This is EXACTLY what I have been warning people about for the last 20 years.  I have consistently stated that counties are over planning for "growth" and allowing folks to invest in property with no guarantee of water.  WATER BANK, are you kidding?  Water banking relies on "willing" water rights holders selling their rights for development purposes.  What they don't tell them is that once they sell their water rights they no longer have ANY right to continue to use the water much like selling your car or home forcing the "willing seller" to connect to a Public Water System at their own expense.  

If you doubt me on this I can provide you with quotes from the Department of Ecology.