The Boulder Creek during calm times. This year followed years of low snowpack and runoff that substantially raised the risk level on the creek. Credit: Boulder Reporting Lab

Conditions have to be extreme for the Boulder County Sheriff’s Office to close Boulder Creek to tubing. Now, after a particularly deadly season, the city is considering ways to increase safety, including possibly lowering the closure criteria to safer levels.

During peak runoff this June, when Barker Dam spilled over and spring storms generated flash flooding, two tragic deaths and seven rescues took place in the first three weeks of the month. The flows, however, never got high enough for long enough to trigger a closure, raising questions about whether the current closure threshold is set too high. 

A third drowning death occurred in early July, although the water was fairly calm. The woman reportedly had mobility issues and slipped off a steep slope into the water. 

The current protocol, established by the Sheriff’s Office in consultation with Boulder Fire-Rescue, is to close the creek when the water flows at a sustained rate of 700 cubic feet per second. However, according to Fire Chief Michael Calderazzo, the fire department is concerned about people being on the water above 300 cfs, with or without life jackets.  

“The 300-700 range is deceptively deadly,” he told city council members on July 20.

For each waterway in Boulder County, the threshold for a tubing or recreation closure was established long ago, but how the numbers were chosen is a mystery, according to Boulder County Sheriff Curtis Johnson. Given that fact, Johnson told Boulder Reporting Lab he’s considering changes, and the process is straightforward. 

“Nobody can provide me with any science or data about why that [700] number was chosen,” he said. “I’m certain it predates Chief Calderazzo and fairly certain it goes back at least a decade or more.” 

“I don’t think there are any limitations on us deciding what is safe for our community,” he added. “All [changing the threshold] would involve is a conversation between the Sheriff’s Office and Boulder Fire about what that number should be moving forward.” 

Because climate change is spreading the risk of flooding and altering extreme weather patterns, the county and city might not have a choice, he noted. 

“In a day and age where we’re seeing climate challenges and change, we need to be willing to be nimble and flexible.”

Two of the three deaths this year occurred when the flow rate was around 450 cfs, nowhere near the closure point.  

In the last decade there have been 11 drowning deaths on Boulder Creek, according to data Boulder Reporting Lab obtained through a CORA request. Two of those were from car accidents. Six involved alcohol or other substances, and eight of the nine drownings that weren’t car accidents occurred during peak runoff in May and June. 

The 9-year-old who died in June was the youngest recorded drowning on Boulder Creek in at least 10 years, and the three deaths this summer make it the deadliest year so far. 

After the second death in June, which involved a mother who went into the creek to help a family member before being pulled downstream by the strong current, signage was posted by Parks and Recreation with safety tips and a QR code directing users to the water’s current flow rate. The temporary signs, in Spanish and English, went up along the shoreline.

Allison Rhodes, director of Parks and Recreation, said it’s the city’s goal to install permanent signage by next year in time for peak season. 

“We want to improve education on water safety so that folks are more aware of and prepared for potential hazards,” Rhodes said in an email. 

City council pushes for lowering the threshold

At the city council meeting on July 20 members pushed for more dialogue with the Sheriff’s Office on lowering the threshold. 

“Can we get to a place where we say, that’s a life safety hazard, and we need to do more than put up signs?” Councilmember Matt Benjamin asked. “Can we relook at the parameters on why 700 is the case?”

Johnson told Boulder Reporting Lab his office will determine what is an appropriate closure threshold before next spring, and update it for next runoff season.

Whatever the new threshold is, it will not be set in stone. Johnson said they will remain flexible and update it again if needed.

Calderazzo pointed out that there is a balance to strike, so as to not be too heavy-handed. 

“We definitely want to make sure everyone has an opportunity to weigh in on what’s truly safe and when are we being too restrictive,” he said at the council meeting. 

Like Rhodes, he also stressed the need for better signage. He held up the City of Golden’s flag warning signage, which is similar to wilderness fire warnings with a risk scale using colored flags, as an example of what Boulder is considering. When Smokey the Bear points to red, fire danger is high. When Golden’s signs point to the red flag, recreation is banned on Clear Creek.

According to Dionne Waugh, Boulder Police Department public information officer, water rescues account for a small fraction of service calls. In 2022, they made up .06% of all incidents, although that was a low-incident year overall with no deaths and five rescues. 

This year follows many years of low snowpack and thus low runoff, which created a big swing in risk level.  

Life jackets, other safety suggestions 

Another safety suggestion from city council was to require tubers to wear life jackets, though Rhodes pointed out there is no way to enforce such a law. However in Golden, the city requires businesses that lease tubes to provide life jackets.

Rhodes told council that infrastructure improvements are the first priority. This includes cutting back foliage for better sight lines and making difficult-to-escape areas safer. Another project would involve installing emergency throw-line stations where a bystander can toss in a weighted buoy that is attached to a line on shore. 

Giving bystanders a way to help could save lives. By the time an official rescue is taking place it’s often too late, Calderazzo said. After crews arrive, it can take four or five minutes, or maybe more, before they can get someone out of the water. 

Even just locating the person can be difficult. In the case of a drowning in 2014, a 13-year-old girl was swept six miles downstream.

Educating children is another piece of the plan. Parks and Recreation is partnering with Boulder Valley School District on expanding a program to get more students into swim lessons. She said if a first- or second-grader takes swim lessons for an hour a week for 32 weeks, they’ll be deep water safe. 

“So that is now on our dream list,” Rhodes said. 

She didn’t say whether that skillset transfers to the swiftwater of Boulder Creek, but there are swiftwater safety courses held by outfitters and other organizations like Whitewater Attainment, though these are not free and can cost upwards of $300.

Lessons or not, people will be on the creek next summer, and the city expects to have new safety measures in place to hopefully avoid a repeat of the tragedies seen this year. 

Jenna Sampson is a freelance journalist in Boulder, Colorado. When not dabbling in boat building or rock climbing you can find her nursing an iced coffee in front of a good book. Email:

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