With the winter of 2013-14 winding its way toward the first day of spring on March 20, Colorado’s climatologists and water managers are keeping a careful eye on the monitors and gauges that speak to the conditions that the new season might bring.
To that end, much of what was presented during this week’s drought webinar by the Colorado Climate Center was positive. Snowpack in Colorado’s northern and central Rockies is near to well above normal. There’s so much snow in the South Platte River Basin that water managers there are “holding their breath” for a normal, well-behaved runoff when melting begins in earnest, said assistant State Climatologist Wendy Ryan.
In other words, they don’t want an unexpected streak of 90 degree days that could create a deluge in river channels damaged from last September’s massive flooding.
Elsewhere in the state, conditions range from the mostly positive to the downright worrisome. Snowpack in the San Juan Mountains is 90 percent of average, with drier conditions in the Four Corners. In the Rio Grande and lower Arkansas River basins, however, where drought has persisted in a multi-state region for three years going on four, conditions are less promising.
Snowpack in the Rio Grande is only 74 percent of normal, which could have grim portent for New Mexico and D2 (severe), D3 (extreme) and D4 (exceptional) drought conditions now exist in Colorado’s southeastern corner. Springs storms and a healthy monsoon season could change all of that, of course, but for now – given recent history – there are plenty of reasons to worry.
The southeastern plains received moisture from September’s epic storms, but by that time ranchers had sold off most of their cattle because there was no water and no wheat. What grew from the moisture instead is what Ryan described as an “epidemic of tumbleweed.”
In Crowley County, road graders are being used to clear highways of the wind-driven Russian thistles, and residents have had their homes and barns nearly buried. Massed tumbleweed also pose a significant fire danger, Ryan. The region has also suffered winter dust storms, never a good sign. And once again this year, the outcome for winter wheat is a big question mark.
Getting back to the South Platte, some irrigation districts there may suffer an "artificial" drought this year, Ryan said, because irrigation structures damaged by the September floods have not been fixed and will not be fixed by runoff. In some cases, river channels have changed course to the extent that water no longer laps against the headgates for irrigation ditches.
Among other measures followed by the climate center at Colorado State University, is reservoir water storage. There, too, the news ranged from good to not so good. Lake Dillon is standing at 111 per cent of average and 94 percent full, while Lake Granby is 91 percent of average and 47 percent full – good numbers for this time of year. But the massive Lake Powell is only 56 percent of average, 39 percent full.