Your Watershed Column: How to begin to understand ‘dry’
The weekend of May 12 brought a flurry of articles claiming the Colorado River would be reaching its peak stream flow that weekend, nearly a month sooner than normal. With the abundance of early fire restrictions, voluntary water restrictions, and drought in the news, it should come as no surprise that this year is ranking as the fourth driest of over eighty years on record.
The world of water is complex and multi-faceted. There are a lot of different types of measurements within water and snow. Translating statistics into tangible effects can be difficult. So, let’s take a look at the holistic process of stream flow and see what we come up with.
The accumulation of our snowpack serves as a reservoir, and once snowmelt begins that reservoir melts into creeks and rivers providing water to the agricultural industry, riverine environments, and white water runs. Hot temperatures drive the thaw of snow that fills our streams and ditches, and the temperatures we’ve been having in late May have been hot. Snowpack this year was lackluster at best, and at a certain point of the summer there won’t be anymore snow to melt away.
The average date for peak stream flow on the Colorado River at Glenwood Springs is June 7. Runoff really ramps up when temperatures remain above-freezing overnight at higher elevations, resulting in around-the-clock melting of the thick snowpack. Peak flows are reached when low elevation melting is joined by high elevation melting. Afterwards, high elevation melting continues to contribute to flows as long as the snowpack persists.
This year, the Colorado River at the Glenwood gauge did have a small bump on May 12, and then hit its highest peak on May 26 at 6,640 cubic feet per second (cfs). “And you have to look at the numbers too,” said Wendy Ryan of Colorado River Engineering. “We are in a period where river flows are hanging around the 5,000 cfs mark, but that flow is drastically lower than our average for this timeframe.” That average would be a little over 8,000 cfs on May 26, and topping 10,000 cfs for the average peak flow that typically hits on June 7.
So, we’re starting to get to the point of how dry this year really is. But how does this affect our local economies? “The Shoshone Power Plant really saves the Glenwood rafting scene and the environment,” said Ryan. When the plant is operating, it commands a certain flow down the river through Glenwood Canyon, even in the driest of times. It’s enough for boat-able flows, but it’s not enough for the great white water that draws tourists to the region. In the world of agriculture, the Cameo Diversion Dam by Palisade has a similar ability to the Shoshone: to force junior water users in our region to curtail their diversions and send water downstream for its use.
That’s as complex as we’ll get for now, but we didn’t even get into reservoir levels, water rights, augmentation flows, trans-mountain diversions, or the 1922 Colorado River Compact. How might a citizen not tied into the water world feel impacted by all of this? “I think people have their pulse on the river,” said Ryan. But if you happen to feel a little disconnected, check out the fire restrictions implemented for Garfield County. Read the voluntary water restrictions of Aspen that could easily occur in the down valley communities, or read the eight provisions installed in Telluride’s May 4th mandatory water restrictions to get a sampling of what municipal conservation looks like, and go a step further by voluntarily taking one provision up yourself to begin conserving now.
Jon Nicolodi is the Community Outreach Coordinator for the Middle Colorado Watershed Council. To learn more about the MCWC, go to http://www.midcowatershed.org. You can also find them on Facebook at http://facebook.com/midcowatershed.
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