Sat, 18 Mar 2017 12:51 UTC
Many low-lying areas that were exposed when the lake level was declining during the drought will be inundated with water. The docks will be bobbing in crystal blue waters once again.
Straddling the California - Nevada border, Tahoe is the sixth largest lake in the United States, an outdoor playground for people around the world, and the main water source for the Reno-Sparks, Nevada, area. The renowned ecological wonder is fed by 63 tributaries that drain 505 square miles known as the Lake Tahoe Watershed. With a vast surface area of 191 square miles, Tahoe requires an immense amount of water to fill, especially because roughly 100 billion gallons of water evaporates annually.
Lake Tahoe's natural rim is at 6,223 feet above sea level. The lake can store an additional 6.1 feet in its reservoir and climbs up to 6,229 feet at full capacity, its legal maximum limit. The only outlet, a dam at Tahoe City, regulates the upper 6.1 feet above the low water mark, and this winter water is being released into the Truckee River as billions of gallons flow into the lake.
Tahoe's water level reached 6,226.84 feet on Wednesday, and the lake needs some 88 billion gallons of water to jump up the 2.26 feet required to be completely full. That's the equivalent of filling more than 133,000 Olympic-size swimming pools.
"We feel really good right now," said U.S. District Court Water Master Chad Blanchard. "We're releasing 500 cubic feet of water per second, and trying to manage the elevation. The elevation has been flat for a couple weeks, but we don't want to get too high because we have two-and-a-quarter feet of room. But we could still have as much as four to five feet of water to come into the lake in next five months. It's a balancing act. We have to fill, but we don't want to overfill. And the forecasts we get are just forecasts. They're not perfect."
If Tahoe reaches full capacity, as Blanchard expects the lake will do at the end of July, it would see its largest physical rise in recorded history going back to 1900.
Since the start of the rainy season on October 1, the lake level has shot up 4.5 feet. If the lake fills, it will rise a total of 6.5 feet, beating the 1995 record when it jumped up six feet in a single season, which runs Oct. 1 to Sept. 30.
This is a huge milestone for a body of water that flirted with record-low levels amid a five-year drought. At the same time last year, the lake level was a full 4.19 feet lower. This was discouraging in an El Niño year when storms expected to bring record-breaking snow and rain delivered only average precipitation, filling some reservoirs but making only a small dent in California's drought conditions overall.
And then there's the Sierra Nevada snowpack. The range is piled high with the most snow it has seen in decades, and a recent survey on March 1 indicated the snowpack is 185 percent of average. As the weather warms, this snow will melt and pour billions of gallons of water into the rising lake.
And perhaps the most significant milestone is that the drought will be considered over in the Tahoe area.
"In the Truckee basin, drought is defined as water storage in Lake Tahoe," Blanchard said. "Tahoe is the defining factor. If we're full at Tahoe, the drought is over. Typically, we can get three year's worth of water from the reservoir part. Of course, that could vary in some freak extreme."