The main point was to reduce the chance of flooding. But the effort produced other benefits as well, when Oregon's Tillamook Bay got a tidal wetland habitat restoration.
The project treated 443 acres of land (some of it quite watery) to improve salmon habitat and reduce flooding risk. There were many additional effects, including a rise in real estate values. A recent report shows how the benefits went beyond the original scope of the work.
Steve Dundas and Graham Shaw at Oregon State University did much of the study work; they visit with details.