Good to see a crusty old (but still pedaling) water engineer delve into the basis and practicalities of a Grand Bargain for the Colorado River; such thinking is sorely needed as this river system barrels towards the opportunity of disaster.

This comment about footnote 28: Any percent apportionments for environmental flows will be inversely related to the percents apportioned for consumptive use across the Upper Basin, Lower Basin and Mexico. That is, leaving any of the natural supply at Lee Ferry undepleted at the river’s mouth, implies a reduction in the percents for depletion upstream, either in Mexico or the U.S.  The amounts left for environmental flows could then be varied by increasing or decreasing the percent for depletion as one moves up or down the river system. It would be magical to think first that anyone would reduce their percent for depletion and then that everyone would agree on where and over what part of any year the reduction in a percent depletion should be applied. It would be slightly less magical to think unreduced percent depletions could be distributed within the Upper Basin, Lower Basin and Mexico to benefit environmental flows, assuming full depletion at the mouth.