I posed the question to the CAP board candidates that maybe we should be looking at reallocation of existing water supplies before we commit ourselves to building nuclear power plants in Mexico that will power massive desalting facilities. Of the four candidates present, one understood the question but deftly sidestepped the issue, two flatly stated that reallocation was a non-starter because of the mess it would create (but they were assuming that the question referred to simply taking away water rights from one party and giving them to another), and the fourth never even addressed the question in his rambling response. Anyway, the idea that reallocation of water should not even be on the table is pure bunk. There should be ample opportunity for cities or communities to enter agreements with agricultural users to free up irrigation water for municipal uses - all you need are two willing parties and agreement on price.
In a sense, this is what is already occuring in the cleverly named Groundwater Savings Facilities, where farmers agree to purchase subsidized CAP water, use it for irrigation in lieu of groundwater they are entitled to pump, while a nearby water provider (who provides the subsidy for CAP water) accumulates groundwater credits (that otherwise would go to the farmer) that can be used to permit future pumping. As was pointed out at the forum, this is a particularly good deal because it uses lower quality CAP water for irrigation, while permitting use of higher quality groundwater for residential uses.
It's quite possible there is not much excess water in the ag sector that could be moved to other uses through such agreements, but because so much water is used by ag a very small reduction in that sector could provide a very significant amount of water for the municipal sector - which should serve to minimize the economic disruption caused by decreased irrigation.
Additionally, the most likely scenario in which CAP would need to secure additional supplies to meet its obligations, would be in the event of long-term drought leading to cutbacks in Colorado deliveries, under the recently completed Shortage Sharing Agreement among the Colorado basin states. And what is the result when that agreement kicks in? Water deliveries to ag users are cut back first, so that CAP's municipal obligations are not threatened. This sounds like reallocation of water between use sectors to me. In a really major drought, where these shortages occur for several consecutive years, farmers will be going out of business in large numbers, resulting in permanent reallocation - which should eliminate the need for supply augmentation.
I know - talk of moving water from ag to municipal is a tough sell politically. But to simply ignore the possible need to do so in the future to meet changing water supply needs is not just short-sighted, it may be dishonest to the voters.