Wednesday, September 23, 2015

Current water policies, not water, limits California population growth

I hear from people with no particular expertise in California water issues that we can't have people keeping on moving to our state, especially to the part of the state where those people live.


And I think that's right, iff we keep the same policies and same current water use patterns. That iff could well be right, changing policies is hard. OTOH, here are three facts:

About 20-25% of California water use is urban, where the vast majority of people live and where the overwhelming majority of population increases are occurring. A majority of that urban water use is for landscaping, either residential or commercial. We could virtually eliminate that use and supplement landscaping with graywater, allowing us to double the urban population with no increase in potable water demand. And if virtually eliminating lawns isn't politically feasible, see point 3.

About 75-80% of water use is agricultural, creating about 2% of California economy. At the simplest level then (okay, simplistic), reducing ag water use by 25% would also allow doubling California's urban population while costing 0.5% of the economic output. Hopefully the farming community will be aware of this and encourage innovative ways to conserve water in both urban and agricultural areas. The economic and political risk is obvious.

Recycled non-potable water, recycled water for drinking, shallow aquifers for non-potable use, and desal of brackish groundwater are all new urban water options that limit the pressure for #2 and the severity of #1. That's not even including ocean desal, which I think is mostly a bad idea, but if we are truly in the worst-case scenario of a 100-year drought then even that could play a role.

Summary:  other developed countries like Australia and Israel have shown compatibility with far lower per-capita water use, and we've got additional technological options for water.

Behind this, I'll lay my own biases on the table:  the US has chosen to support policies for a lot of population growth in this country, with a lot more people having American-sized ecological footprints. Not my choice, but given that, I think California is a good place to put a lot of those people, at least in the Bay Area and coastal SoCal where most of the people will go.* We have a smaller ecological footprint here, and our policies other than the egregiously-bad tax policies are pretty good, so why not here. And it's a nice place.

So that bias might color my conclusion, but the opposite bias is in place for many people who've said water is the reason why things shouldn't change from what they remember things to be.



*Also far north California, Redding and west to the coast where there's lots of water, but few people will end up there. It's in Sacramento and points south and east that you see more typically-destructive patterns of urban growth. Some growth will happen there, but that's not where most people will end up

13 comments:

Dano said...

This bunny moved away from Sacto in 2003 & was peripherally involved in water politics there. The one point I'd make is about the greywater for irrigation. What we're finding in Colo is the alkaline soils and scant rainfall work on greywater and soil in such a way as to allow for the buildup of salts in the soil, and right now you can see the effect on coniferous trees across the Front Range in places using greywater.

Not sure we know what the answer is, and maybe there is a cutoff point there from, say, Stockton north where greywater would work, but south of that not enough annual rainfall to flush salts. Other issues as well with older housing stock and need to keep trees (or retrofit with higher R-values in walls and roof), also dairy in San Joaquin Valley being large water users who maybe can go.

Other thing I'd say is the management/political will isn't there to manage so many people well - the carrying capacity for that place is much less than current population now, and will get worse here in the coming decades as climate change bites down hard on Sierra forests and snowpack.

.02

Best,

D

John said...

Cutting a mere 0.5% off the rather small (2%) contribution of agriculture to the states GDP actually cuts 25% of the food supply to CA and many other states.

Thanks for the lesson in facile economic analysis that so often misses the vital issues at hand.

John Puma

DaveE said...

Does the average reader know that iff means "if and only if"?

Brian said...

Hi Dano - I'd guess that almost anywhere can take some graywater, the question is how much until rainy season/snowmelt can't stop soil buildup.

One thing I tell people with this concern is to not use washwater from the washing machine, just the rinsewater. Some day someone will design a washing machine with a programming switch for this.

Planting a graywater/recycled-water compatible landscape sure would help. I got that put into the San Jose General Plan in 2012, although I think it's been mostly ignored.

Redwood trees are terrible on this, and people keep planting them where they don't belong (any place that's not a fog belt).

John - I guess we'll just have to shoulder on while eating less alfafa and cotton.

Nigel Franks said...

If you cut back on meat and dairy consumption, you can cut agricultural production significantly without starving people.

Fernando Leanme said...

One way to slow down population growth is to stop illegal inmigration. This requires a better designed LEGAL inmigration program, say like Canada's. With regards to water use I would discourage rice using conventional methods and seeds. Growing rice causes harmful methane emissions.

Kevin O'Neill said...

Fernando - how does illegal immigration increase population growth? Do you have any science to back this up?

On the face of it, it justs shifts population from one country to another - though some die in the process of trying to get to their new country - so it may actually decrease population, not increase it.

The question should be more on the lines of why is it illegal for people to move from one country to another? Capitol easily moves where ever it wants, labor not so much. Make all immigration legal and VOILA!, illegal immigration eradicated.

Statists, racists, and nationalists seem to always have a problem with this idea though.

Dano said...

Brian, I get it, and retrofits will be scarce. And I totally agree on the redwoods, as I lived in Sacto and watched them die as they approached 45-50 ft tall.

Best,

D

Hank Roberts said...

> far north California, Redding and west to the coast
> where there's lots of water, but few people will end up there

Dunno abou that. The four-lane-divided highway has pushed north past Willits, the commuter railroad is being revived, and the timber companies that own most of the NW part of the state continue to try to fiddle the laws to let them finish the most profitable logging opportunities then turn the area over to the real estate developers instead of replanting it in trees. That latter -- which requires changing tax breaks that have let them keep logging with the presumption the'd replant -- is one of those battles that has been going on for decades that I'm aware of.

All they need is a little change in the weather, a little less fog overall down around the SF Bay area -- and New Suburbia will happen there.

Call me cynical.


Oh, on redwoods -- single ones die. Forests comb moisture out of the air, as I recall. That's why they didn't come back after the logging in so many areas, and why El Palo Alto has those pipes to keep the humidity high enough for it to survive all alone. (That's the tall tree that was visible to the sailors after they came through the Golden Gate standing out above the others far to the south)

Cynthia said...

California is in serious need of a "Box of Rain":

https://www.youtube.com/watch?v=V4SqDx1vi4c

Brian said...

My theory on El Palo Alto is that it's also a planted redwood tree - only the planting was 1000 years ago. And this was the one redwood planted in the right place - alongside a creek that flows half of the year and at the beginning of the perched shallow aquifer that keeps groundwater near the surface.

It was fine until we started paving and putting a railroad bridge right next to it.

James Cliborn said...

Hank Roberts: Roger that and to make things worse the areas west of Redding all the way to the ocean have been experiencing drought-like conditions too for the last ten years or so.

Russell Seitz said...

Dano:

google bright water seitz and tell me what you think