Del Valle floods; rarity at Pillar Point

Tom Stienstra is The San Francisco Chronicle’s outdoors writer. Email: tstienstra@ sfchronicle.com Twitter: @StienstraTom

From Del Valle Reservoir to the Sierra Crest, from the Russian River to Shasta Lake, conditions in the outdoors for this three-day weekend span from Nirvana to nightmare. Del Valle floods: In the East Bay hills, high inflows from Arroyo Valle raised Del Valle Reservoir over its banks Friday and threatened the campground and recreation facilities. The park will be closed through March 3, said Jen Vanya at East Bay Parks. Mammoth Mountain: At the 11,053-foot summit, season snowpack was measured at 543 inches, with a 225-inch base snowpack, reported Tim LeRoy from Mammoth. Visualize that. Rare sighting: At Pillar Point Harbor, kayaker Bart Selby saw a northern gannet, a bird from the north Atlantic Ocean. His sighting was verified by bird experts. “I assume that means it had to come through the high Arctic,” Selby said. No. 1 in California: A rain gauge at Venado in the Russian River watershed, located north of the Armstrong Redwoods, hit 69.72 inches for the season, the highest in California. Water watch: At Lake Berryessa, the gauge hit 93 percent full and the water level needs to come up 10 feet to spill into a bell-mouth called the Glory Hole. Giant Shasta: The state’s No. 1 recreation lake, Shasta Lake, hit 73 percent full, high enough to open all of the boat ramps, and up from about 45 percent since December. It hits peak in midMay. Good and bad timing: Conditions appear nearly perfect for Monday and Tuesday to be among the best ski days of the year at Tahoe, with cold, clearing weather and surface conditions refreshed by sugary powder, runs groomed into soft corduroy. Problem is, the timing was a disaster for many travelers, and they will miss it; Interstate 80 and U.S. 50 were closed off and on because of blizzards and avalanche warnings Thursday night, and parts of Friday and Saturday. Bad surprise: Those renting vacation homes at Tahoe during big snowstorms can arrive and find the driveways of their rentals buried in high snow, reported field scout Geoff Chin.