if anyone had any information on the purpose of this pump , is it just for the intercooler circuit and is this separate from the main engine cooling? I've seen a used one on the bay for £139 so I guess a new one will be double that plus fitting ,not much change out of £500 I guess . If anybody has an technical info I would be glad to hear it . Otherwise four years old and still going like a rocket when I can find a bit of unclogged road!

Andrew