This would quickly back up behind the dam, they say.

The work itself has caused water to back up behind the dam.

As the waters rose behind the dam, the town had to be moved.

The area behind the dam will also be restored into a park once complete.

If that happens, then all the water behind the dam will flow right over where we're standing now.

The rim walls just behind the dam would very likely go as well.

The water backed up behind the dam and then broke through all at once.

Eventually, the amount of water behind the dam will increase again.

The entrance to the canal is directly behind the dam on its left bank.

When the chute was closed, water collected behind the dam.