Really excellent points, John! You don't build reservoirs to capture 100-year or 50-year rainfall events. You build them to capture excess flows from above average years to use in below average years or to capture average flows and allow outflow on your schedule rather than the schedule nature provides. Dams are built with the 50-year and 100-year returning flows in mind, but from safety considerations, not sizing or siting consideration.
When we talk about CA water usage issues, most of the transfer is internal to CA, with Imperial Valley/SoCal coast being the exception, though CA would argue that the usage was established with canals off the Colorado, which forms the eastern border of So.Cal, making it an internal flow and not an out of basin transfer. Likewise, Utah, CO, WY, and NM have out of basin transfers that they would consider as integral to the water rights of the respective states. AZ and NV water all returns to the CO river drainage, though lower than we might like.
Additionally, the IPP was constructed where it is in Utah to take advantage of area coal mines, not as an outsource for pollution (though that was also an advantage). Iit is cheaper to connect a power line to an demand area than to ship all the coal necessary for power generation. Utah provided a generous tax break for IPP as well to provide Delta with some good jobs and to provide Utah coal mines with a good market. IPP will be switching power sources, which will provide even more jobs for Delta, though the coal mines won't be as lucky (though I understand IPP was switching from Utah sources anyway).
Back on topic, the whole point of a MS to LP pipeline would be additional supply to the lake. Unless demand upstream and downstream of LP is reduced or additional supply (natural or piped in) is brought onboard, we will see continued depletion. So my idea if we want to preserve Powell:
- Upstream demands must be frozen... No more upper basin diversion projects. What you have right now is what you will get unless there is a big shift in supply to the system that shows long-term sustainability
- Lower basin needs to identify alternate sources to bring into the system. This will include reuse in CA, desalination in CA, desalination in MX and AZ. Pumping up to these areas will max out at 1200 ft and doesn't have nearly the issue to contend with that a MS to LP pipeline would have. Desalination will only cover municipal uses though, since it is too expensive for agriculture volume
- Offset CO trans basin diversion with pipeline from MO/MS rivers to cover KS & NB flow demands. CO captures more of the Arkansas and Platte Rivers and significantly reduces transfers CO River water to front range.
- Enhance Imperial Valley and Arizona irrigation systems. Subsidize change over in exchange for reduction in water rights. This will require eminent domain actions in cases.
- All will be funded by new tax on water consumption in the area. Agricultural users, industrial, users, and municipal users will all incur a new CO river transfer tax in proportion to consumption.
I haven't run numbers but should make available 2-4 MAF annually in the system.