Tuolumne Utilities District has just announced that the Phoenix Lake Preservation and Restoration project is nearing completion.
Last summer, over 160,000 cubic yards of sediment were removed from the reservoir. If that volume of sediment were to be placed on a football field, it would reach a height of nearly 100 feet.
Many portions of the lake’s bottom have been deepened and new channels were constructed to give the lake a new form and enhanced function.
The improvements will reduce the growth of prolific invasive aquatic vegetation while improving water quality, cold water habitat for fish, and for use as a domestic water supply.
Most importantly, the sediment capture basin on the north side of the lake is now complete and operational.
Absent the new sediment capture basin, sediment would continue to be broadcast throughout the lake and, over time, accumulate until the lake deteriorates to its former condition. The basin is critical to the on-going preservation of the lake.
Access to the eastern portion of the lake (East Pool) was hampered by wet conditions and soil types that made dewatering and conventional excavation impractical.
To remove sediment in this area, a wet based hydraulic or mechanical dredging operation would need to be employed. Unfortunately, the cost to “wet” dredge greatly exceeds the District’s remaining budget.