Aren’t these options to develop Habitat or General Conservation Plans already available? Yes. The big difference is that settlement provides a budget to assist with these plans, guidance to FWS to help in the preparation of plans, and recognition from Tribes, environmental groups and commercial fishing groups that Off Project landowners are supporting settlement proposals to improve conditions for endangered species (dam removal, increased flows, restoration).
The difference could be thought of as going it alone to try to get exemptions from “takings” under the ESA, vs. having support from many of the parties that have traditionally been enemies on these issues. Community-based regulatory assurances have been used successfully in other parts of the country, in part because they provide economies of scale that allow large groups to do what isn’t possible for individuals.