Las Vegas residents tried to pass a bill that would allow homeowners to install graywater systems but the Southern Nevada Water Authority blocked it, offering up a piece of fuzzy math as a defense. Las Vegas Valley is allotted 300,000 acre-feet of water per year from the reservoir. The water that goes down drainpipes in Las Vegas gets pumped 12 miles back to a reclamation plant near Lake Mead. This returned water counts as a credit toward getting more fresh water from the lake.First, the non-sequitur [in bold]: People install greywater systems to reduce their use (hence their bill). That's different from people who do not care, who may use more water if their bill goes down (because of some outside force). This another example of the "20/80 rule" -- 20 percent of the people care about how much water they use; 80 percent only care about their bill.
The Water Authority says if people start using graywater to water their lawns and gardens rather than using drinking-quality water, their lowered water bills will dissuade them from conserving water. In other words, the Water Authority believes that legalizing graywater will cause people to use more fresh water and return less dirty water to the reclamation plant.
Second, the greywater issue is similar to SNWA's dependence on hook-up fees (more development) for revenue.
Basically, SNWA does NOT want greywater because it cannot charge for it. If greywater is NOT discharged into Lake Mead, LV cannot get a credit to take out more. If it cannot take out more, it cannot sell it to you, a person so impolite as to "cut out the middleman."
Bottom Line: Good ideas can die if they contradict the winners under the status quo.