10 Apr 2009

My Talk on the Peripheral Canal

Last week, I gave a talk to a class at UC Berkeley. I discussed the politics and economics of the Peripheral Canal.

Although I was doing a lot of work on the chalkboard, I am hoping that most of my points will be clear on the audio I made [23MB MP3]. (Unfortunately, the batteries ran out after one hour and five minutes, but you are sure to get enough material by then.)

You can read this, this and this post to get an idea of what I discussed.

There were two things I was unclear on.

First, how much water is currently exported from the Delta? I know that the CVP and SWP average 10MAFY, but I am guessing that they have been averaging a lot less recently. Is there a site that tracks historical deliveries from these two projects?

Second, how much water does SoCal have from other sources?
  • The LA aqueducts have capacities of 485 + 290 cfs. Given that 1cfs = 724AFY, those aqueducts could deliver 560TAFY, but I think that LA has been getting about half that -- due to the environmental problems in Owens Valley.
  • The Colorado River aqueduct has a capacity of 1.3MAFY and delivers about that much to MWDSDC.
  • The All-American canal has a HUGE capacity (26,155 cfs, nearly 19MAFY -- twice the California aqueduct and the biggest aqueduct in the US), but it can't deliver more than the 3.85MAFY of rights held by the irrigation districts (not including PVID) that use it.
  • The San Joaquin river carries about 1.8MAFY into the area. Friant Dam is one dam that holds back that water.
Besides groundwater recharged by rainfall, am I missing any other major sources of water to the area? Better yet, is there a comprehensive source for those data?

Bottom Line: Southern California CAN subsist -- AND thrive -- on "local" water supplies, but we need to know how much water is there AND have markets to reallocate it.


  1. For years all water agencies and municipalities in CA have been given every opportunity to investigate a non-tributary Source of a million acre feet EACH YEAR that can be developed without damage to the environment or anyone's water rights, anywhere.

    Even with the assurance that the water can be delivered without power;

    can keep Lake Mead reasonably FULL and generating 2000 megawatts of renewable energy in a facility that is already paid for;

    can restore the 2.4B dollar Colorado River Delta;

    and can provide an additional supply when the big earthquake arrives;

    CA simply denies the existence of such a vast natural resource and hopes WaterSource will eventually quietly pass away and take his Source solution with him ...

  2. The San Joaquin River & Friant Dam do not serve Southern California. They are part of the CVP and the water is used to irrigate the Central Valley.

    I guess you could classify the All American Canal as serving Southern California, since the Imperial Valley is in Southern California, but the IV is not served by Delta water (can't get there, anyhow). I have always assumed that you have meant the urban population of Southern California, not including the Imperial Valley.

    (Are you suggesting in your decision that SoCal can live without Delta water, that they somehow make up the difference with water from the Imperial Valley's allocation? They would fight like hell, you know. They have sworn never to agree to anymore transfers.)

    I believe the Owens Valley is delivering just 100,000 acre-feet these days. At least that is what I remember Bill Hasencamp saying at a talk I attended last year.

  3. @Anon -- Yes, I know that IV is not connected to urban SoCal or the south Valley. I am just including them as part of SoCal.

    We're going to need some proper accounting before moving fwd. I KNOW that it's out there somewhere, but I can't find it very easily. (I'll take a look at CALVIN soon; Lund et al. probably have good engineering diagrams...

  4. I can certainly see how the IV can be lumped in with Southern California, although I tend to think of the urban area as separate from the IV as they really have very little in common, and I don't think So Cal & IV 'feel' very connected to one another.

    What I don't get, though, is to lump in the Friant division of the CVP - unless you know something I don't (and since you did dissertate on the MWD, it is a distinct possibility), because to my knowledge, none of that water goes to Southern California, as defined as the area south of the Tehachapi's. At least that is how I would define "Southern California". I certainly wouldn't include the southeast portion of the Central Valley in that geographical description.

  5. The water from the San Joaquin is sent south by the Friant system, and northern California water is imported through the Delta Mendota Canal in exchange. Should exports from the north cease, the historical users of the San Joaquin have first claim. So the answer is both yes and no insofar as to whether the San Joaquin serves southern California.

    The bigger issue is that we have to face two asymmetries that characterize our State. First, for a variety of reasons, primarily related to trade, large populations live in the poorly watered coastal areas. Systems have been built to supply them water. The incremental cost of adding capacity to those systems so that agricultural users could be served made some economic sense, since even at the lower prices farmers pay, amortizing the fixed costs over a much larger volume of water made some degree of sense. More so, when you consider the temper of the times, which favored all sorts of "industrial policy".
    Second, the hydrology of our State means that a very large amount of water is available for capture for a short time; and this is a time when agricultural users have very little use for that water. In addition, the realization that fish and recreation are bona fide beneficial users of water places additional timing and volume mandates that the original designs never contemplated. Hence, we need to develop improvements to our existing systems that address the timing, storage, and delivery of water; and we need to be far more efficient in consuming what we do use. I think North-South exports have to figure in to any solution of this issue, but I won't argue with facts to the contrary.

  6. @Philip -- good points

    @Anon -- I am talking south of Delta...

  7. DW says: Two years ago, I tried to figure out how much was being exported south by the SWP. From what I learned from folks like NRDC and DWR, I believe that up until 2001, the number was 1.5 million acre feet per year or less.

    Then from 2002 -- 2006, Arnold and DWR opened the flood gates and by 2006 more than 6 million AF were moving south the the valley and SoCal.

    Then Judge Wagner became convinced that the SWP export were trashing the Delta, and he has been the key player controlling how much DWR sends south ever since.

    That's why I laugh when Nunez asks that Delta exports be returned to "historic levels". By that I think he means how much was being pumped south in 2006.

  8. I do not think there is any one central place to go. I suggest asking On the Public Record. She is most likely to know, if anyone does.

    1) Delta exports: I suppose you also want to include SF, EBMUD, and the CoCo water districts as well. They each draw water that would otherwise drain into the Delta. There are also several ag water districts (Turlock comes to mind) that likewise pull upstream from the Delta and export it.

    The SWP Delivery Reliability Report has some information about the projects' exports http://baydeltaoffice.water.ca.gov/swpreliability/index.cfm

    The CVP has contracts to divert 3.3 maf annually from the Delta and DWR has contracts for 4.173 maf per year. Even in the wettest years (2006) the projects do not pump that much.

    In total, 4.74 million acre feet (maf) were pumped by the SWP and Central Valley Project (CVP) from the Delta in 2006 (a wet year). The SWP pumped out 3.5 maf and the CVP pumped 2.74 maf. CVP water is not pumped to SoCal.

    SWP delivered 3.5 million acre-feet to agencies South of the Delta
    in 2006. Over 1.9 maf went over the mountains into SoCal (about 54%).
    The rest stayed in the San Joaquin Valley, going largely to the Kern
    County Water Agency (1.3maf).

    I have more links with more info but I've misplaced them. MWD and LADWP have reports they post providing information about their sources. Perhaps I saw some of that info in the water plan http://www.waterplan.water.ca.gov/cwpu2009/index.cfm

    2) SoCal's other sources.

    Do you also include the Central Coast, which also gets some water from the projects.

    L.A. does collect some water locally. For example, several of the San Gabriel Valley cities collect water and then pump it into the aquifers for later use.

    SoCal also has local reservoirs that collect some water from the mountains, albeit not much. A variety of agencies/companies own and operate those reservoirs.


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