Even though the rainy season was a good one for California, it really doesn’t change San Diego’s supply picture or our near-complete reliance on water imported from hundreds of miles away through pipelines and canals. It’s good that San Diego’s residents are becoming increasingly aware of the precarious position we’re in and have responded positively, although sometimes relatively small accomplishments are overblown with hyperbole and politics. We’ll briefly look at that and then I have a few suggestions for what should come next.

941 two-bedroom market-style apartments under construction a few years ago near Naval Station San Diego

The San Diego City Council recently approved an ordinance that requires new apartment developments to have a separate water meter for each unit. Councilmember Marti Emerald’s press release calls the initiative “cutting edge” and boasts that San Diego is “setting the standard for water conservation in our region and the rest of the state.”

I wonder if she knows that Santa Monica passed a similar ordinance ten years ago. Anyway, the new measure only applies to new apartment construction, not existing structures, and even with new construction, high-rise apartment buildings are exempt from the submetering requirement.

Meanwhile, Councilmember Donna Frye worries that with mostly good news about the state’s water reserves, San Diegans will quickly revert to more wasteful ways, so she wants to make San Diego’s water restrictions permanent. The San Diego Water Department and Mayor Sanders are opposed to that idea, though, partly because the city’s policy would be at odds with the policies of the other county water agencies where the restrictions are temporary, which would lead city residents to complain about being singled out.

The San Diego Union-Tribune jumped on Frye’s bandwagon saying:

“San Diego County has two main sources of water, the Colorado River and Northern California. Supplies from the Colorado are not likely to increase much in coming years. Our water future lies in Northern California, more storage capacity, more desalination plants and conservation…. Voters in Northern California will have to be convinced that residents of Southern California are doing everything we can to conserve…”

[i.e., in order to garner northerners' support for the $11.1 billion state water bond to finance local and regional water projects]

First, Colorado supplies “not likely to increase much” is a bit off the mark: the truth is that we were taking more Colorado River water than we had rights to and we can’t do that anymore (it belongs to Arizona and Nevada). If anything, we can expect even more reductions from the Colorado. Plus, take a look at this chart showing the river’s supply vs. demand:

Contrary to conventional wisdom, it is increased demand causing our shortages, not drought.

Second, implying that we’ll take even more water from Northern California (and suggesting we should keep conserving in order to counter objections from the north) is hardly the message we want to be sending. The signal we should send is that we’re well aware we shouldn’t be taking more than we already are, although we do need to do something to defend against a catastrophic cutoff of the existing flow due to delta levee failures from an earthquake and/or salt water intrusion from rising sea levels.

The editorial correctly observes that storage capacity, desalination, and conservation are important and indeed, we’re making progress there: we’re more than doubling the capacity of San Vicente Reservoir, the Poseidon Desalination project is proceeding, and we’re doing a fair job of conserving water and should definitely go on conserving.

That brings us to two things we hear very little about.

1. Water pricing to reward conservation and penalize waste. San Diego ought to enact a water rate structure modeled after the one used at the Irvine Ranch Water District. Their rate structure defines a typical household’s size and water needs with a water budget. Price tiers are: low-volume, base rate, inefficient, excessive, and wasteful. Prices are graduated to penalize use above the estimated household need. There’s flexibility, too. If one’s household holds more people than average and requires more water than the standard model provides, one can apply for a variance to accommodate the extra need and avoid being penalized.

For some reason, this idea of water budgets with pricing incentives has been resisted by city officials and unless we put some pressure on, they’re likely to continue avoiding the issue.

2. Indirect Potable Reuse (IPR). In my opinion, IPR has the potential to provide San Diego with a tremendous amount of “new” water, although at present it is only being contemplated as supplying a small fraction of our water needs. San Diego is currently setting up a study to determine whether IPR can be used to augment our water supplies.

IPR is usually defined as the augmentation of a drinking water source (surface water or groundwater) with recycled water, followed by an environmental buffer that precedes normal drinking water treatment.

Alvarado Water Treatment Plant at Lake Murray

In San Diego’s IPR study (also referred to as Reservoir Augmentation Demonstration Project), basically it is to determine the feasibility of taking recycled water and purifying it with highly advanced treatment. This treated water would then be blended with raw water coming in from the Colorado River and Northern California and stored at San Vicente Reservoir to age for a specified period of time. Incidentally, the purified recycled water would actually be of better quality than the imported raw water in which it is blended! Next, as is done now with imported raw water in San Vicente, the blended water would eventually go for drinking water treatment at a plant such as the Alvarado Water Treatment Plant at Lake Murray.

During the IPR study, 1 million gallons per day (MGD) will be produced. If the study proves IPR is feasible and if the city council and mayor ultimately approve an IPR reservoir augmentation plan, 16 MGD would be produced, according to Eric Symons, Public Information Officer from the San Diego Water Department.

How much water is that? Consider that irrigating Balboa Park requires around 1.5 million gallons per day.

Personally, I think even 16 MGD is too modest a goal. We should be thinking at least 50 MGD…for starters. Over the long term, IPR opens the possibility to very significant amounts of water, limited only by how much we use in the first place!

Unfortunately, there is a public perception problem. Some people have taken to using the terms “Toilet-To-Tap” or “Purified Sewage” to refer to water produced through the Indirect Potable Reuse (IPR) process. These not only sound disparaging, they also obscure the extra processes which IPR represents.

To summarize: wastewater (or sewage) is treated to tertiary recycled water standards. IPR then puts that tertiary water through advanced treatment for purification and disinfection.

A 2007 city study found that IPR water quality was equal to or better than the imported raw water stored in our reservoirs. That water then goes to a potable water treatment plant like Alvarado.

Still, the public perception problem is only that: perception. Consider: Las Vegas and other communities along the Colorado River empty their treated wastewater into the river (one of our imported sources), so it would be correct to say that we’re now doing unintentional or unplanned indirect potable reuse — without the benefit of additional treatment. The planned indirect potable reuse program being studied gives water more treatment and more rigorous quality control than our current water gets. If you look at it that way, it’s actually strange that people would react so negatively to the idea of planned IPR to augment our supplies.

So, how about some support, Councilmembers Frye and Emerald? With a smart water pricing policy and expansion of the reservoir augmentation program beyond 16 MGD, we might just offset the effects of reduced deliveries of imported water.