Snowpack and Our Watershed

Cian McGillicuddyFly FishingLeave a Comment

After triple-digit accumulations of snow the last week of 2021, Aspen is a winter wonderland! Though we are just as excited as you are to be skiing fresh powder, we’re even more excited about what this snow means for our rivers. Having a healthy snowpack is incredibly important because snowmelt provides the cold, clean water that insects and fish need to survive during the spring and summer months. Last year, much of the west experienced below average snowpack, drought, and high water temperatures during the summer months. As anglers, boaters and residents of the Rocky Mountain West, snowpack plays a prominent role in our lives.

“Snowpack” describes the layers of snow that accumulate over the winter in cold, high elevation areas. Monitoring snowpack helps us understand how much water we can expect to be moving through our valley during the following year. Studying the snow-water equivalent (SWE) stored in the mountains helps us predict summer fishing conditions, but it also helps scientists track changes in climate, helps farmers plan their water usage, and helps towns prepare for floods and drought. 

Ice and snow on the Roaring Fork River on 12/20/21.

The headwaters of the Roaring Fork River start southeast of Aspen, in the Hunter-Fryingpan wilderness near the top of  Independence Pass. As the Roaring Fork flows down the valley, it is joined by Hunter Creek, then Castle Creek and Maroon Creek, Brush Creek and Snowmass Creek, the Frying Pan River in Basalt, and the Crystal River below Carbondale, and finally it flows into the Colorado River at Glenwood Springs. Though each of these tributaries have distinct characteristics, they are all connected. The Roaring Fork River relies on snowmelt from each of them, just as the Colorado River Basin relies on the Roaring Fork as a tributary.

Here is the most recent snowpack report from the Roaring Fork Conservancy!

Snowpack in the Roaring Fork Valley is at 153% of normal for this time of year! This is great news, and we hope the snow stays!

But how do these winter numbers translate to the spring and summer? As temperatures warm in the spring, snow begins to melt and “run off” into drainages and tributaries that feed the Roaring Fork. This “runoff” period usually peaks in the late spring or early summer. During runoff, the flows in the Roaring Fork river can rise to over ten times their base flow! This surge in flow clears the river of sediment, making the substrate of our rivers more suitable for insects and trout, allowing future generations of wildlife to thrive. Healthy, consistent spring runoff is an essential part of our ecosystem. 

After runoff, snowmelt slows gradually and causes flows to drop and water temperatures to rise. This slow and steady change catalyzes the delicate and complex cycle of insect hatches that make trout fishing in the summer such a blast! The incredible Caddis, PMD, Green Drake, Yellow Sally and BWO hatches that we get in the summer are intimately tied to river flow, water temperature and ultimately snowpack. Healthy bug life makes for happy trout, but both trout and their invertebrate prey need cold, oxygen rich water in order to survive. 

During a year with a healthy snowpack, snowmelt can feed our rivers through most of the summer. But that alone doesn’t get us to the finish line. Our rivers also rely on precipitation to supplement the impact of snowmelt. During hot summers with little precipitation, our snowpack tends to melt more quickly, and we don’t have the supplemental precipitation to keep our rivers cool– presenting a dual threat to the ecosystem. 

Let’s take a look at some numbers from last season.

Though our snowpack last year was just slightly below average, drought in the late spring and early summer depleted our water reserves early, leaving our rivers and streams at less than half of normal by the end of July. This demonstrates that snowpack alone can’t keep our rivers healthy through the summer. However, it definitely helps. Pray for snow in the winter, and rain in the summer!

Though last summer showed us the delicacy of our ecosystem, we’re very optimistic for the coming year, not only for our community but for the entire West. The Roaring Fork is our favorite river in the world, but it’s only one part of the picture. Our watershed flows into the Colorado River which supports our neighboring fly shops down river, irrigates farm land, and supplies much of the southwest with water. Healthy snowpack is important for us, our precious ecosystem and those down river. 

Keep a spoon under your pillow, enjoy the snow covered banks and get excited for another year of epic fishing!

Written by Cian McGillicuddy, Photos by Anna Stonehouse

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