Tag: Aqueduct

First Looks: The LADWP 2015 Draft UWMP – Hiding the Shortage

Published / by dcoffin / Leave a Comment

After spending a few weeks paging through the just released LADWP 2015 Draft Urban Water Management Plan, my immediate conclusion is that the plan is a thinly disguised effort to hide the city’s low water supply levels from the planning process to protect development.

This draft, like past UWMP’s, continues to project levels of water in all supply categories that the department does not have access to and it continues to assert access to water in categories that aren’t really a supply such as Conservation and Harvesting.

California law requires that utilities update the UWMP every five years to demonstrate long term water supply availability before approving new projects. This task has become tougher to prove as the regions grow and various interests throughout the state assert their rights to the state’s water supply. The department compounds the problem even further when it reports to planners and developers that there is sufficient water for growth despite the shortage.

In 2010 the LADWP found that totaling up aqueduct, groundwater, recycled water and MWD water was no longer adding up to the total supplies it needed to show as evidence of sufficient growth. To solve this problem, it began to look for new ways to produce water. Some categories were real such as stormwater capture and indirect potable reuse but other categories were simply fuzzy water meant to artificially raise the total supply using paper water.

A Line-by-Line look at the Future Water Supply Projections

The following is a line by line look at the supply projections in the draft's Service Area Reliability Assessments table. I’ll show where the real water is and what’s vulnerable to challenge.


I’m going to be blunt. Conservation is not a supply. Conservation should be used to lower the baseline demand and from there, the department should demonstrate how it will meet that. However, the department uses Conservation as a supply to merely to bump up the total supply figures shown in the Service Area Reliability Assessment tables to present a UWMP that's favorable to planning documents.



The department’s 2015 draft shows Conservation as an existing or planned supply that will contribute up to 125,800 Af/y to the city’s water portfolio. But simply put, this is ‘paper water’.  This is done to hide a portion of the total shortfall the department doesn’t want seen in Environmental Impact Reports that are attached to projects for review by the planning department.

There is a simple test to see if Conservation (or any other category of water) is real water or imaginary water. The 2009 California Water Plan Update describes ‘paper water’ as water that “utilities claim they have access to, but is difficult or impossible to access for various reasons”. 

Using that definition in our test, if we eliminate all of the city’s real incoming sources of water such as the aqueduct, groundwater, recycled water, stormwater, and MWD water, and leave the city with only Conservation, how much water would the city have access to and available to use?

None. The leftover 125,800 AF of 'water' the LADWP claims it has access to is not accessible.  You can’t wash your hands with this water and you cannot sip it from a glass. Consequently, it's paper water and not a supply.

2015CSVPaperAsserting that ‘Conservation’ is a water supply allows the department to manipulate the UWMP's supply projections, making it appear that the city’s total available supply will be 611,800 Af/y in 2020 and grow as high as 675,700 Af/y by the year 2040.

However, when we remove this imaginary water from the table, the departments total projections fall to a dismal 536,370 Af/y and over time it grows to just 600,770 AF/y by 2040. This is would fall more in line with the city’s historical supply.

I’m sure the department sees another benefit to asserting that Conservation is a supply. It doesn’t have to report the actual results like it does with real water from the aqueduct, groundwater, MWD, and recycled water which are all measured as they enter the water system.

Putting Conservation on the supply side of the equation creates a fuzzy math scenario of future water supply that does not belong in documents that rely on the UWMP. The department is basically saying, ‘IF the public reduces it gallons per capita daily by 50%, that’s like increasing the supply to 638,235 AF/y’ or ‘IF the public could meet 100% of the city’s projected conservation level, that would be the same as reaching 675,100 AF/y.

Prior to 2010, the city had always deducted conservation savings from the baseline demand side and calculated the required supply from there. If it did this here, the projections would be in the range of 536,370 to 600,770 AF/y. The department would then have to provide a plan to explain how it will get the city to reduce its per capita supply from 130 gallons per day to just 95 gallons per day.




The next supply item in the planned supply table is the Los Angeles Aqueduct. Sadly, the LADWP no longer finds William Mulholland’s engineering marvel worthy of top billing anymore. Instead it appears that the department wants optics on something called ‘Conservation’ in the UWMP even though that’s not real water like the aqueduct. It’s important to note that the Los Angeles Aqueduct continues to be the city’s largest owned producer of water in the city’s supply portfolio.

2015AquPaper2007This item in the Draft 2015 UWMP uses paper water in the Los Angeles Aqueduct projections to hide 68,030 to 85,730 AF/y of the city’s total supply shortage.

The draft does this by seriously over estimating how much water is available through the aqueduct.

It’s nothing new however. The departments past UWMP’s had projected upwards of 380,000 acre feet of water per year entering the system. This draft cites up to 293,400 Af/y is still far more than the aqueduct’s actual average supply of just 207,670 AF/y between 2007 and 2012.  (To be fair, I’ve purposely excluded the last three years due to the recent drought.)

There is no reason to believe that future aqueduct supplies will average higher than 227,000 Af/y even if the department is able to lower the amount of water needed to mitigate Owens Basin dust levels.




The next major source of water supply and third on the list is Groundwater. Like every UWMP before it, the Draft 2015 UWMP continues citing far more access to groundwater than the department really has access to.

2015GWPaperThis conclusion is made by comparing the actual measured groundwater supply that has averaged just 74,390 AF/y between 2000 and 2015 with the departments Draft 2015 UWMP projections of 112,670 to 114,070 AF/y. Anything more than 74,390 AF/y is paper water which is used to bump up the total supply and hide the departments shortage in planning documents.

From a historical perspective, there is simply no evidence that the department will meet the projections they cite in the current draft. Claims of over 100,000 AF/y have been made in every iteration of the departments UWMP since 1985.

Recycled Water – Irrigation and Industrial

Recycled water is next in the planned supply table in the Draft 2015 UWMP. The department split Recycled water is split between two sub categories back in 2010 and that continues today. They are ‘Irrigation and Industrial Use’ and ‘Groundwater Replenishment’.



Irrigation and Industrial Use, better known as purple pipe is expected to contribute 19,800 AF/y of water into the city water system by 2020 and increase to 45,400 AF/y by 2040. 2015RCYPaperHowever, the departments history of meeting purple pipe projections suggests that they will not come close to meeting these new projections either. Over the last eight years the department’s average has been just ~7,500 AF/y.

EIR’s produced between 2010 and 2015 have all claimed that by 2015, water recycled and distributed through purple pipe would be contributing 20,000 Af/y into the city’s water system.

However, the department missed that mark badly with only ~9,800 AF of measured supply by September of 2015.  Earlier UWMP’s promised even more water, citing that up to 29,000 AF/y would have been available by 2015.

Even given the chance that the LADWP might eke out at least 15,000 AF/y of purple pipe water, the Draft 2015 UWMP is effectively be hiding up to 30,400 AF/y of the city’s total supply shortage using paper water in this particular category.

Recycled Water – Groundwater ReplenishmentRepl


Our fifth line of the planned supply table is Groundwater Replenishment. This is not expected to begin contributing the city’s water portfolio until 2025. Groundwater Replenishment is a treated wastewater program known as Indirect Potable Reuse which is similar to Orange County’s successful IPR program.

If the department is successful at rolling out IPR, this may turn out to be a real supply. How much we actually see entering the system on a year to year basis remains to be seen.

Stormwater Capture – Harvesting

What was new to the 2010 UWMP but considered only a ‘potential supply’, Stormwater Capture has been undeservingly upgraded to a ‘planned supply’. It is split between two line items, Stormwater ‘Reuse’ and Stormwater ‘Recharge’.



Stormwater Reused is the sixth supply line item in the planned supply table. Also known as Capture and Reuse or Harvesting, it is another fuzzy water category consisting of Rain Barrels and Cisterns. The department claims that these components will be contributing to 400 AF/y to the city’s water system by 2020 and that will increase to 2,000 AF/y by 2040.

In the previous 6 years, the 2010 UWMP asserted that Harvesting would contribute 2,000 to 10,000 AF/y of water into the city’s water supply portfolio but none of that was ever reported.

Development projects throughout the city parroted that claim in their EIR’s but the department could never measure it nor report it.

Whether it’s the 2010 UWMP or the 2015 plan, this category fits the definition of paper water because the department has no direct access to it.

Rain barrels and cisterns are back yard, privately owned containers that do not have gages mounted to them that report back to the utility. There is no way the LADWP can tell if they are actually in use, whether they’ve collected rainwater or if they have been repurposed for other uses. I get the sense that they are keeping this category around mainly so that they can give away rain barrels to promote the conservation.  

The Draft 2015 UWMP uses paper water in the Stormwater Reuse category to hide 400 to 2,000 AF/y of the city’s total supply shortage.

(Correction: The graph and analysis in this section incorrectly cited the Single Dry Year table of 100 to 400 AF/y when Average Year Table was meant to be used.  The level of paper water in this section was raised to 400 to 2,000 AF/y - 3/3/2016 dcoffin) 

Stormwater Capture - Recharge


The seventh line item of the UWMP planned supply table is ‘Recharge’.  Over the years the city has relied on ‘natural recharge’ but this has severely decreased due to the city’s urbanization because as structures and roads were built over permeable soil.

The intent is to build an infrastructure that will capture up to 15,000 AF/y of water during intense rainwater events and allow it to infiltrate into to the ground much like natural recharge.

This may very well be another form of supply that is difficult to access given that is relies on rain events. For example, El Nino was thought that it would bring heavy rains to the Los Angeles area in the Winter/Spring of 2016 but that did not happen.

Recharge will be subject to the same meteorological events that groundwater pumping relies on and as noted earlier, groundwater pumping has never met the long term projections found in past UWMPs.  There is no guarantee that it will result in 15,000 Af/y supply until the program is in fully implemented and effects can be measured as it enters the city’s water system.  How much we actually see entering the system on a year to year basis remains to be seen.

MWD Water Purchases with Existing/Planned Supplies


‘MWD Water Purchases’ is an interesting category because the department has consistently ‘underestimated’ how much it will buy from the Metropolitan Water District.  This happens because as previously noted, the LADWP claims it has access to water it doesn’t have access to.  Sooner or later the department has to quietly make adjustments and purchase additional water from the MWD to make up for the shortage.

The 2015 projections are pretty stunning given that it represents a 68% drop from the 2010 UWMP and worse, an 80% drop from the real purchases. 

Given how much paper water is in this draft UWMP which includes the so-called ‘Conservation’, there is no evidence that the LADWP will be able to meet those projections and subsequently limit MWD purchases at this level unless Mayor Garcetti wants to deliberately deepen the city’s water supply shortage by plunging the city into a Phase IV or Phase V restrictions.   

Between 2000 to 2010, the LADWP projected it would be purchasing an average of 247,995 AF/y from the MWD. But during this time the actual average supply it purchased from the MWD during that time was 30% higher at 325,570 AF/y.

This clearly demonstrates that the LADWP has not been meeting its real water projections and that its projections are indeed full of paper water. The department’s MWD projections are simply not reliable.




Over the last six years, projects working their way through the planning process cited in their EIR’s that 40,000 AF/y of Transfer water would be available to the city by 2015 along with other surplus water in the other categories. However, the department was not able to access this water that so we can firmly place this in the category of paper water.

With the water market turning increasingly bleak, the LADWP rightfully did not include Transfers in the Service Area Reliability Assessments table as a ‘Planned Supply’.  Instead it downgraded Transfers to a ‘Potential Supply’ but it still remains on the Service Area Reliability Assessments table making it ‘appear’ as if it is accessible.  

The chances that the department will have access to this water is fairly remote given that there no willing sellers in the Central Valley or Northern California and its like that the department would find itself bidding against the well-financed Metropolitan Water District.  

The $40 million spent by the LADWP on the Neenach Pumping Station Turnout Facility Project in the Antelope Valley doesn’t seem like a great investment today.

MWD Water Purchases with Existing/Planned Supplies and Transfers




The tenth and last item in the Draft 2015 UWMP Services Area Reliability Assessment is an alternative MWD Water Purchase should the LADWP be able to secure contracts for water in the ‘Transfer’ category.  It states that if the LADWP were to be able to secure contracts for 40,000 AF/y of Transfer water, this would result in lower MWD purchases amounting to ~20,630 to 35,430 AF/y.



L.A.’s First Water Plans – The 1985 & 1990 UWMP

Published / by dcoffin / Leave a Comment
In 1983 the State of California passed the Urban Water Management Plan Act that required water suppliers to provide a water plan every five years. 1985UWMPCoverThe Urban Water Management Plan (UWMP) is rich in information as it identifies the agencies sources of water (aqueduct, groundwater, imported), amounts of water available from these sources, methods of conveyance, current and future water uses, projected demand, current and future conservation methods, demographics, population density and growth, housing mix, commercial/industrial/governmental demand, etc. The importance of the UWMP is that it is used as a guideline for making public decisions concerning water and is cited in planning documents, water supply assessments. But the UWMP can also be seriously misused when 'paper water' is inserted into the plans which provides a misleading assessment of the water supply or when city officials simply rubber stamp the findings without any sort of reassessment given current water supply availability. The City of L.A.'s UWMP's are both fascinating and disappointing in that they paint a picture of great expectations, a long term failure to meet demand and worse, a misleading assessment of the city's true water supply. What follows is a retrospective look back at previous UWMP's. What we find is a blueprint to a permanent water deficit. The 1985 UWMP - L.A.'s First Water Plan
Figure 1
The 1985 UWMP was the first state mandated water plan published by LADWP. This first time report was an honest and useful assessment of the city's water supply at the time. The plan assumed the city would receive a constant 470,000 Af/y supply through the Los Angeles aqueduct, 103,000 Af/y of groundwater and a small but growing reliance on MWD water between 1986 through 2010. From a planning perspective the most important part of the UWMP are the tables that show the projected water requirements at 5, 10, 15, and 20 increments for average years. The tables break down how much water the city assumes it will receive through the aqueduct, local groundwater, MWD, and recycled water. It's important that these projections meet the actual supply 5, 10, 15, and 20 years later because they are used in environmental impact reports and water supply assessments as guidelines for future development. If the actual supply doesn't meet the projections then we can assume we are creating a water supply deficit. (more…)

LA Aqueduct on Google Earth

Published / by dcoffin / 5 Comments on LA Aqueduct on Google Earth
lasimpleFor those of you interested in seeing the LA Aqueduct up close on Google Earth. Download the LA Aqueduct KML in the library on the right and open it in Google Earth. This a pared down version of my more complete KML but it still has a lot of stuff to explore. Over the next few weeks I'll upload my other KML's including the Colorado River Aqueduct, SWP, Hetch Hetchy, Mokelumne, San Diego aqueducts, etc.

L.A.’s Losing Access to Water

Published / by dcoffin / Leave a Comment

This is Part II of a series describing L.A.’s water supply problems and the policies that produced it.

As remarkable as L.A.'s water supply growth was in its first 75 years, city's residents would be stunned by the loss of supply since 1985 if they were aware of it. For awhile optimism crept into the water plans and the city thought that there was no limits to growing since it could continue to rely on its appropriative rights and relatively constant 1984 levels for future growth. In 1984 the city's supply reached 716,915 af with the Los Angeles Aqueduct supplying 74% of the total supply and there really wasn't any reason to believe that it couldn't continue to maintain these levels far into the future.

L.A.'s Losing Supply - Post 1984
L.A.'s Losing Supply - Post 1984

However things began to unravel in a big way. While the city would continue to supply water ranging from 650,000 to 701,000 af/y for the next few years,  this was coming as aqueduct levels were falling dramatically and the city was increasingly relying on Metropolitan Water District supply.

L.A. would soon be learning that water in California is a zero sum game and where there are winners, there are always losers. For the first 75 years L.A. was the winner and the people of the Owens and Mono Basins were the losers. Outside of a few episodes of farmers and towns people dynamiting sections of the aqueduct in the early years, exports to L.A. were relatively low key until the Second Los Angeles Aqueduct came in to service. The modest 300,000 af/y imports through the first aqueduct might have continued to this day had the second aqueduct not been built. But in 1971, the second barrel changed all that and it took export levels to an entirely new level.

In three short years the flows through the aqueduct increased 73 percent from 343,767 af to 471,304 af. Exports from Mono, once restricted to 123 cfs by the capacity of the First aqueduct downstream, could now export waters from Rush and Lee Vining Creeks at its full 400 cfs capacity. By 1979 the aqueduct system was delivering over 500,000 af/y using both barrels to Los Angeles.

But the Second aqueduct upset a delicate balance. Entire creek flows on Rush and Lee Vining were diverted. Little water was passing by the diversion gates into the lower creeks and into Mono Lake. The creeks dried up and so was Mono Lake. Similarly 120 miles south, groundwater levels in the Owens Basin was falling dramatically and unable to support native plants and turning the basin into the most dust polluted region in the United States.

Once unnoticed, now people were taking notice. For the first time, L.A.’s aqueducts imports were threatening the health of areas where the waters came from. It was one thing to take water away from farmers or local townspeople. The city argued, they sold their rights fair and square. However it was an entirely different matter, to destroy creeks, rivers, lakes and produce dangerous levels of dust. The lawsuits began to fly and the courts found another rights was in peril, the ‘public trust’. Public trust and CEQA would trump the city’s ‘appropriative right’ and what followed would bring aqueduct exports back to 1940's levels. But the damage was already done.

L.A.’s first bow shock came in 1972 when the County of Inyo filed suit under the California Environmental Quality Act. The court of appeals later limited the city's pumping to 148 cu ft/sec thus losing about 107,000 af/y. In 1983 'Public Trust' mandated reconsideration of LADWP creek diversions and diversions on Mono Lake.

Los Angeles began losing access to water. The magnitude of the loses were huge. Today, 60% of the city's aqueduct supply is devoted to mitigating the environmental damage that the Second Aqueduct started. What follows is a summary of the actions that resulted in the city's loss of access to water.

Mono Basin Litigations

  • 1983 (Audubon v Superior Court) ‘Public trust’ mandated reconsideration of LADWP diversions and the diversions on Mono Lake.
  • 1985 (Dalgren v Los Angeles) – Court finds ‘public trust’ requires release of 19 cfs down Rush Creek to protect fisheries.
  • 1987 – (Mono Lake Committee v City of Los Angeles) Court finds ‘public trust’ requires release of 4-5 cfs down Lee Vining Creek to protect fish habitat.
  • 1989 (California Trout v SWRCB; Caltrout I) – State Water Resource Control Board was in violation of Fish and Game Code by failing to establish ‘bypass requirements’ at LADWP diversion in Mono Basin.
  • 1990 (California Trout v Superior Court; Caltrout II) – Court directed SWRCB to exercise it duty to amend LADWP Mono stream water rights to release sufficient water to re-establish and maintain fisheries that existed before the diversions.

These cases were coordinated (packaged as one) as ‘Mono Lake Water Right Cases’ in El Dorado Superior Court. The net result of this collection of cases was that the court ordered LADWP to release 60,000AF of water down Mono Lake tributaries. In 1991 the same court found that 60,000AF was not sufficient to maintain Mono Lake levels and set permanent stream flows limiting exports from Mono Basin to 4,500AF per year to raise and maintain level of Mono Lake to 6,377 ft above sea level.


   Loss: > 60,000AF

Owens Basin Litigation

  • 1973 – County of Inyo v. Yorty, California environmental Quality Act applies to Owens Valley pumping.
  • 1973-1984 Groundwater is restricted to 149 cfs.
  • 1987 – EPA finds Owens Valley in ‘non-attainment of particulate (dust) matter.
  • 1999 – (Great Basin Air Pollution Control District v. Los Angeles) - To meet PM-10 standards, LADWP to divert ~90,000 AF to Owens Lake to control dust.
  • 2007 – Lower Owens River Project (LORP) A written understanding between Inyo County, California Department of Fish and Game, the State Lands Commission, the Sierra Club, the Owens Valley Committee and the LADWP to release 40 cfs (30,000AF) into Lower Owens River to mitigate pumping in the Owens Valley.

   Loss: > 90,000AF

Metropolitan Water District

The City of Los Angeles isn't the only client agency of the MWD. The MWD serves 25 other agencies representing all of Southern California. Since 1984 the city has increasingly lost access to aqueduct water and depended more on the MWD.  Whereas 74% of the city's supply came from the aqueduct in 1984, today the MWD supplies the city with ~75 percent of its water.

However growth, the drought and environmental litigation have taken a toll on the MWD as well. Allocations from the State Water Project allocations were drastically curtailed in 2007 with a federal court decision to reduce pumping. Over the last five years have been reduced to just 39% and in the last two years to just 13%. Metropolitan states that with just 930,000 af of Colorado River deliveries and 382,000 af of SWP water, it will be forced to make significant withdrawals from the Southland’s remaining reserves to help meet water demands. Metropolitan's reserves have fallen to 50% of what they were in 2012.

In October of 2014, Mayor Eric Garcetti issued an executive order to reduce the city's reliance on MWD water by 50%. While he did not state it I don't think there should be much doubt that the city's decision to reduce MWD purchases is related to MWD's own supply challenges.

   Loss: > 200,000AF


Recommended reading: ‘Owens Valley Revisited’ (2007) by Gary D. Libecap which focuses on the original negotiations between the Eaton, the city and Owens Valley farmers between 1905 and 1938 and the environmental litigations that took place from 1983 to the present.

L.A.’s Growing Access to Water

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This is Part I of a series describing L.A.’s water supply problem and the policies that produced it. To summarize the city’s first 75 years of access to water with one word that word would be ‘remarkable’. During that period The City of Los Angeles saw its access to water supply grow from 51,402 to 716,951 acre-feet per year by 1984. Acquiring that growth of supply took luck, engineering, tenacity, foresight, bold investments, deception, exploitation, dishonesty, and friends in high places to make it happen. The following is a summary of the main water projects that brought water to the City of Los Angeles in order of time completed. The numbers below are close but inexact because the data came from various agencies and they did not always compare and earlier data is quite old so this became a challenge for me to try and summarize. However they were close and are accurate enough to develop a picture of an extraordinary period of water supply growth that enabled the city to grow from 577,000 people in 1920 to 3.9 million today. Los Angeles River
L.A.'s Growing Supply
L.A.'s Growing Supply - 1913 to 1984
In 1887 the city waterworks was only a series of ditches, pipes, and ferris wheel like contraptions that plucked water out of the Los Angeles River. The slow moving 71 cu ft/sec flows of water in the Los Angeles River clearly limited the city’s growth. With only 51,000 af/y of water available to the city and recognizing that the Los Angeles City Water Company lacked the means and desire to develop new sources, the city council of Los Angeles directed the city engineer Fred Eaton to draw up plans to acquire the private waterworks and create a municipal waterworks. Along with the acquisition, the city also acquired a pivotal figure in the development of the city's future water supply, the company’s superintendent, William Mulholland. Mulholland immediately expanded the use of water meters in the city to extend supplies but he asserted that the city could not grow beyond 220,000 people without more water. To grow, the city would need to find new sources of water outside of the city. Mulholland surveyed potential sources of water at Piru Creek, Kern, Santa Ana, Mojave, and San Luis Rey rivers but eventually ruled them all out. Separately, Eaton had been traveling the Owens Valley and had seen a pair of private surveys that determined that it should be technically possible to construct a canal to bring the waters of the Owens Valley to Los Angeles. Eaton and Mulholland began promoting the idea and soon Eaton had the role as the city’s agent to buy up Owens Valley properties for the water rights. Over time the Los Angeles river no longer served as a viable source of water. Instead as the city grew and development overtook open land and agriculture the rivers only purpose would be a means to channel storm water and treated waste water into the ocean. LA Aqueduct (Completed 1913) In response to Mulholland's warning that the L.A. River was incapable of supporting more than 220,000 people, L.A. City voters approved a series of bonds to purchase Owens Valley properties and begin construction of the aqueduct. Construction on the 235 mile long aqueduct began in 1908 and was completed in November of 1913. The aqueduct had a capacity of 486 cu ft/sec or about 352,000 af/y and for the first time, the city was receiving a reliable supply of water that would average about 216,000 af/y per year. Local Groundwater Groundwater supply for the city of Los Angeles from 1916 through 1958 averaged about 56,360 af/y per year which increased L.A. Supply to an average 270,000 af/y. Mono Extension (Completed 1941)
control gorge194188pr1
Control Gorge - Mono Extension.
Library of Congress HAER CA-298-K-6
With a rapidly growing population the city passed another bond in 1930 to extend the aqueduct up the Mono Basin and capture waters from Rush Creek and Lee Vining Creek. The Mono Extension was completed in 1940 with diversions beginning the following year. While the Mono extension had a capacity of 400 cfs,  exports were limited to 128 cfs because the aqueduct downstream had finally reached it's capacity. The city for the time being would have sufficient supplies once it began receiving Colorado River water the following year. Along with pumping in the Owens Valley, the aqueducts flows increased L.A.’s supply to an average of 314,000 af/y. Metropolitan Water District – Colorado River Aqueduct (Completed 1941) As a member agency of the Metropolitan Water District the city is permitted to buy water from the MWD. The Colorado River Aqueduct was completed in 1941. Los Angeles buys imported water from the Metropolitan Water District at a higher cost than city owned water. Between 1941 and 1984 CRA supplies to L.A. averaged 45,000 af and along with increased local groundwater pumping together they would eventually push L.A.’s total supply to an average of 448,000 af/y. Second Los Angeles Aqueduct (Completed 1970)
2nd Aqueduct Construction at Terminal Hill.
Construction of 2nd Aqueduct
at Terminal Hill.
The aqueduct’s 422 cubic foot/second capacity was not enough to meet the 590,000 af/y the city was licensed for and this bottleneck became an issue when the State Department of Water Resources reported in 1956 that the city was only exporting 320,000 af/y. In 1959 the DWR told the city it would lose its rights to the water it was permitted for if it did not appropriate it. Faced with this possible loss, the city then began construction of the Second Los Angeles aqueduct in 1965 and completed it in 1970. The aqueduct added 290 cu ft/s capacity and mostly paralleled the first aqueduct until it reaches the Antelope Valley where it take shorter route across the valley floor. Both 1st and 2nd aqueducts join together at the Elizabeth Tunnel complex and separate again at the south end of the complex. In 1974 the city received licenses to divert up to 167,000 af/y annually from Mono and Owens pumping would add 160,000 af/y. Second Los Angeles Aqueduct increased L.A.’s supply to an average of 591,000 af/y per year. Metropolitan Water District – State Water Project (Completed 1971) The State of California completed construction of the California Aqueduct in 1971. The California Aqueduct delivers waters from the Sacramento Delta to Southern California. As a member agency of the Metropolitan Water District, the City of Los Angeles has access to SWP imports. L.A.’s supply peaked in 1984 at 716,951 af/y. NoLimits As the supply grew it seemed that there was no limits to the city’s growth. But water in California is a zero-sum game. In Part II I'll describe the loss of access that will take L.A.'s city owned supply back to pre-1940's levels. storyend_dingbat Recommended reading: ‘Water and Power’ (1982) by William L. Kahrl which tells L.A.'s water story from the beginning in 1885 through the mid eighties and ‘Owens Valley Revisited’ (2007) by Gary D. Libecap which focuses on the original negotiations between the Eaton, the city and Owens Valley farmers between 1905 and 1938 and the litigations that took place after the publication of Kahrl's book.