On page ix of the Executive Summary, the Little Hoover Commission writes about what the new Department of Water Management would do as an entity. After discussing Integrated Regional Water Management for a bit*, they say (page x):
While the state can help local efforts to change water use, there are some state-level actions which have the potential to produce immense benefits for California as a whole. The state can increase the amount of water available for use and better perform its environmental protection role by managing California’s state and federal reservoirs as a single system, and optimizing their operations to maximize storage. The process would require working with regional groups to integrate groundwater storage into a broader state strategy.
System re-op? System re-operations is the only state-level action that promises benefits worth mentioning? That’s it? That’s what the (new) Department of Water Management can do to make water available for human and environmental use? Oh friends. What this tells us is that THERE IS NO NEW WATER COMING. What we have in the system now is all there is going to be. (Personally, I don’t think we’ll even have that. I think we’ll lose more to climate change and environmental needs than we can squeeze out of system re-op.) Little Hoover Commission listened to all that testimony and heard nothing about the (proposed, new) DWM planning more projects and building new dams, or opening up new sources. The best thing they heard, or at least the only thing they mentioned, was system re-op. Me, I can’t guess what system re-op could yield, but I’d be surprised if it is more than a million acre-feet or so. Not nothing, but it shouldn’t be keeping a whole planning agency busy. Actually, I think system re-op is small enough that it should go with the State Water Project to its new home.
Let’s be clear what system re-op is, conceptually. System re-op is conceding we need new supplies so much that we are willing to incur more risk of flooding. System re-op is being willing to cut into a margin of safety in exchange for more yields. Many reservoirs are run by a historic rule curve that tells the operators how much to empty the reservoir each fall and winter to be ready to catch the season’s floods. That drawdown, that rule about how empty to keep your reservoirs in the winter, can mean lost water. Maybe it can’t be used for irrigation in the Fall and we don’t have a way to put it in groundwater, but we have to release it anyway. The rule curves are decades old. They may be too conservative now; our storm forecasting is better. We could hold on to water until we know for sure that a big storm is coming. Any piece of water that we can keep in a reservoir (when before we would have let it go to make sure the reservoir has space to catch a storm) that’s real, new water. Maybe reservoir re-op is a way of claiming some of the new gains in our knowledge. Keeping the reservoir fuller introduces more risk that we’ll have to pass along a flood, but maybe our better forecasting is enough of a risk buffer to even that out. But maybe storms under climate change will be so much more variable that our old reservoir rule-curves aren’t conservative enough. We don’t know. It looks like we’ll be doing the experiment in real life.
On one hand, the LHC is right. Re-operating the projects is worthwhile, especially operating the big projects conjointly. Adding in flexible groundwater recharge as a place to store those yields will make them even more valuable. But. The fact that we need them, and the implication that they’re the next best option (after integrated regional management, about which I stay skeptical), tells me that we truly do not have any dramatic good next alternatives.