Editor’s note: This is the fifth in a multi-part series submitted by local forest and fire experts addressing the impact of the drought on wildfire, water supply, recreation and Summit County’s forests. The series appears on Friday’s in the Daily.
We’ve had a relatively wet spring and Dillon Reservoir is filling fast. By last account, Denver Water reservoirs were 92 percent filled and water use restrictions were being eased.
Things look good, but looks can be deceiving. While the Front Range may do OK in terms of water this year, we must remember that our Blue River watershed is a headwater source for the Colorado River, which is increasingly over-appropriated. Lake Powell will not fill this year, many downstream users may not receive their share of water and, as has been the case for decades, the Colorado River will dry up in Mexico well short of the Gulf of California.
Watching Lake Dillon fill makes Forest Health Taskforce member Brad Piehl happy but concerned.
“I can’t shake the stark contrast that I am experiencing from working on the High Park Fire restoration,” he said. “I have been designing targeted treatments for watershed protection in the Cache La Poudre watershed, which involves flying over and hiking into some severely burned drainages that supply water to the cities of Fort Collins and Greeley. These blackened landscapes are spewing sediment and debris into the Poudre threatening water quality, fish habitat and recreation, and some people’s lives and homes. We do share one thing in common with the High Park Fire — large areas of beetle-kill that can result in high severity burns in event of wildfire.”
In Summit County we live in a semi-arid climate. Under the best of conditions, there is hardly enough water to meet local demands and the needs of downstream users. Increasing water usage has put a strain on the capacity of the Colorado River basin and the Front Range to meet the needs of users.
Our watersheds in Summit County produce high-quality water. Winter snows melt in the spring, filling not only streams and reservoirs, but underground cavities and near-surface soils which retain and filter water releasing it at a moderate flow throughout the summer and fall. Extended periods of drought reduce the available water. Along with drought, warmer temperatures over the last several decades cause increased loss of the snowpack directly to the air. Reservoirs lose more water through evaporation.
While some of our towns draw on well water to meet public needs, others, such as Dillon, are dependent on surface water. Denver Water and Colorado Springs draw on surface water supplies from Summit County as well. Under changing climate conditions, these source water supplies are threatened.
Large wildfires are an ever-increasing possibility in Colorado, climbing 150 percent since 1970. Such wildfire events can degrade our watersheds for decades; reducing the ability of forest landscapes to filter water, increasing sediment yield and debris flow potential, increasing risk of floods and threatening both short and long-term water supplies and supply infrastructure. Burned areas are still recovering more than 10 years after the Hayman Fire in 2002. Some of these areas may not be forested again in our lifetimes.
It is still uncertain how drought, warmer weather and impacts from the pine beetle have changed wildfire behavior in the High Country. Recent wildfires in high elevation forests increase our concern about forest fires in Summit County. Debris and sediment from post-fire flooding can disrupt reservoirs, intakes and purification systems for decades after the fire. More immediately, power supplies to public water collection and treatment systems can be disrupted if power supply lines are lost.
“As I drive past a nearly full, beautiful Dillon Reservoir I think about Brad,” fellow taskforce member Howard Hallman said. “He’s a very knowledgeable expert and I want him to stay busy, but honestly I hope he doesn’t have any post-fire follow-up work here in Summit County.”
Water experts say the existing strain on the local water supply coupled with the ever-present danger that our streams and watersheds could be compromised by wildfire should weigh on the minds of High Country residents, a constant reminder that water in the arid West is not an unlimited resource.