is it ok to use could be with past, present and future actions.
the bridge could be removed yesterday but they decided to do it today.
the bridge could be removed today .
There are chances that the bridge could be removed tomorrow by this time.
It's fine with non-past, but it doesn't work with past. The first needs to be could have been removed.
Note that 2 unambiguously refers to the part of today starting from now: if you're referring to earlier today, that also needs to be could have been removed.