Dam Upgrade Project - See pictures below

This Lake is owned by PG&E. Normally the Lake fills in the late spring from snow melt. While the final fill level varies year to year it generally fills to near full or within 2-3 feet of full and the Lake remains at this level for most of the summer, until Labor Day. PG&E does start to generate power during the last 2 weeks in August. Over the last few years the date generation is started has been delayed to provide a higher water level.

The Dam at Bass Lake has been identified as one that needs to be upgraded to meet modern seismic standards. PG&E has been working on performing an upgrade for several years. Originally this upgrade would have no affect on Lake level during the summer with only a slightly lower level in the winter. On March 4th, 2009 PG&E announced along with the Federal Energy Regulatory Commission and the State Division of Safety of Dams, the Lake would not be allowed to fill above -10 feet from full until the upgrade is completed. The completion of the work is expected by Spring 2013. This level would be about 4 feet below a low water year that we had in the summer of 2007. At the completion of the job, the top soil at the quarry site will be replaced and trees replanted.

So what does this mean. Some private dock owners and a few community dock will be challenged with low water levels. All 3 Marinas will be operational. For docks that are affected, PG&E will work with dock owners to make adjustments if possible so those docks can be usable. For most people it will have no affect. The Lake will still have plenty of water to boat, ski, fish and swim.  The Lake will have great sandy beaches.

Construction Update September 15, 2012
Work is progressing in head of schedule by about 41 days. The Construction on the Dam will be completed by the end of 2012. Normal water levels will return for the summer of 2013. Work will continue in the area for the next year as the quarry and other areas are returned to a natural state.

Construction update April 5, 2012
The down stream side is finished. Crews have started to dredge the upstream side and lay rock. The water level is increasing at a rate to match last year by June 1st.

Construction update February 28, 2012
PG&E wll allow the Lake to start filling late this week, 2 weeks before prior estimates. With some Rain we hope to see the Lake fill to the same level as last year.

Construction update February 18, 2012
The Bass Lake seismic upgrade to the Dam has reached a new phase of construction. On February 14th PG&E received a Fish & Game permit that allows them to start work on the Lake side of the Dam. This winter the Lake's water level was brought down to a extra low level to allow for excavation of the base of the Dam on the Lake side. Rock will be placed at the base and tied into the bedrock. Once this critical initial work is completed the Lake will be allowed to fill. PG&E has stated they will allow the Lake to start filling mid March. In my opinion this is good news. I have been tracking Lake levels for 10 years. You can see the numbers at my web site, Even with below normal rain and snow the Lake should fill by Memorial Day weekend to the minus 10 ft restriction during construction. This is the same level as the past 3 years. PG&E has told me this is a priority to get this work completed. They will be working extra hours to complete this phase.

Construction update August 19, 2011
The Quarry has provided an insufficient amount of the right type of rock. Additional rock will be brought from the Raymond Quarry. That means trucking it in. We could see up to 32 round trip truck loads of rock over the next few months. The trucks will travel along Knowles Road (416), Raymond Road (415), Spinelli Road (416), Highway 41, North Fork Road (200), Crane Valley Road (426) and Highland Drive (222). Additional space is needed to store unusable rock and dirt so there is a pending request to enlarge quarry for storage. The time table for the completion of the Dam is by Spring 2013.

Construction Update May 5, 2011
Our heavy spring rain and snow storm prohibited crews from excavating the footing of the dam as planed in March. This has caused a 3 month delay. The estimated time for completion is now Mid June 2012. This also means the Lake will not be allowed to fill above the restricted minus 10 level in the summer of 2012.

Construction update Jan 29, 2011
Quarry Blasting will comence on Feb 2, 2011. The Public is prohibited from entering areas within 1000ft. Flagmen will stop traffic on Rd 222 during blasting. 5 minutes before the blast occures will be a one minute series of long horn signals. 1 minute prior to the blast will be series of short horn signals. Following the blast will be one prolong horn signal indicating the blasting is complete. Blasting will be limited to a few days per week.

Construction update Nov 4th 2010
PG&E has received nearly all the permits needed for the project. The First stage has begun, clearing trees over the quarry site. Next week they will start drilling dewatering wells to lower the water table below the Dam. Once completed, in about March of 2011 they will begin to excavate below the Dam to expose bedrock and begin to add rock foundation. This part will take about 1 month. This winter the Lake level will be lowered to -28 feet, about 4 feet lower than normal.

The pictures below were taken on 11-18-10. The quarry site is being prepaired and a test well is being drilled. They will remove about 30 ft of top soil to expose the rock below. The whole area is closed to the public and is monitored by security. The public boat ramp and its associated parking are unaffected. The extra parking at the Dam is closed.

Click on the image for a larger view

For further information you may visit the PG&E website