Staff Reports · 2 min read
GARDNERVILLE, Nev. — As Carson Valley and much of Western Nevada braces for almost certain flooding this weekend, the biggest question heading into the National Weather Service’s flood warning for the Carson River starting Sunday is “How bad is it going to be?”
With many variables in play, most notably how much rain actually falls, it’s a nearly impossible question to answer fully — though signs point more toward the magnitude of 2005 than 1997.
Snowpack above the Carson River played a major role in both the floods of 2005 and 1997.
Moisture trapped in snow escapes with incoming rain and joins along for the ride down the river, significantly adding to flows.
As of Saturday morning, snowpack above the Carson River was measured at 120 percent of normal for the date, according United States Department of Agriculture Natural Resources Conservation Service.
Snow Telemetry sensors on Dec. 31 2005 registered 166 percent of normal.
On Dec. 31, 1996 leading into the 1997 flood, the available moisture in the snowpack was 240 percent of normal.
The available moisture in the snow just prior to the 2005 and 1997 floods was measured higher than Saturday morning at all points except for the lowest measured elevations in the Carson River region.
2017 holds the upper hand at Spratt Creek (6,060 feet) over both prior floods, showing 2.2 snow/water inches — or 88 percent of normal — compared to none in 2005 and 1.5 snow/water inches (79 percent) in 1997.
The sensor at Poison Flat (7,736 feet) shows 8.5 water inches, higher than the 7.8 in 2005 but lower than the 14.7 in 1996/97.
The snowpack tends to be thinner at lower elevations, making it easier for water to soak through and/or melt, creating more runoff.
Otherwise the 2017 measurements draw near to, but don’t surpass the 2005 measurements at Forestdale Creek (8,017 feet), Blue Lakes (8,057 feet), Burnside Lake (8,129 feet), Monitor Pass (8,310 feet), Carson Pass (8,360 feet), Horse Meadow (8,557 feet) and Ebbetts Pass (8,660 feet).
Fewer sensors were available in 1996/97, but the numbers were significantly higher at Ebbetts Pass, Monitor Pass and Blue Lakes than Saturday morning.
For updated information on the flood watch, visit this link.