Preparing for floods

William Miller

It may seem strange for flat-landers or new arrivals to the Sierra foothills, but these hills, bone-dry and sun-baked for much of the year, can become dangerous when winter rains arrive. Just imagine:

  • YLP’s peaceful, bone-dry arroyos and ravines suddenly become watery torrents, picking up and carrying along boulders, limbs, uprooted trees.
  • Days of sheeting rain penetrate into hillsides, washing soil downward across roads, into houses and outbuildings.
  • Swollen streams burst their banks, fan outward and overwhelm bridges, trapping people in their homes. Power goes out as lines come down.
  • So many people are using cell phones that the circuits jam and you can’t call. You can’t drive anywhere. You’re stuck for days and your food supply gets low.

But there’s good news. We still have time to prepare, and lessen its impact on our lives and our homes.

What flooding could do:

After years of drought, it may seem ludicrous to think of YLP awash in streams and ponds. But it’s happened. And as recently as 2007 and 1997. Droughts in California tend to last two, three or four years, according to John Kirk, an engineering geologist with the California Department of Water Resources who lives in YLP. “It’s a land of extremes. And they commonly end in a flood.” When the storms come, he added, “you have hills to the east, storms are heavy and low, so when they cross over the Sierras, they dump loads on the foothills.”

What are the chances?

What about recent predictions by some experts that we may be entering a megadrought that might last for decades? “Yeah, it’s possible,” Kirk said. “But that’s not what recent history shows.” An excellent 2011 book on the subject, “Floods and Droughts in the Tulare Lake Basin,” by John T. Austin, describes in detail all area floods and droughts on record, and shows the back-and-forth nature of these events — floods followed by droughts followed by floods, etc.

Ken Harrington, manager of the Yosemite Spring Park Utility Co., YLP’s “water company,” and a longtime YLP resident, recalls the “Miracle March” of 1993 after six years of drought: “It rained pretty much the entire month.” January 1997 was much worse, he said, when the Clubhouse lake filled up, driveways were washed out and the Yosemite Springs Parkway bridge near Highway 41 was under water.

How to prepare:

YLP residents are urged to gather: water, plus an NOAA weather radio to stay in touch, fresh batteries, canned food, and get gutters and culverts cleaned. “Check slopes and if I am downhill from something, take steps to reinforce my slopes," Kirk said. "(Also) put together a communication plan, with an out-of-state contact, so they can have a common person to talk to, and (tell them) if separated where we’ll be.”

The state encourages “neighborhood preparedness” including meetings to develop plans to deal with localized flooding, wind damage and power outages, as well as arrangements to evacuate.