Lake Shasta and other large reservoirs in California have been losing billions of gallons of water.
The area has seen some of the worst heat waves on record, and water managers are startled by the massive amounts of water evaporating from the lakes.
The lake’s water level dropped by 288.8 million gallons on July 3. Water evaporated at a rate of 3,392 cubic feet per second, equivalent to over 2.2 billion gallons, in the first nine days of July.
Shasta Dam’s area manager, Don Bader, of the United States Bureau of Reclamation, might be the master of understatements, remarking, that’s a lot of water.
He said the amount of water lost to evaporation is more than the amount that flows down Clear Creek south of Redding.
Ryan Bailey, the city of Redding’s deputy director of public works for the water department, said the total daily water use during the recent heat wave—including both residential and business users—was around 40 million gallons.
On July 6, the National Weather Service recorded a high of 119 degrees at the Redding Regional Airport, the first time Redding’s temperature had climbed above 118 degrees.
The meteorological service said that from July 5th through the 8th, daily maximum temperatures were consistently higher than the previous record. According to the meteorological service, maximum temperatures over 110 degrees will persist every day until Saturday.
The North State reservoirs are losing water due to the heat, and Lake Shasta isn’t the only one. Trinity Lake, located near Weaverville, lost 828.5 million gallons of water to evaporation in the first nine days of July, while Keswick Lake, near Redding, lost 47.1 million gallons, according to the bureau.
Along its 380-mile journey from its headwaters near Mount Shasta to the Bay Area, the Sacramento River evaporates more water than the bureau tracks.
The bureau’s method for monitoring evaporation involves filling a cylinder with water and then tracking the amount of water lost over a 24-hour period. The volume of water in the lake is estimated by extrapolating the cylinder’s evaporation rate.
