Hot Creek and the Upper Owens River are two of the most productive and popular trout fisheries in California. Hot Creek, which flows into the Upper Owens, is essentially dependent on two sources of water: natural headspring flow and Mammoth Creek. Mammoth Creek serves as the predominant runoff conduit for Hot Creek and plays a critical role by providing vital sediment transport and flushing flows in the late spring and early summer. These flows enable Hot Creek to maintain viable and self sustaining wild trout populations throughout the year. Unfortunately, Mammoth Creek also serves as the primary source of surface water for the Mammoth Water District.

In an attempt to protect the riparian community and aquatic resources of Mammoth Creek, the United States Forest Service instituted minimum instream flow requirements in 1977, preventing over-appropriation by the District.

However, during the late 1980's and early 1990's the State Water Resources Control Board (SWRCB) issued temporary permits allowing the District to divert more water from Mammoth Creek during dry years. In 1996, a Mono Superior Court decision granted an additional interim flow schedule to Mammoth Creek and again allowed the District to reduce Mammoth Creek's minimum instream flows. This 1996 interim flow schedule was scheduled to become permanent only after the completion of a comprehensive and satisfactory Environmental Impact Report (EIR) documenting all potential impacts to the watershed. The District currently operates under the 1996 revised minimum instream flow schedule but is yet to produce a final EIR.

Drafts released in 1997 and 2000 were met with significant public comments from California Trout, the Department of Fish and Game, SWRCB, Los Angeles Department of Water and Power, the Sierra Nevada Aquatic Research Lab, and the Hot Creek Ranch. Several of the comments focused on: the need for reasonable water type year flow proposals; the potential that Mammoth Creek was fully appropriated; groundwater pumping impacts to Mammoth Creek and Hot Creek and other water demand reduction techniques that were not adequately considered in the draft EIR. Although the District made some progress in documenting impacts to Mammoth Creek and monitoring those fish populations, several issues and potential impacts to the lower watershed were not adequately addressed. Specifically, the District did not examine impacts from a revised minimum instream flow schedule to either Hot Creek or the Upper Owens River. Considering the connectivity of the watershed and the vital role that Mammoth Creek plays with spring runoff and sediment flushing flows for Hot Creek, CalTrout and others felt it was imperative that the EIR document impacts to these sections of the watershed as well.

After an inadequate response to comments from the 2000 draft EIR, CalTrout filed a legal petition to the SWRCB requesting relief on December 9th, 2004. The petition outlined several specific goals, including: (1) a completed final EIR for the District's revised minimum instream flow program, as mandated by the California Environmental Quality Act (CEQA); (2) SWRCB closure on permanent fishery protection measures for Mammoth and Hot Creek which identify measurable success criteria and adaptive management; (3) identification of additional studies needed to assess revised minimum instream flow impacts to Hot Creek; and (4) identification of other demand reduction techniques, including stringent water conservation policy, that help maintain the region's ecological integrity while also meeting the Town's increasing water demand.

Caltrout would prefer to work with the District to reach a settlement on instream flows for Mammoth Creek, rather than litigate. Under such an agreement, Caltrout would work closely with the District, the SWRCB, Department of Fish and Game, and other parties to determine additional studies and monitoring activities needed to complete the final Mammoth Creek EIR. However, if negotiations stall, Caltrout will immediately request a hearing before the SWRCB.

In the initial meeting after the petition was filed, the District indicated that they would like to complete the final EIR as scheduled. Furthermore, the District stated that they would prefer to pursue collaboration and examine potential impacts to the lower watershed, including Hot Creek, from a revised minimum instream flow regime. Caltrout is optimistic that this is a step in the right direction. We will continue to protect the ecological integrity of the Upper Owens River watershed and the economic stimulus that it provides to those in the Eastern Sierra.

 
VIEW COMMENTS ON THE NOTICE OF PREPARATION FOR THE MAMMOTH CREEK ENVIRONMENTAL IMPACT REPORT