Another advantage is the repopulation of fish and animals. If we can use the water initially to build new reservoirs, we could create lake effect rain, and then create rivers for fish to the ocean. then, the economy could fish that, hunt that for good meat rather than farm fattened. It could be literally a poaching industry, but we breed more than we poach. Also, you dont give someone an animal to torture and cage, but offering some of these super endangered ones as pets would have safety advantages rather than the wild.
Bugs- Monarchs from mexico type restorations. We need to combat the invasive species coming from shipping containers and attacks, tough to do. Harder than water problems. You can't introduce yet another species, you cannot adapt the current species though rattle snakes did with pigs. also in that example now we cant hear a rattler before we step on it now. we have to be very careful. I think fostering the current species will counter this naturally however, and we have enough people to squash the bad bugs :)