This project is being implemented for the purpose of assessing mitigation potential at sites throughout the Owens Valley. Surface and ground water diversion and extraction from the Owens Valley has resulted in impacts to springs, wetlands, and riparian areas. The ecosystems of Owens Valley support several listed species, many rare species, and other potentially sensitive species for which accurate range and population data remain uncertain. Among the listed species are federally endangered Owens pupfish (Cyprinodon radiosus
) and Owens tui-chub (Siphateles bicolor snyderi
), and California threatened Fish Slough milk-vetch (Astragalus lentiginosus
) and endangered Owens Valley checkerbloom (Sidalcea covillei
). Stakeholders have allocated 1,600 AFY for the purpose of mitigation at Hines Spring and other additional mitigation sites. The purpose of this project is to present an analysis of mitigation potential at Hines Spring and other on-site and off-site mitigation locations. The assessment provides the information necessary for stakeholders to decide which potential mitigation sites should receive additional assessment and further analysis, and which sites require the development of mitigation plans. This project provides an opportunity for habit enhancement and restoration throughout the Owens Valley.
Mitigation at Hines Spring would be implemented for the purpose of re-establishing spring, spring channel, marsh, and alkali meadow habitat types that have declined due to the effects of ground water extraction. A trench was excavated at the former Hines Spring source area and samples were collected for C-14 dating, palynological analysis, and fish and invertebrate remains in order to complete a historical analysis of flora and fauna previously located at Hines Spring. The feasibility analysis of mitigation at Hines Spring included the assessment of a range of flows and methods of water delivery, the use of surface vs. ground water sources for mitigation, different types of fish barriers, habitat suitability requirements for target species, and hydraulic modeling of the recommended restored spring channel.