Could we rewrite the sentence 'This river is as much as five kilometres wide as it nears the sea' into 'This river is as wide as five kilometres as it nears the sea'?

Another question: We say 'I walked as far as the bridge', but can we say 'I walked as far as three miles'? Some of the grammar books I read say that 'as far as' cannot be followed by such expressions as 'three miles/ ten kilometres'.

Thank you.