I just looked through this set of photos you've submitted, starting with #1, and I'm guessing this project was to renew this area for public use, right? Were the raised boardwalks installed to protect the marsh from pedestrian traffic, or to keep visitors' feet clean of marsh mud, or is the marsh to be flooded to increase the acreage of water? I'm not clear on the project's purpose. [Incidentally, my son just visited southern Portugal--he's in the U.S. Navy and is on a six-month deployment to the base at Rota, across the bay from Cadiz.]
If you've ever wanted to make a difference but found it hard to believe that one person could... check out the Kiva Team Caedes discussion thread and discover that anything is possible.
-Nik