2020 Census Colorado Water

In this Monday, July 26, 2021, photograph, Cole Gustafson, a water resource administrator for the Greeley, Colo., Water Department, uses his mobile device to show the location of well heads on the Terry Bison Ranch near of Carr, Colo. Figures released this month show that population growth continues unabated in the South and West, even as temperatures rise and droughts become more common. That in turn has set off a scramble of growing intensity in places like Greeley to find water for the current population, let alone those expected to arrive in coming years.

The problems caused by wildfires aren't only the loss of life and property. They also include happens to municipal water supplies once fires are put out. 

That's not a story that gets told very often, but it's one those attending this summer's Colorado Water Congress in Steamboat Springs heard about on Wednesday.

Adam Jokerst, deputy director for water resources at the city of Greeley, saw first hand last year what keeps water providers up at night once a major fire takes place.

The city has been unable to treat its water supplies for 34 days this summer, Jokerst said, due to the sediment in that water from last year's record-setting Cameron Peak fire, which burned 209,000 acres.

Greeley gets half of its water supplies from the watersheds burned in Cameron Peak: the Big Thompson, Cache la Poudre and the Laramie, which goes into Wyoming. The city also relies on the Colorado River watershed, which was burned during the East Troublesome fire. 

"For a water provider, watersheds are our number one infrastructure," Jokerst said. The watersheds burned in Cameron Peak fire provides water to Fort Collins, Greeley and others. Combined with the East Troublesome fire, that cleared out water supplies for a million people. 

Watersheds are an area of land that contains a common set of streams and rivers that all drain into a single larger body of water. Think of it like the edge of a sink, where all the water eventually goes toward the drain. According to the Environmental Protection Agency, a watershed's purpose is to temporarily store and transport water from the land surface to the water body, like one of Colorado's many rivers and streams.

"The public perception is that disaster ends when the flames go out," Jokerst said. That's the end of risk to lives and property, he said, but for water providers, the real disaster starts when the flames go out.

For Cameron Peak, that means watersheds burned to a crisp. The vegetation burned, but so did the soil. The fires were so hot that sand burns, and even rocks break down into sand. What's left is a moonscape of burned particles that are ready to come off the hillsides, he said.

An unburned watershed has leaves and needles that slow the flow of rain and water. After a fire, however, there's nothing to hold that sediment back.

That sediment repels water and can bring a torrent of ash and sediment-laden water into drinking water supplies.

What that looks like is dark and black, almost like oil, Jokerst said. "We're unable to treat this," since treatment plants aren't set up to deal with sediment.

Another impact  falls on reservoirs. When sediment-laden water flows into a reservoir, it reduces that reservoir's capacity. In addition, that water carries nutrients that can lead to algae blooms, even toxic ones.

The final impact is debris flows, such as the ones at Black Hollow Creek that killed three people and destroyed several homes. The debris flow field was 30 acres, Jokerst said, with rocks the size of cars. But that also means that there are now cars and propane tanks in the primary water supply, which he called a risk to water quality.

So what's a water provider to do?

Jokerst laid out three ways they're mitigating the watershed issue. One is aerial mulching.

This isn't your garden-variety mulch; this is mulch composed of long strands of heavy debris that stick to the hillsides and the watershed. The process involves filling up nets with a ton of mulch and then dropping them on critically burned areas, Jokerst said.

But this kind of mulching is very expensive, at around $2,000 to $3,000 per acre, and there are 11,000 acres that are in critical need of mitigation outside of wilderness areas, Jokerst explained.

"We're only mulching areas where it will work and will hold back the sediment," he said.

Mulch slows down the water. More importantly, combined with the sediment it collects, it turns into soil that supports new growth. 

This provides an opportunity for regrowth, ranging from a few years to a decade.

The other mitigation efforts are "wattles" — that's those long tubes of straw and wood chips you sometimes see along the side of a road, and "log checks," which involves placing logs perpendicular in a gulley to collect sediment.

Managing water in these kinds of situations requires diversity of supply, according to Jokerst. Greely has water from four different basins, but all four burned last year. When they see a wildfire burning in one basin, they can turn to the next.

"This diversity has helped us get by this past year," he said. 

They also work with a variety of partners, particularly in the agriculture sector, which can use some of the dirty water when municipal water systems cannot. It has a lot of good nutrients and acts as a free fertilizer, although it carries the risk of clogging filters and screen in pivot irrigation equipment.

"We couldn’t have done it without close partnerships with the ag community," he said. 

The watersheds affected by Cameron Peak and East Troublesome will need $170 million in mitigation, Jokerst said. The state was able to provide $30 million through 2021 legislation, and through other resources it has increased to $47 million, but that still leaves a gap of $120 million. The primary federal program for helping post-fire mitigation has an annual budget of $300 million, he noted.

"We need almost half of that," which doesn't account for mitigation needed for other fires in the West."

Load comments