Winter 2019 is finally winding down and even though the official water year isn’t over until Sept. 30, it’s a good time to review. I realize that local and even national media relentlessly touted “record snowfall” headlines for the Tahoe Sierra this past winter, but as is often the case these days, the claims were generally overblown. No doubt that ski resort snowfall tallies for February set new records, but it wasn’t enough to bump seasonal snowfall amounts even close to historic levels measured at the Central Sierra Snow Laboratory (CSSL) near Donner Pass.
Precipitation, however, is a more critical metric than snow and the news in that category is good. Characterized by intense snowstorms and prolonged periods of generally wet and often gloomy weather, the winter of 2019 resulted in an impressive amount of precipitation (rain plus snow water equivalent). The June 1 data dispatch from Randall Osterhuber, lead scientist at the CSSL, reported 84.4 inches of precipitation measured so far at Donner Pass. That ranks 2019 at No. 10 in precipitation since 1871, with the potential to surpass 2011 at No. 9 with just 0.6 inches more. Even so, 2019’s current precipitation total at the snow lab is 37 inches shy of 2017’s — the wettest winter of record. If you’re a local who has lived in the Tahoe area since 1982, you have now enjoyed or endured eight of the Top 10 wettest years in history.
Tahoe Sierra snowfall tallies for 2019 were robust, but other than February’s blitzkrieg not record setting. Winter started off normal with precipitation totals running right about average on Feb. 1. But then everything changed. At the end of January, an anemic El Niño event simmering in the Pacific Ocean finally gained traction with the atmosphere. At the beginning of February, a strong winter storm punched into the region and opened the storm door for an uninterrupted series of very cold and potent low-pressure systems. The barrage lasted all month and snowfall totals reflect that. The snow lab was buried with 221 inches in February — more than 18 feet — exponentially above the month’s average of 73 inches. Stellar, yes, but keep in mind that 273 inches fell in January 2017, which set new January and any month snowfall records at the lab.
The real winners in the 2019 snowfall bonanza were Tahoe Sierra resorts and their customers. Totals ranged from 267 inches (22 feet) at Sugar Bowl to Homewood Mountain Resort with a mind-boggling 328 inches (27 feet) in just 28 days — about 1 foot a day. (When it comes to monthly snowfall totals, February has a two- or three-day disadvantage compared to other months.) The dry, virtually bottomless powder snow in February made for an unprecedented run of epic skiing and riding days. We got clobbered, but February 2019 still failed to overtake the current California monthly snowfall record of 390 inches (32.5 feet) measured at Tamarack south of Lake Tahoe during January 1911. As of this writing, the snow lab is holding at 488 inches of snow so far this year, which ranks the 2018-19 winter at No. 31 since snowfall records began there in 1879.
Lake Tahoe and Truckee River watersheds were saturated with significant precipitation this winter, but hydrologists and water-management officials have done a nice job regulating runoff, even with a wet spring added to the mix. Thanks to aggressive early releases, the current flow out of the Truckee River Dam is 605 cfs as of press time — about 4,500 gallons of water per second — substantial but a manageable discharge for avoiding negative downstream impacts. Lake Tahoe is close to its legal maximum surface elevation and storage capacity, but experts anticipate having enough room left in Big Blue to handle forthcoming runoff from the substantial upper elevation snowpack. It doesn’t always work out that way — as when 40 years ago in 1969 when a heavy-hitting winter generated destructive water issues.
Destructive winter of 1969
Winter 1969 started slow, but by the end of January regional ski areas were reporting remarkable snow depths for so early in the season. Squaw Valley operations coped with a 23-foot base while Boreal Mountain Resort on Donner Pass reported drifts 18 to 40 feet deep. The active storm pattern set several Nevada snowfall records that still stand. On Valentine’s Day, the Silver State’s 24-hour snowfall record was broken when 3 feet buried Daggett Pass near the Kingsbury Grade, east of Lake Tahoe. A total of 139 inches of snow fell on Daggett Pass during February 1969 and the maximum snow depth there reached 14.5 feet — both new state records. Avalanches and drifts closed the Mount Rose Highway for 37 days.
The storms of 1968-69 set weather benchmarks in the Silver State and dumped 601 inches (50 feet) of snow at the Central Sierra Snow Lab but managing the Lake Tahoe reservoir proved to be the biggest hurtle. Wet winters during the 1960s, combined with a federal water-management policy that emphasized capacity storage in Lake Tahoe, meant that water levels remained high those years. When nearly 40 inches of precipitation fell in 90 days in 1969 — out of a seasonal total of more than 65 inches — there was no room to store the tremendous volume of runoff.
Federal Water Master Claude Dukes did his best to alleviate the danger of Tahoe exceeding its legally mandated maximum water level of 6,229.1 feet. He opened most of the 17 gates in the Tahoe dam, which produced a colossal outflow of water. The Tahoe release joined other engorged creeks and tributary rivers draining the overwhelmed Truckee River watershed, which flooded Reno, Nev. Even as June approached, Dukes was still trying to balance the potential for damage downstream versus breaching the Tahoe mandate, a limit that had been set by a federal court order in 1915.
When unusually warm temperatures accelerated snow melt in early June, Dukes again increased releases, but Lake Tahoe kept rising. On June 16, a thunderstorm dumped nearly 1 inch of rain in a few hours, pushing Big Blue over the legal limit to 6,229.03. Dukes was out of options. For the first time since the dam’s construction, he fully opened all the gates on June 20, sending 2,620 cfs downstream. The powerful surge took out three bridges on the Truckee River. History repeated itself in January 1997 when high water forced Federal Water Master Garry Stone to open all gates at the Tahoe dam, releasing a record flow of 2,690 cfs. Once again, Reno went underwater.