Calculate how much that particular wetland is worth ecologically and find a low-price equivalent somewhere, buy that.
The Bay gets more space to sprawl their ugly single family madness and the wetlands (or more precisely the wetland equivalents) are safe too.
Furthermore, it's possible to simply incrementally move the wetlands toward north by filling in a southern patch and wetland-ifying some of the southern parts of the Bay's open water.
And ... this modest proposal is very much the mirror that the Valley needs. Not that it will help much, but still. It would eradicate the wetlands and the Bay itself before allowing proper high-density development and mass transit.