Since this is a typical Nevada mining project, this time mining water rather than ore, look to Nevada's history to provide the proper response to Ms. Mulroy's lament for Emily Green failing to postulate an alternative to the current and growing water deficit.
Ms. Mulroy sits as a mother hen guarding the welfare of her dependent chicks, doing her utmost to protect them against the natural evils that surround them. No matter how much planning, no matter how much effort, no matter how much money one spends and no matter how much noise one makes, success is not a guaranteed thing.
Let Mother Mulroy consider such names as Rhyolite, Belmont, Osceola, Goldfield, Seven Troughs, Pioche, and Tonopah. Each municipality was founded on the dreams of riches--just like Las Vegas, and lasted until the primary support of their existence either dwindled or perished.
Las Vegas could well become another Pioche or Tonopah. Both towns continue to exist, but they are no longer the metropolises they once were. Their populace did not die when the ore ran out, instead the good citizens used their good common sense and left for more amenable climes. The current populations of both towns reflect the natural ability of the environs to support as many as presently live there.
All of the aforementioned cities were established in the roughly the same types of desert found in the immediate vicinity served by SNWA. There was no guarantee of boom, growth and survival 100 (plus or minus) years ago. Go visit the stone, brick and wooden skeletons of these mighty titans of yesteryear if you should doubt it. Technology has certainly changed in the meantime, but Nature has not done so.
By the way, each of these communities--save Pioche--imported water to quench their thirst and drive their economy. Seven Troughs, located above Lovelock, perished in a flash flood. Las Vegas could succumb to the natural disaster-waiting-to-happen in which it is perpetually located. Las Vegas could quite naturally be strangled by the very desert she defies on a daily basis.
Being aware of this fact, why would any neighbor wish to fall on its sword anticipating the same fate as its willful, gluttonous sister to the south?
Nevada has many more former flashes-in-the-pan scattered about her deserts. Should the desert decide to reclaim its own, it would only be natural. Nature has already provided the definitive, lasting alternative to southern Nevada's problem. Ms. Mulroy simply refuses to accept it.
Mother Mulroy might be able to fool herself, but, as we all know, you can't fool Mother Nature.