Would reducing 5% of water from this point in Louisiana not also have a noticeable impact and that state's environment? I could see a significant legal battle here, much bigger than we've seen in cases where other states down stream feel as though they are wronged by states upstream. Louisiana will ask itself, "to what extent will we be forced to give water to the entire US Southwest?".
Reducing the flow of water in Louisiana by 5% would not have noticeable impact on the state’s environment when you consider that annual variability of water flow must be far higher than 5% for such a vast and dynamic watershed. If that kind of annual variability is not often creating headlines, outside of flooding - for which this kind of project could only help, then it’s difficult to imagine how a far smaller variance would have meaningful impact.