A duck swims in Boulder Creek on February 20, 2022. Credit: Harry Fuller

Boulder sits on the northeastern tip of the Colorado Mineral Belt: a swath of ore deposits painting a forward slash across the Rocky Mountains from west of Durango up to Jamestown. Prospectors first discovered gold in the Boulder area in 1859, with silver revealing itself soon thereafter.

Having exhausted what precious metals sat readily available in waterways through placer mining — the practice of separating gold flakes and nuggets from the sand and gravel in creek beds — insatiable miners began hard-rock mining: burrowing into the foothills around Boulder, searching for riches and unearthing poisons.

An estimated 20 tons of rock and soil must be pulled from the earth to create a modern 18 karate gold ring. Mine tailings (the discarded remains of ore, separated from the valuable minerals they once contained) that litter the canyons near Boulder suggest mining of old wasn’t much more efficient. Such tailings are not just a blotch on the landscape; they often contain heavy metals that become dangerous should they make their way into water sources.

Maya MacHamer, director of a nonprofit stewardship organization called Boulder Watershed Collective, is dedicated to ensuring as few of these contaminants make it into our streams as possible. 

“The goal is to pull the tailings, or mine waste, away from where it’s interacting with the water,” MacHamer said. “You can stabilize it on upper slopes away from the stream and cap it with some good soil and get vegetation growing on it. That’s the key to keeping those soils stable. Because hauling it all to the landfill isn’t feasible a lot of the time.”

In 2015, after spending six years as a paramedic in Denver, MacHamer returned to the Boulder area — where she grew up — to focus her attention on local watersheds. Her work began with the Fourmile Watershed Coalition: a group focused on treating wounds caused by the 2013 floods in Fourmile Canyon.

“Fourmile Canyon was severely damaged,” MacHamer said. “They’d had a wildfire in 2010 and flooding in 2011, so by the time the flood came in 2013 that small watershed had a lot of damage.”

Early water testing revealed that MacHamer and her team couldn’t improve the health of the creek without confronting the defacement of the landscape providing its water. Like carbon put into the atmosphere by generations past, mine tailings created by the long dead are a problem that must be solved by the still living.

“We completed a bunch of water quality sampling and were able to see where we had elevated heavy metals in the stream water,” MacHamer said. “If we found elevated levels of lead or arsenic, we would start looking above that area. Sometimes we would have to look at aerial photos or hike around, though some of it was really obvious: the tailings were right there with water flowing next to it.”

Mine tailings can contain the aforementioned arsenic and lead, as well as mercury and cadmium among others. Plant matter, with roots stabilizing soil against runoff, can prevent these metals from making it into nearby streams. But when wildfire burns away the vegetation, as it did in the 2010 Fourmile Canyon Fire (169 homes lost, the most in Colorado history at the time), carcinogens are left unimpeded in their journey towards water.

“The fire burned all the vegetation off [the tailings] and then the flood disrupted piles along the stream,” MacHamer said.

MacHamer and her team addressed these tailings by pulling what they could uphill away from the creek bed, sometimes using rocks as a buffer, and replacing the lost vegetation with native willows: plants with tight, intricate root systems that quickly stabilize soils.

“You can cut a stalk off a willow, soak it in the stream for a week, and then stick it deep in the soil and it will sprout roots and start growing,” MacHamer said. “It’s an awesome, natural solution.”

Even in a culture accustomed to instant gratification, the results from such measures did not disappoint.

“We’ve sampled [creek water] after our projects and we’ve been able to see immediate decreases in arsenic and other metals,” MacHamer said.

People walk along Boulder Creek on their way to the Boulder County Farmers Market on Saturday, June 4. Credit: Jezy J. Gray

‘The stream is a system’

Working in the Fourmile watershed for five years, MacHamer developed skillsets that would soon transfer to greater swaths of Boulder County. One skill was diplomacy in navigating private land ownership while working on stream restoration projects. 

“What we learned from thinking about things holistically was that we had to be thinking about the streams in conjunction with the upper watershed,” MacHamer said. “We can’t really function within property boundaries. We have to think about what the land needs first and then think about those boundaries.”

So when the 2020 Cal-Wood and Lefthand Canyon fires burned in the county, inciting an increased public interest in fire mitigation and forest health, MacHamer and company were ready.

“That’s one of the main things we do: work with private landowners to develop multi-property forest health and fire mitigation projects,” MacHamer said. “It’s the same methodology to how we approach stream restoration. The stream is a system. You need to work across multiple people’s properties to have an effect on that system.”

Co-founding the Boulder Watershed Collective in 2019 (and beginning projects in 2020) with her colleague Cat Price, MacHamer increased the size and scope of her projects while keeping the focus on facilitating collaboration between multiple parties to affect whole systems.

“Our niche is community engagement,” MacHamer said, “There are many people who don’t want to enter into contracts with the county or city — or the government in general. But they’re more willing to do that with a nonprofit or a local community organization.”

A current example of this mediation is a project previously written about by the Boulder Reporting Lab. A forest health/water quality venture in the Barker Reservoir watershed above Nederland, the City of Boulder and the Town of Nederland are looking to thin acres of forest spanning public and private land. The goal of the project is to lower the intensity of future fires, therefore lessening potential ash and sediment runoff into water sources.

“The city isn’t really set up to manage a project like that on private land,” MacHamer said. “So we’re able to manage the funds on private lands and try to compromise for all the values of the different stakeholders invested in the area.”

In a similar experience to Jim Webster of the Wildfire Partners Program, MacHamer says she and her team have found private landowners in the upper watersheds to be engaged and committed to the needs of the land, taking a collective approach in an area that normally attracts those committed to self-reliance.

“[Private landowners] are integrating multiple values into the work they want to do,” MacHamer said. “Of course they want protection for their life safety and the safety of their property. But they also care about ecology and making sure the forest is healthy.”

Moving forward, the Boulder Watershed Collective will continue to evolve, learning and remaining flexible to face the ever-changing challenges that arise in the Boulder area.

“Our goal is to be responsive to community needs and the needs of the land,” MacHamer said. “Where there are water quality impacts, we can focus on that because we have skillsets in that area. And where there are fire mitigation needs on private lands, we can focus on that as well.”

Most of all, however, MacHamer and the Collective will continue to implement the holistic view first learned in Fourmile Canyon: No stream operates independently from the landscape around it.

“It’s really important to take a landscape-level view of our watersheds and the area where we live,” MacHamer said. “Ecosystems function on large scales, so we have to be able to translate our own narrow view of the area we’re looking at and see it in the context of the larger landscape.”

Tim Drugan is the climate and environment reporter for Boulder Reporting Lab, covering wildfires, water and other climate-related issues for Boulder with a focus on explanatory and solutions journalism. He also is the lead writer of BRL Today, our morning newsletter. Tim grew up in New Hampshire and graduated from UNH with a degree in English/Journalism. Email: tim@boulderreportinglab.org.