The Environmental Impact Report (EIR) pertaining to the second Los Angeles aqueduct identified land that had become barren due to changes in surface or groundwater management (City of Los Angeles Department of Water and Power and County of Inyo 1990). These lands have either remained barren for at least 20 years or the current plant cover and composition is dominated by weedy annuals. The mitigation identified in the EIR for these lands requires revegetation with native perennial plants. Because the success of revegetation on barren lands in the Owens Valley is largely unknown, the EIR provides the opportunity for Inyo and Los Angeles to conduct studies to develop effective techniques. A Memorandum of Understanding (MOU) which accompanies the EIR and long-term water agreement requires revegetation plans and implementation schedules to be completed by June 13, 1998.

The MOU states that the plans “will be prepared in accordance with the procedures set forth in …the Green Book,” the technical appendix to the Inyo-Los Angeles Agreement (City of Los Angeles Department of Water and Power and County of Inyo 1990). These procedures include: establishing a goal consistent with the goals and principles of the long-term agreement; consideration of feasible alternatives to mitigate the impact site such as cessation of pumping and use of surface water; revegetation using native plant species; and implementation of measures to control weeds and fugitive dust. The Green Book also calls for an annual written report to the Inyo/Los Angeles Standing Committee containing monitoring results and a description of the effectiveness of the mitigation program in achieving its goals.

As a first step towards understanding the research needs and existing techniques that could be employed for revegetation in the Owens Valley, a literature search was conducted in 1993 focusing on arid lands (Yamashita 1993). Currently several revegetation studies have been initiated in the Owens Valley. One study that began in 1991 consisted of planting containerized native plants in Laws and subjecting them to different planting densities, irrigation, fertilizer, and weeding regimes. Later a seeding trial was also conducted at the site (Yamashita and Manning 1997). Additional studies have tested protecting naturally occurring seedlings (Yamashita 1997) and transplants with plant shelters. Results from the Owens Valley studies, information gained from the literature search and restoration conferences, and collaboration with others working on arid land restoration were used to develop the mitigation plans included in this report.

This report describes project goals, monitoring, and general revegetation methods that will be employed at the various sites. A site description is provided for each mitigation area which includes the site location, environmental setting, soil description, quantified goals, site priority, revegetation plan, and species anticipated for use. The general site evaluation was conducted in 1993-1994 and 1997. These evaluations involved delineating the EIR-mapped sites on aerial photos and then visiting them to note areal extent and current conditions. Sites were categorized as they were in the EIR according to type of impact, either abandoned agriculture (ABAG), groundwater pumping, or into a third category of “potential” sites that “will be considered…for selective mitigation” by the Inyo/Los Angeles Standing Committee. The latter are all within the Laws wellfield and have been impacted by a number of water and land management activities such as groundwater pumping, abandoned agriculture, water spreading, and grazing.

Four additional sites have also been included under “potential sites” in case the stated mitigation goals change to incorporate native plant revegetation. Two of these are slated for “re-greening.” One is an undefined potential enhancement/mitigation (E/M) project that will become a native plant site if permanent irrigation is infeasible (East Big Pine), and another may be converted to alfalfa “if the natural vegetation does not increase”(East Shepherd Creek). These sites are briefly described here, except no on-site mapping, species list, and quantified goals were developed. It is assumed that the initial work on the ABAG and pumping impacted sites will increase the effectiveness of revegetation on these potential sites should the need arise.

It is recommended that all sites be protected as soon as possible. Other recommendations presented in this report will initially be tested in small plots to evaluate their effectiveness and to refine techniques. The most effective methods will then be applied over a larger portion of the site.

The Standing Committee may consider amending this plan if an area covered by the plan is proposed for uses other than revegetation. Proposed uses other than revegetation may include community or Indian reservation expansion or changes in land use such as conversion to irrigation. Any amendment to this plan that would result in uses other than revegetation would be subject to compliance with applicable requirements of the California Environmental Quality Act and with any provisions in the 1991 Final EIR pertaining to modification of mitigation measures adopted in the EIR.

Common names for plants were used in this report. Scientific names can be found in Appendix I, Species List.

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