An area that was once vernal pools can probably be restored, but simply knocking down the buildings would not be enough. Patience and thoughtful study are also necessary. If extra soil or rocks were brought in to fill the pools, that would need to be removed. Original native species would have to be reintroduced to the area and non-native species should be removed. Of course any species that have become extinct, are lost forever.

If migrating birds that once used the pools have forgotten about them, it might take sometime for them to return. It might take some years for the water balance and species to return to what they were, but eventually it is very likely that the vernal pools would be restored. The best option is to preserve at least some of the pools before they are built over. Do you have pools in your area?

I've read that vernal pools can be redeveloped to be almost identical to the pools that were once there. The only difference was that the new vernal pools didn't have as deep a layer of organic sediment on the bottom.

These vernal pools were in places such as west campus at UCSB and open space in Isla Vista. But these vernal pools were developed by scientists on open space, not where buildings were. I think vernal pools would grow back after the buildings were gone, too.

If you walk around open spaces on west campus UCSB, or near Lake Los Carneros, you can find traces of asphalt roads and the foundations of buildings that are almost hidden by plants now.