Gem Dam Cabin Project

Distributed on behalf of SCE. Please contact SCE for details as listed below.

The Gem Lake Dam Cabin Construction Project has been approved by USFS/FERC and is anticipated to begin Monday, September 25th. The initial scope of work (4-6 weeks) has been significantly reduced to approximately 1 - 1.5 weeks with a drastic reduction in total number of flights. The project description is described below and in the attached flyer. A project hotline has also been established for public inquiries at 760.376.8050; SCEeasternsierra@sce.com.

SCE has reserved the June Lake Community Center on November 9th to provide an update on the Rush Creek Relicensing process. Details to follow.

Gem Lake Cabin Project:

Purpose – The Gem Lake operator’s cabin positioned at the base of Gem Lake Dam sustained severe damage over the winter due to heavy snow loading. After structural evaluations from operations and SCE engineering it was determined that the cabin roof will, at a bare minimum, need to be replaced. SCE is working on the long-term plan that will be executed in 2024 to replace the roof. In the interim, the structure will need to be stabilized to ensure public and personnel safety as well as the integrity of the dam operations equipment. The cabin currently houses critical dam monitoring equipment that is at risk if the structure were to fall over, or water is allowed to enter the area where the electronics are housed. Gem Lake is currently operated under a storage restriction from both state and federal dam safety regulators due to seismic concerns with the dam. The equipment located within the Gem cabin is critical to maintaining compliance with these restrictions as it provides information for water management decisions as well as control for the outlets used to release water. If the equipment is not protected before Winter 2023, SCE may be unable to respond to the Spring 2024 runoff which could create unsafe hazards, as the site may not be safely accessed until snowmelt has progressed, greatly shortening the period of time available to manage the flows. SCE has developed an interim protection plan to temporarily secure the roof section and protect the dam monitoring equipment over this coming winter.

Duration and Timing – The project is expected to be one week (7 working days) commencing on Sept 25th and concluding the first week of October 2023, to complete the construction. SCE will work 10-hours a day, Monday-Friday, during daylight hours.

Air Support – In addition to the cabin, the tram system between the Rush Creek powerhouse and Agnew Lake, sustained similar snow load impacts and is currently inoperable. This condition coupled with the already out of service Gem tram required a careful evaluation concerning transport of personnel and equipment to the work location. Contact with the local pack station revealed that their operations are already heavily supporting the relicensing crew and full camp support is not available for this work. Furthermore, any transportation in and out daily on horseback or foot is time prohibitive and will not allow for ample working time to complete this work as scheduled. Air support is needed for transportation due to the short construction window and 10-hour workday. After careful consideration of project support needs, being mindful of keeping flights to a minimum, SCE is efficiently managing the total number of flights (≈36-40) by flying personnel and loads on each leg of the flight. Helicopters will be staged at Rush Creek Powerhouse and will not fly before 08:00 and will shut down by sunset Monday through Friday. External loads will not be flown over the trails.

Hat Ridge LZ Safety - Public safety is a priority for the SCE Gem Cabin project. A Monitor will be located at Hat Ridge during helicopter passenger flights and ensure Hikers, the Pack Train and animals are clear of the landing zone (LZ). The SCE Monitor will communicate with the Pilot utilizing an Edison radio.