Lake Kaweah is on the rise

Every year, it’s unknown if and when the Lake Kaweah basin will reach its highest level. Sometimes it occurs in May but in above average snowpack years, when the warmest weather comes a little later, that highwater mark will occur in June or even early July.

“We’re subject to the whims of Mother Nature around here and we’ll take whatever she gives us because we have no choice,” said Phil Deffenbaugh, Lake Kaweah’s general manager.

Long-range weather forecasts indicated early in the current season that the fabulous February, which brought tons of snow to the Sierra Nevada followed by below average temperatures in March, indicated the peak storage at Lake Kaweah would be a June event.

Now that the warmer temperatures have arrived, a level that Deffenbaugh describes as “full but not full” has occurred. The pre-2004 basin (145,000 cfs) means that during that degree of full, water will have entered the fuse gates on Terminus Dam but still has 40,000 more acre-feet to reach the spillway at the top.

The 15-day weather forecast calls for cooler temperatures with some rainfall, but then a return to a steady climb back to the upper 80s that will sustain the snowmelt and the flows of the Kaweah River tributaries at a mean inflow between 2,000 and 3,000 cfs.

Typically, a run of triple-digit temperatures is required to melt all that snow so past fill events usually occurred in early to mid-June. Last year (2017-18), when precipitation was below normal, the basin never filled to capacity but reached its high-water mark at 175,660 acre-feet on May 27. Full capacity at the spillway elevation of 715 feet above mean sea level is 185,550 acre-feet.

Current storage in the gradually filling basin (May 9) is 147,084 acre-feet; inflow is 2,685 cfs.; outflow is 1,742 cfs. Pool elevation is 696.14 amsl.

The reality of climate change is that when it’s warm in Three Rivers (at 1,000 feet amsl), it can be a similar temperature at 7,000 to 8,000 feet. In other words, it’s getting warmer at higher elevations and, likewise, snow levels are moving higher too.

Even with the current conditions and four different computer models, it remains uncertain on what day the Kaweah River will reach peak flow. On Saturday, April 27, the peak flow for spring in the Middle Fork reached 3,500 cfs.

On Thursday, May 9, Horse Creek Campground and Kaweah Recreation Area boat ramp (boat ramp no. 2) were closed due to high water.

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