...has/had even risen before.

[Tan Elaine]

The river rose higher than it has/had even risen before.

Should I use 'has' or 'had'? Please let me know the reason for the choice.

Thanks.

 

[CarloSsS]

NOT A TEACHER

The river rose higher than it had ever risen before.

The fact that the verb "rise" is here in past tense makes the use of present perfect impossible as pp is always somehow related to the present.

 

[5jj]

It's the 'before' that makes the past perfect necessary. It is locating the point of retrospection in the past: The river rose higher than it had ever risen at any time up to that past time.

Without the 'before, the present perfect is possible.

In 2002 the river rose higher than it has ever risen. (i.e. at any time up to the the present).