River much the same as the Volga (5)

'the volga' is the definition.
Both the answer and definition are singular nouns.
Perhaps you can see a link between them that I don't see?

'river much the same' is the wordplay.
I cannot really understand how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is located in the answer.
The remaining letters 'vola' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).

'as' is the link.

Can you help me to learn more?