Pueblo Sewage Spill Closes John Martin Reservoir for Labor Day

The water in John Martin Reservoir is already yellow. It’s a murky, cautionary hue that park staff have been warning about for weeks due to massive cyanobacteria blooms. Now, a new threat is coming down the Arkansas River from Pueblo, and it’s not algae. It’s raw sewage.

Will you be able to touch that water this Labor Day weekend? According to Colorado Parks and Wildlife, the answer is no.

On Sunday night, officials issued a directive that will stifle what should be the final surge of summer visitors. Starting Monday, people in the valley need to keep their bodies — and their dogs — out of the reservoir. No swimming, no wading, no tubing, and no paddleboarding. The state park sees roughly 250,000 visitors a year, and this holiday weekend is usually packed with families looking for one last dip before school starts. Instead, they’ll be staring at warning signs posted around the reservoir and the river banks.

The contamination traces back to a failure in Pueblo on Thursday. A section of sewage pipe, which had been repaired long ago and sat inside a stormwater discharge pipe, suffered a pressure burst. More than 4 million gallons of raw sewage intended for a treatment facility discharged through the stormwater pipe into the Arkansas River just east of Interstate 25. The leak was stopped by Aug. 27, but the water hasn’t stopped moving.

The part everyone skips past is how fast that dirty water travels. It’s already hitting the lower valley.

Pueblo County health officials collected samples upstream and downstream of the spill site. The results came back Friday night from the Colorado Department of Public Health and Environment (CDPHE). Upstream, E. coli levels were low. Downstream? They are "extremely high." CDPHE says people should not recreate in or use the river water until testing shows levels have returned to normal. Livestock and pets are also off-limits for drinking from the river in affected areas.

Farmers and ranchers along the Arkansas River got a quick warning from state health and agriculture officials: don’t touch it, don’t use it.

For the reservoir specifically, the situation is layered. The body of water east of Las Animas will remain open for no-contact boating this week, but CDPHE is collecting water-quality samples at the park. The E. coli bacteria and other contaminants flowing southeast from Pueblo have state parks and health officials on high alert.

"Beginning Monday, visitors should avoid swimming, wading, tubing, paddleboarding, fishing and other activities involving direct water contact," the Colorado Parks and Wildlife release stated. "Visitors should also keep pets away from affected water."

Park manager Dan Kirmer acknowledged the awkward reality of their position. "While we cannot fix what is coming downstream, we have an opportunity to prepare and communicate with our visitors before it arrives," Kirmer said.

And that matters because John Martin wasn’t exactly pristine to begin with. Park staff were already sounding warnings about water-quality concerns involving cyanobacteria, or blue-green algae. The reservoir was recently downgraded to a yellow caution status for that reason alone. Now, the toxic algae is joined by sewage-borne bacteria.

Stand there long enough and you can see the river changing color as it approaches the reservoir gates. The water is moving, carrying the signature of a burst pipe in Pueblo all the way to the boating docks. The signs are up. The water is still there, shimmering under the August sun, but it’s not for touching. Not yet.