June's arrival, combined with forecasted rain early this week, means it's once again that time of year when snowpack melts and the state's riverflows are set to peak.
Through both natural and man-made activities, the area's waterbodies will ramp back up to seasonal heights this week. The National Oceanic and Atmospheric Administration anticipates the Colorado River and its primary Summit County tributaries will reach their highest 2017 levels this Wednesday, June 7.
The volume-based flow rates, measured as cubic feet per second, on North Tenmile Creek, for example, will rise from about 600 to 900 cfs and the Blue River north of Dillon should grow in the next two days by another couple hundred cfs from its present 600. To offset forthcoming supply, Denver Water, which owns and oversees Dillon Reservoir, stated that it plans to up flows from Dillon Dam into the Lower Blue River from its Monday total of 380 cfs to 600 no later than Tuesday morning, and between 1,400 and 1,800 cfs by the end of the week.
"The snowpack up on the mountain, it's now warmed up and is starting to come off," said Jim Pokrandt, spokesman for the Colorado River District, a public policy agency that closely monitors the region's major waterway. "It's fast water, but shouldn't flood anybody out. All streams will be quicker-paced than people are used to, but the flooding is not the danger."
This considerable increase in each body of water's speed and force, however, does come with strengthened warnings from local law enforcement. The Summit County Sheriff's Office issued a release late last week about the potential hazards that higher water measures pose to those recreating or out walking near riverbanks.
"Over the past week, we've started to see a real uptick in the volume of water that's flowing through our local rivers," Mark Watson, Sheriff's Office special ops sergeant, said in the statement. "Unfortunately, we see people getting in over their heads every year during the spring runoff."
Visitors and residents are urged to use caution when they spot swift currents due to the elevated flows. Individuals lacking proper equipment, experience or training are discouraged from entering the water for recreational activities such as kayaking, fishing or stand-up paddleboarding.
When recreating, appropriately sized life jackets and other personal flotation devices are critical. Anglers should also wear wading belts to prevent water from entering their waders in the case of a fall.
To stay safe around high waters, do not camp or park your car along streams, especially when water levels are fluctuating, or at night when it can be more difficult to notice flood dangers. Allowing young children or dogs to play around storm drains, ditches or a culvert is an unnecessary risk because they are susceptible to slipping on the muddy edges and being swept away. Finally, on the off chance of a flooding this year, get to higher ground immediately and do not attempt to cross a flowing stream, as it only takes 2 feet of water to carry most vehicles away, and just 6 inches of moving water to brush an adult off their feet.
The increased flows, at approximately the same average levels as this time last year, come with their fair share of positives, too.
Escalated releases through next week from reservoirs within the Upper Colorado River Basin benefit a longstanding endangered fish recovery program on a section of the Colorado River upstream from Grand Junction. Four species of fish — the humpback chub, razorback sucker, bonytail and Colorado pikeminnow — are the target of the coordinated effort when the region's waters are at levels that offer an ability to enhance peak flows downstream to remove sediment and other obstructions that hinder spawning habitat for these endangered fish.
North of Silverthorne, additional releases at Green Mountain Reservoir also allow the Bureau of Reclamation to increase power plant capacity and generate more electricity. Those levels could reach approaching 1,400 cfs from the current 418.
Estimating that 40 percent of the winter's snowpack still remains above Dillon, Denver Water is comfortable increasing the flows from Dillon Reservoir into the Lower Blue River that ultimately head to northern Arizona's Lake Powell. That result is threefold, preventing wasteful overflow of the reservoir, maintaining ideal recreational heights on the lake, as well as fulfilling the demands of Lower Basin states based on senior water rights.
"Our experts are monitoring conditions carefully with the goal of ending runoff season with a full reservoir," Matt Wittern, Denver Water Summit County liaison, wrote by email. "That way, we're able to meet our customers' needs while providing locals and tourists alike with valued summer recreation activities that have a positive impact on the local economy."