15 Sep 2009

Data! Data!

Professor Joseph Dellapenna kindly sent this table [pdf] summarizing the different property rights regimes -- Appropriative, Dual (appropriative & riparian), Regulated Riparianism, and Riparian -- for each of the 50 states. Although I know that rights correspond to water scarcity (riparian is more common in wet places; appropriative in dry), I'd be interested to know if the regimes match some measure of water efficiency and if regimes have changed to improve things.

This website (and this one!) provides data on per capita water consumption (perhaps indoor only?), a concept that is very important and often unmeasured. I'd LOVE to see an open access listing of per capita consumption for US cities. Anyone?

Top consumption award (as reported) goes to UAE, at 500 liters/capita/day. Canada comes in at 326 lcd, then the US at 295 lcd. According to the other site, the US leads at 575 lcd, so that's probably indoor and outdoor.

Bottom Line: Property rights can drive water use, and measurement of water use is critical to understanding how well water is managed. No rights, no management; no measurement, no management.


  1. Can someone give me a definition of 'consumption'?

    From a physics point of view, the following cases appear to be different.

    1. lawn sprinkler - some of the water evaporates and is lost to the local system.
    2. Pouring coffee down the sink or emptying a washing machine into the local sewer system-this water is recycled locally and often reappears in the watering of municipal sites.
    3. Pouring a coke on the ground - the local water in the coke slowly seeps into the ground water.

    Example 1 is lost to the local system (consumed?). Example 2 is recycled in the local system (not consumed?). Example 3 is retained in the local system but unavailable for a while (???).


  2. @DZ: Not sure where to get city level water use data, but the USGS compiles data at the county level every 5 years. < http://water.usgs.gov/watuse/ >
    This is broken down into surface and groundwater use and further into use sector, i.e. ag, power, domestic, commercial, etc. Some of it is also broken into total vs. consumptive use.
    I've used this data set a number of times, including for a research paper I did while in law school looking at comparative rates of groundwater water pumpage for irrigation in a set of counties along the border between New Mexico (prior appropriation) and Texas (rule of capture). The paper was designed to tease out effects of the differing property regimes governing access to groundwater in each state. Results were about as expected - lots more groundwater pumped under rule of capture in TX - but there seemed to be some rather surprising efficiency implications. I can send you a copy of the paper if you're interested.

  3. BTW, he has PA wrong - or it at least should have it included in footnote 5.

  4. Eric - I think you need to consider the source of the water when you look at consumption.

    If your water source is surface waters then I would think that in most cases your 3 examples are non-consumptive uses (though in example 3 the water in the coke might be considered consumptive if the coke isn't bottled locally).

    However, if the water is coming from ground water it may be consumptive as the water often times can't be replaced for hundreds if not thousands of years (i.e. the system has a very slow recharge rate).

  5. David
    Regarding the "policy gap" in San Diego, Donna Frye's statement is meaningless within the framework of the coercive monopoly that is our water supply system. As an economist you must be aware that without competition there is no way to establish the true cost or price for any service. Water is no different. Unless we eliminate government barriers to uncoerced trading in water we will never be able to rationalize the supply and demand for water. We will always be at the mercy of some bureacrat/politician.

  6. Not too bright16 Sep 2009, 02:50:00

    David...am I missing the link to the pdf file? Can you post it a bit more clearly for those of us too slow to see the link?

  7. not too bright16 Sep 2009, 02:52:00

    nevermind...must have been my computer settings...

  8. @CB -- please *do* send the paper.

    @Efinancial -- IMO, it's impossible to have a "free" market in muni water (yes for wholesale/ag water), so we have to deal wit hbureaucratic pricing. All I say is raise the price (some for free, pay for more) until quantity demanded falls to meet supply. That's a good enough efficiency outcome for me :)

    @n-t-b -- I forgot the link on the original post. You're not crazy (and you're computer is not to blame :)


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