Key Facts / FAQs

What type of dam construction makes up the Crane Valley Dam?

Crane Valley Dam consists of two distinct dams separated by a rock knoll. The Main Dam is location in the main channel of the creek, and has earth fill on the upstream side of the core wall and rock fill on the downstream side. The West Dam is located adjacent to the main dam in a smaller side channel west of the creek, and has earth fill on both sides of the core wall. The spillway is located on a saddle about 500 feet to the east of the dam.

What are the seismic improvements being made to the Crane Valley Dam?

In summary, the seismic retrofit project will include the following measures:

  • Installation of rockfill buttresses on the sections of the dam that have hydraulic fill on both the upstream and downstream sides of the concrete core wall
  • Tying back the top of the concrete core wall in the section of the dam where the downstream shell consists of a massive rockfill embankment
  • Raising and re-grading the crest to elevation 3387, about 7 feet above present minimum crest elevation, to provide more freeboard
Will parts of the lake be closed off during the retrofit construction?

During parts of construction it is expected that an area by the dam will be closed. However, this work is scheduled to be completed during normal drawdown of the reservoir and should not have an impact to recreation in the summer months.

Will local roads be closed during the seismic retrofit construction?

In order to safely and efficiently transport material and equipment to and from the construction site, a traffic control plan will be developed in accordance with conditions required by the Madera County Road Department and other resource agencies. Road safety signs will be installed and flag persons will be used in accordance with traffic control best management practices (BMP). Along with public warning signs, temporary chain link fencing with gates will be installed at both ends of the dam.

What government agencies regulate Dam safety?

The California Department of Water Resources, Division of Safety of Dams (DSOD) reviews the stability of dams. In recent years, DSOD has worked with Dam owners to meet new standards based on improved design approaches as well as new findings and requirements regarding earthquake hazards and hydrologic estimates in California.  FERC is also a regulatory agency for PG&E and they also support the retrofit work.

If seismic issues were reviewed in 2002, why is the retrofit project starting now?

DSOD asked PG&E to review the seismic stability of the Crane Valley Dam in 2002. The technical investigation and study of the dam’s stability required time to complete. The analysis from the study indicated a retrofit project was needed. PG&E has since worked with DSOD and FERC as well as other governmental agencies to determine the engineering design and extent of the retrofit needed to achieve the stability requirements. PG&E is working as quickly as possible to secure all needed permits and approvals to begin and complete the retrofit project.

Bass Lake is being required to maintain a water level reduction to 10 feet below maximum water level for safety of downstream residents. Will this restriction be year round or just in the summer months?

As an operating reservoir, Bass Lake water level fluctuates throughout the year and during the winter months is often lower than the level 10 feet below maximum lake level restriction. Hydro generation will continue throughout the construction project and the 10 foot reduction restriction is specific to summer months.

How long will the Bass Lake water level reduction be in place?

The reservoir restriction will remain in place until completion of the dam seismic retrofit estimated to be 2012.

Will homeowners be allowed to move or extend docks to reach the lower water level? What is the approval process for homeowners?

PG&E will work with homeowners to allow extensions and replacement of boat docks where it is safe and feasible. Please contact Dan Clark, Land Planner at 559-263-7385 to coordinate approval process.

Will resort owners be allowed to move or extend docks to reach the lower water level? What is the approval process for resort owners?

PG&E will work with resort owners to allow re-adjustments of facilities where it is safe and feasible. Please contact Dan Clark, Land Planner at 559-263-7385 to coordinate approval process.

Will PG&E reimburse businesses that may be impacted from the lower lake level?

The seismic retrofit of the Crane Valley Dam is essential to the long term stability of the dam as well as safety for the downstream residents. Even with the lower lake level, Bass Lake will remain open for recreation throughout the construction of the project. Bass Lake is an operating reservoir and levels do fluctuate during drought years, dependent on the State’s energy needs, etc. PG&E is not responsible for private businesses along the shorelines. However, PG&E work cooperatively with the local community and through our FERC License to manage recreation as one of the beneficial values of the reservoir.

How will the permit approval process impact the project timeline?

PG&E has continued to meet regularly with the permitting agencies to ensure all requirements for permits are in place once the environmental review is completed. PG&E and the permitting agencies are committed to permitting and completing this project as quickly as possible.

Based on the anticipated completion of the Environmental Impact Report (EIR) process and securing permits, we anticipate starting the project in September 2010 and completing the project in February 2012.

Road to 222 will have traffic control to assist in crossing trucks from the quarry to the dam construction site. Will the Wishon Campground at Miller’s Landing be impacted or closed for recreation?

The Wishon Campground will remain open during construction.

How many employees will the seismic retrofit project employ?

The project will be completed in several phases and the number of employees will vary during different phases. At the project’s highest peak there will be 35 to 40 employees employed.

What could delay the project once the project begins? What is the potential for delay?

There are different requirements under the Endangered Species Act and Migratory Bird Act that may conflict with planned timelines. PG&E will work to complete the construction within the 19 month timeline but there may be factors such as these and weather that could delay the schedule.

What are the impacts to the launch ramp and parking areas at the dam?

The boat launch will be available. Parking at the boat launch will be available. The dam area will be closed for construction activities and parking will not be available at this location.

Why is the lake level restriction still in place when construction has not started?

The lake level restriction was not put in place to facilitate construction. The lake level restriction was put in place to reduce the risk of downstream flooding due to a seismic event. The Division of Safety Dams (DSOD) and Federal Energy Regulatory Commission (FERC) who regulate the dam determined the lake level reduction necessary to protect public safety and reduce the flood risk in the event of an earthquake. To read more about the lake level restriction go to Bass Lake Level Reduction on this website.

How is air quality being evaluated for the project?

Air quality is being addressed through the environmental review process under NEPA and CEQA as well as the San Joaquin Air Quality District and other permits.

Will the Bass Lake water level be increased back to normal after construction is complete or will increasing the lake level have to wait for the re-vegetation to be completed?

PG&E anticipates the water level will return to normal once construction is completed pending approval by DSOD and FERC.

The USFS is considering a design for the quarry access road and haul route that is located near cabin owners who lease land as tenants on USFS property. Is this road design final and who will make the final decision?

The USFS is still evaluating numerous road designs to access the quarry and a final design has not been chosen. The USFS is accepting public input on the project. Dave Martin, Bass Lake Forest Ranger will make the final decision.

What is included in e-mail notifications?

PG&E has established a website at to provide updated information on the project schedule, construction and public meetings. If you sign up on the website to receive email notifications, when milestones occur on the project, you will receive an email newsletter about the project.

The County has plans to close the fire station near the project during the winter months. How will this impact the project and worker safety and first responder concerns?

PG&E will meet with the County to learn more about their plans.