Skip to Content

Desertification as usual:

Groundwater Management Under the Inyo-LA Long Term Water Agreement


The capture of Owens River by the Los Angeles Department of Water and Power (LADWP) in the early 1900s, the consequent drying of Owens Lake, and the destruction of Owens Valley agriculture are relatively well known. Less known is that many groundwater-dependent resources such as springs, wetlands, and thousands of acres of alkali meadows survived the capture relatively intact.

In 1970, LADWP started pumping massive amounts of groundwater to fill its newly- enlarged Aqueduct. Impacts to groundwater-dependent ecosystems were immediate, and Inyo County filed suit under the California Environmental Quality Act. Nineteen years of litigation later, Inyo County and Los Angeles signed the historic Inyo-LA Long Term Water Agreement (LTWA). The LTWA requires that pumping be managed to avoid significant impacts while providing a reliable water supply for Los Angeles.1 Fourteen years of management under the LTWA, unfortunately, raise doubts about the LTWA's effectiveness, and even more doubts about LADWP's good faith in its implementation.

Excessive pumping

In portions of Owens Valley, pumping drawdowns have held water tables below rooting zones of groundwater-dependent vegetation continuously since the LTWA was signed. Field monitoring data and satellite imagery show the drawdowns are causing impacts to groundwater-dependent meadows. The impacts, in the form of lowered cover, loss of perennial grasses, and increases of annual exotic species (i.e. weeds, such as tumbleweed)2 are best described as “desertification.” Hydrologic modeling suggests drawndown water tables are unlikely to recover unless LADWP substantially reduces pumping.3

In the Big Pine wellfield LADWP violated the LTWA's prohibition against groundwater-mining in 2004.4 Under the LTWA, groundwater mining occurs when the volume of the 20 year cumulative annual pumping exceeds the 20 year cumulative estimated annual recharge. The “inherent limitations on pumping” in the LTWA's vegetation protection requirements were supposed to have prevented pumping from ever approaching groundwater mining limits.5 Exceeding the mining limit means that over the last 20 years LADWP pumped more than one drop of water for every drop of water estimated to have recharged the Big Pine aquifer.

Valleywide pumping is also excessive. The USGS estimated the long term average annual volume of pumping consistent with vegetation protection requirements of the LTWA to be about 70,000 af/yr.6 This is based on estimates of vegetation water requirements that may be too low,7 however, so even 70,000 af/yr is probably more pumping than is sustainable. For comparison, during the period from 1970 – 1986 (when LADWP admits pumping impacts occurred), LADWP pumped an average 93,792 af/yr of groundwater. Under current management (1987 to the present), annual pumping has actually increased to average 95,756 af/yr8 and LADWP wants still more!9


When Inyo County challenged LADWP's management in the Laws area in 2001, LADWP denied the existence of pumping impacts by challenging the county's vegetation monitoring protocol. LADWP had agreed to this protocol and accepted its results for the previous nine years. LADWP also argued that any impacts were due to overgrazing by livestock and a proliferation of vehicle tracks. Vegetation cover has generally increased in un-pumped parcels even though livestock grazing and vehicle use occur there as well as in pumping-affected parcels.10

When Inyo County challenged LADWP's 2001–2002 pumping program, LADWP acknowledged no obligation to avoid pumping impacts at all. It acknowledged, instead, an obligation to mitigate after the fact.11 The EIR to the LTWA states repeatedly that impact avoidance is a “primary goal” of the LTWA while mitigation after the fact is “secondary.”12

LADWP makes impacted parcels (noted above) disappear by averaging.13 The LTWA's vegetation protection goals are expressed in units of homogeneous vegetation called “parcels.” In 2001 LADWP unilaterally decided to assess conditions by averaging vegetation cover values for arbitrary groups of parcels instead of examining parcels individually.14 High cover values in some parcels cancel out low cover values of impacted parcels. By analyzing data averaged to a coarse, ecologically meaningless scale, LADWP never acknowledges impacted parcels exist.

Finally, LADWP explains overpumping and its impacts by misrepresenting the basic hydrology of the valley. In the arid climate of the Eastern Sierra, annual fluctuations in runoff (which translate to fluctuations of aquifer recharge) are often extreme. Before massive pumping began, however, these fluctuations had little immediate impact on water tables on the valley floor because large springs, surface water bodies, and vegetation served to buffer water tables.15 Historic data show little correlation south of the Poverty Hills between slight annual changes in water table elevation and enormous annual changes in runoff and recharge.16 In 1970, however, LADWP initiated massive pumping, dried up springs, killed vegetation,17 and thereby eliminated the buffer to water tables under large areas of the valley floor. Changes in water tables are now correlated with annual runoff and, to an even greater extent, annual pumping. LADWP claims this is “natural.” It makes the unqualified assertion that water tables decline “naturally” in low-runoff years18 thereby implying “dry years” are responsible for vegetation declines. Instead of acknowledging the conversion from a buffered to an unbuffered system to be a pumping impact on a grand scale, LADWP claims there are “disagreements between scientists over what the impact of the groundwater pumping is versus the natural change just in the hydrologic cycle.”19 (italics added)

What is to be done?

Inyo County is considering initiating another LTWA Dispute Resolution proceeding regarding groundwater pumping and other complaints. This, however, will be expensive and will probably lead to litigation which is even more expensive. Inyo County has limited financial resources, and, as LA Board of Water and Power Commissioner Dominic Rubalcava has thoughtfully pointed out, LADWP's litigation budget alone exceeds Inyo County's entire annual budget.20

Enforcement of the LTWA depends, in the long run, not on litigation, but upon LADWP abandoning its cynical, exploitative management and implementing the LTWA in good faith. We in Owens Valley can document and attempt to publicize LADWP's abuses, but reform of the agency will only occur as a result of political pressure in Southern California.

If you know voters in Los Angeles and/or LADWP ratepayers, please ask them to contact LADWP and their representatives on the Los Angeles City Council. To learn more about LADWP's continued abuse of Owens Valley, visit and


  1. City of Los Angeles Department of Water and Power and County of Inyo. 1990. Water from the Owens Valley to supply the second Los Angeles aqueduct 1970 to 1990, 1990 onward pursuant to a long term groundwater management plan. Draft Environmental Impact Report. SCH#89080705. (Cited below as “LADWP. 1990. DEIR”).

    Acreages of groundwater-dependent vegetation are given on pp. 10-12 – 10-19. Goals of the LTWA are summarized on pp. S-5 – S-6.

  2. Manning, S.J. 2004. Status of re-inventoried vegetation parcels according to the Drought Recovery Policy, 2003. Inyo County Water Department. May 26, 2004. pp. 22-23. (Cited below as “Manning. 2004. Status Report.”)

    Manning identifies 26 parcels with unrecovered water tables and impacted vegetation. Not all vegetation parcels are monitored, however, so the total number of impacted parcels is unknown.

    Elmore, A.J., J.F. Mustard, and S.J. Manning. 2003. Regional patterns of plant community response to changes in water: Owens Valley, California. Ecological Applications, 13(2): 443-460.

    Rossi, D. 2004. Big Pine falling victim to too much groundwater loss. Letters to the Editor. Inyo Register. May 27, 2004.

    Rossi attributes death of locust trees to groundwater pumping. While his observations are anecdotal, it is entirely likely that some Owens Valley trees have been impacted by drawdowns. Because the required monitoring of stands of willows and cottonwoods (LADWP. 1990. DEIR pg. S-6) has never been conducted, however, it is unlikely there will be data to support attribution of tree deaths to drawdowns. Some of the most visible apparent pumping impacts are thus the least likely to be acknowledged, much less mitigated.

  3. Steinwand, A. and R. Harrington. 2003. Simulation of water table fluctuations at permanent monitoring sites to evaluate groundwater pumping. Inyo County Water Department. February 25, 2003.

    Simulations in this study showed chances of water table recovery to rooting zones (as explicitly required in the EIR to the LTWA) at most monitoring sites are virtually nil with current volumes of pumping.

  4. James, G. 2004. Letter to Gene Coufal. Groundwater pumping from the Big Pine wellfield and the Laws wellfield. November 8, 2004. Released by Inyo County Water Department.

  5. City of Los Angeles Department of Water and Power and County of Inyo. 1990. Water from the Owens Valley to supply the second Los Angeles aqueduct 1970 to 1990, 1990 onward pursuant to a long term groundwater management plan. Draft Environmental Impact Report. SCH#89080705. Response to comments. Vol I. pg. 2-23. (cited below as “LADWP. 1991. Response to Comments”)

  6. Danskin, W.R. 1998. Evaluation of the hydrologic system and selected water-management alternatives in the Owens Valley, California. US Geological Survey Water-Supply Paper 2370-H. pg. 2. (Cited below as “Danskin. 1998. Hydrologic Evaluation.”)

    Danskin gives a figure of 75,000 af/yr which includes flows from artesian wells. When these flows are decremented, the total sustainable pumping comes to around 70,000 af/yr.

  7. Steinwand, Aaron. 2000. The effects of Kc and Green Book models for vegetation water requirements on permanent monitoring site On/Off status. Report submitted to the Inyo/LA Technical Group. April 24, 2000.

  8. Los Angeles Department of Water and Power. 2004. Annual Owens Valley operations plan for runoff year 2004-2005. pg. 3-2, Figure 9, bottom panel in: Los Angeles Department of Water and Power annual Owens Valley report 2004-05 runoff year. (cited below as “LADWP. 2004. Operations plan.”).

    While the EIR to the LTWA was not complete until 1991, LADWP began cooperative management with Inyo County in the mid-1980s, as mentioned by Jerry Gewe in the interview cited in note #19 below. LADWP thus averages its pumping into periods from 1970-1986 and 1987 through the present.

  9. Kelly, W.J. 2004. Money in the lake. LA Weekly, April 30 – May 6, 2004.

    In this article, Jerry Gewe is reported to have already told the LA Board of Water and Power Commissioners that he hopes to pump more water in Owens Valley. The article also discloses the connection between LADWP's excessive pumping of central Owens Valley and its obligation to provide water to abate dust on Owens Lake.

  10. On October 13, 2001 Inyo County initiated a Dispute Resolution proceeding based on the need to avoid impacts to vegetation at Laws and LADWP's refusal to run the McNally canals according to historic practice. Arguments cited in the body of this article come from the legal documents pertaining to this dispute. Legal documents are available from the Inyo County Water Department. Data regarding cover in un-pumped vegetation parcels are in Manning. 2004. Status Report.

  11. City of Los Angeles Department of Water and Power. 2001. Reply to Inyo County Water Department Comments Dated May 18, 2001 and Transmittal Letter Dated May 2, 2001. Document submitted to Inyo County Water Department. June 1, 2001. pg. 2.

    LADWP wrote: “In short, the Agreement requires the City to consider impacts of its groundwater pumping before implementing the annual plan, but does not authorize Inyo to restrict or limit the City's pumping before the fact. The Agreement instead sets forth the method of determining after the fact whether an impact to vegetation has occurred which is measurable, significant, and attributable to groundwater pumping.” (italics added). Note that the LTWA's requirement to “avoid” impacts is reduced by LADWP to a requirement to merely “consider” impacts. LADWP has never publicly explained how keeping water tables permanently below rooting zones of groundwater-dependent vegetation is consistent with its requirement to avoid significant impacts.

  12. LADWP. 1990. DEIR. pp. S-6, 10-70. LADWP. 1991. Response to Comments. Vol I. pp. 2-58, 2-69.

  13. LADWP. 2004. Operations plan. Pg 3-2, Figure 9, third panel down; pp 3-13 – 3-18.

    In the discussion of vegetation conditions in this document the word “parcel” is not used. The “wellfield” averages presented in the report are irreproducible results. They cannot be independently calculated because neither the parcel data nor the wellfield boundaries upon which averages were based are specified.

  14. Los Angeles Department of Water and Power. 2001. Drought Recovery Policy Evaluation Report. April, 2002. Brochure mailed to Inyo County residents.

    The brochure contains a summary of findings in Montgomery Watson Harza's 2001 Drought recovery policy evaluation report, available at The brochure also gives average vegetation cover values for undefined areas called “wellfields”. As in note #13 above, wellfield boundaries are not specified, nor are the parcels included in the wellfield averaging which makes independent analysis and verification of results impossible.

  15. Danskin. 1998. Hydrologic Evaluation. pg. 137.
  16. Lee, Charles H. 1912. An intensive study of the water resources of a part of Owens Valley, California. Water Supply Paper 294. Department of the Interior United States Geological Survey. Government Printing Office, Washington, DC. Lee gives water table data for 1909-1912, before massive pumping began. There were pulses of pumping in the 1920s and early 1930s, but LADWP's records indicate there was no pumping from 1936 through 1959. Some test wells were monitored throughout this period and data from these wells, in conjunction with Lee's, are the best quantitative data for examining “natural” subsurface hydrology.

  17. LADWP 1990. DEIR. pp. 9-35 – 9-36 and 10-54 – 10-76.
  18. Los Angeles Department of Water and Power. 2001. Annual Owens Valley operation plan, 2001-2002 runoff year. May 9, 2001. pg 1.

  19. Metro Investment Report. 2004. LADWP's Water Guru, Gerald Gewe Opines On Owens Valley, Water Marketing & Desal. January 2004 edition. ition_id=2&format=html.

    Gewe's responses to the first and second interview questions are masterpieces of spin. In a few sentences he gives the impression that “third parties” i.e. environmental groups are preventing LADWP from implementing mitigation measures. He also invokes both the “dry years” and the “natural variation” excuses for excessive pumping. LADWP's success in getting the public to focus on “dry years” (instead of pumping-induced draining of hydrologic buffers) is illustrated in the Kelley article cited in note #9. In Kelly's article, Inyo County Water Department Director Greg James and other valley residents are reported to have said that vegetation is dead “because the water table drops below the roots of plants and trees in dry years.” (italics added)

  20. Rubalcava's boast was reported by Inyo County Water Department Director Greg James at the October 8, 2001 meeting of the Inyo County Water Commission.