The Crested Butte News Serving the Gunnison Valley since 1999
Help your trees
The Gunnison Valley has seen above-average precipitation since July, but it hasn’t been enough to correct area water levels. As of Labor Day weekend, water officials cut back releases out of Taylor Reservoir from 200 cubic feet per second (cfs) to 100 cfs, and water levels in local reservoirs are less than half full.
Delaying the inevitable at Taylor Reservoir helped meet summer boating and fishing demands, but recovering from this year’s drought is going to take time. And its impact will stretch beyond ranchers and recreation. Even area trees and forests are feeling the pinch, and landscaping experts are recommending that homeowners take extra care of their trees this fall.
Above-average rainfall came too late
“We’ve had a definite trend of above-average precipitation since July 5, but not significant enough to bring stream flows back to normal levels,” said Frank Kugel, general manager of the Upper Gunnison River Water Conservancy District (the District). “Agricultural production is down significantly as a result of that, but now most of the hay is in the process of being put up or already has been, so the impact has been felt. The rains, if we get more, come too late for this year’s crop.”
Of course, more rain would still be welcome before snow season. Kugel said the valley will be going into the winter and spring storage seasons with well below-normal storage levels. Blue Mesa Reservoir is currently at 46 percent of capacity and 57.5 feet below the spillway, and Taylor Reservoir is at 54 percent of capacity and 28 feet below its spillway.
Kugel added that current projections suggest Blue Mesa will reach 71 feet below the spillway by the end of October. That’s 36 percent of capacity, and not too far from the 2002 low, when the reservoir reached 78 feet below the spillway.
“We’re rapidly approaching that 2002 level, and the park service has closed two of the five boat ramps at Curecanti Recreation Area. Steven’s Creek and Ponderosa are closed,” Kugel said.
The District also had to release water out of Meridian Lake Reservoir in order to meet the Colorado Water Conservation Board’s instream flow rights. That action fulfilled obligations through September 16, but Kugel said more releases are likely.
The outlook is still grim. “It will likely take more than one year to refill Blue Mesa Reservoir, plus the aquifer is well below normal levels so it will take a long time to recharge the ground water table,” Kugel said.
Drought-stressed forests
Water experts aren’t the only ones watching current conditions. Nel Curtiss of Rocky Mountain Trees and Landscaping says the lack of rain has been a topic of conversation among landscaping and tree experts as well.
“We really need to get moisture before we start getting snow and we hope we have higher snow levels this winter. The amount of snow that does stay on the ground has a significant impact on a lot of vegetation, in particular aspen. They took a big hit this year,” Curtiss said.
The impact of drought on trees—particularly aspen—has received a lot of attention since the prolonged drought of the early 2000s. Sudden aspen decline, or SAD, hit nearly a fifth of all aspen and prompted a doctoral student at Stanford University, Colorado native Bill Anderegg, to study just how drought affects the trees.
Traditional thinking assumed that drought caused aspen to shut down the pores in their leaves, and as a result they starved to death in the absence of photosynthesis. But according to Anderegg’s paper, published in December of last year, Colorado aspen were dying of thirst. Much like straws trying to draw the last bit of soda from a cup, the trees’ roots and branches were blocked with air bubbles.
One of the more immediate effects of low snow cover and water is what Curtiss calls leaf scorch, where the leaves turn brown instead of brilliant yellow.
“I just came back from Denver and on Monarch Pass I’m already seeing it,” Curtiss said. “There’s years where we have brilliant fall color and years where the leaves turn brown and fall off. Instead of big patches of gold there are patches of brown.”
The interesting thing about drought, however, is that many effects take a while to be seen. State forester Sam Pankratz says that it took until 2008 to see the full impacts of the 2002 drought, and it wasn’t limited to aspen. “Often times in our forest it takes a little bit to show the impact,” Pankratz said.
In general, a drought stressed tree is less able to respond to other stressors and diseases, and over the last decade or so foresters are seeing more forest health issues like subalpine fir decline and associated root disease and bark beetles. Pankratz has also seen the impact of drought in tree stands on the edge of sage brush habitat.
“There is a really fine line between where trees can be successful and where they can’t,” he explained. Even with normal precipitation levels, these trees are growing in marginal conditions. During a dry year, they just can’t get enough water. “In a year like this sage brush can take back over again and trees move further up the hill.”
Remembering the big picture
The thing to remember, Pankratz says, is that all of these stressors are natural and native to the landscape—it’s seen on a larger scale because the forests are stressed. Assessing the overall health of the forest is better done over the long term, and not just looking at single incidents like the drought periods of 2002 or 2012.
“As forest managers we’re managing a forest that can sometimes live 400 years,” he said. And while anecdotal evidence suggests a drier trend, he said it’s important to remember there are other factors at play like 100 years of fire and disease suppression.
“When you look at the big picture here, we’ve had the most destructive fires and the highest number of structures and acres lost that we’ve seen in the history of our data,” he said.
When fires are allowed to burn in small pockets, like the recent East Coal Creek Fire, it allows a new age class or type of tree to go. But because of suppression a lot of the valley’s trees are the same age, making the forest more susceptible to fire and even bark beetles. Forests are pretty resilient, he said, but the takeaway message is that over the long term, warmer temperatures and drier weather can add up.
Caring for planted trees
While foresters manage the larger forest, there are things homeowners can do to help their trees weather this year’s lack of precipitation. Curtiss is advising her clients to take extra care of their trees during the transition from fall to winter.
“We have a dilemma. We start getting colder temperatures in the next month so we start turning off sprinkler systems. Most people take that as sign they should quit watering, but that’s not the case,” Curtiss said. Rocky Mountain Trees turns off sprinkler systems so the pipes don’t freeze, but trees—especially those that have only been in the ground or at a specific location for three years or less—often need further watering. If it stays warm and dry into November, homeowners could and should water that late into the season.
“We recommend to continue watering plants and trees with a nice deep watering at least once a week—a slow, deep watering so that you’re encouraging those roots to absorb moisture,” Curtiss said. “Once a tree is five years old or more, the roots are extensive enough but at this point, water everything.”
Landowners can also put down mulch to keep moisture in the ground, and if they’re wondering how to tell if their trees have enough moisture there’s one easy way to tell. Curtiss recommends sticking a screwdriver in the ground. If it slides in easily, then the first six inches or so of snow are doing well. If they can’t get it in at all, there isn’t enough moisture.
For her part, Curtiss will be keeping a close eye on what happens with winter weather. She’s hoping that October snow, which she could once count on, returns.
