Disappearing Rio Grande

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Why Follow the Rio Grande

by Colin McDonald | Feb. 11, 2015

The Rio Grande is disappearing. Demand for water is growing as snow packs shrink, rain patterns shift and average temperatures rise faster than they ever have in the past 11,000 years.

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Horses, Snakes and Sheep, Day 19

A herd of horses runs across public land along the Rio Grande near the Colorado and New Mexico state line. Photo by: Colin McDonald

For the first time in local memory, bighorn sheep are being spotted in the southern end of the San Luis Valley.

The sheep are believed to be part of a growing herd that was reintroduced to the cliffs of the Rio Grande Gorge in New Mexico almost a decade ago.

For Brian Bechaver, the Colorado game warden who is assigned to this 1,000-square-mile area, it’s a big deal.  The only records of the sheep in the area are pictures of them sketched into the rocks along the river.

But the sheep are not going to find much of a welcome if they continue to move north where the population of horses has exploded.

When Bechaver, 44, was growing and roaming these hills, seeing a horse was a rare sight.

Now, he estimates there are more than 500.  Every small canyon and arroyo seems to have its own herd of about 25 horses.

These are not wild horses. These are animals that have been dumped by people unwilling to take care of them. They have then bred like rabbits.  Bechaver said that in four years, a horse herd could double in size.

Unlike the nibbling done by elk and deer, which the horses have now mostly pushed out of the valley, horses can eat plants down to the root.

Bechaver said it’s not just that the horses are overgrazing, they are turning some of the hills into sand dunes.

Although from a biological standpoint, the horses are worse than feral pigs, which anyone can shoot, the politics and romantic notions about horses protect them.

“People think they are doing them a favor,” Bechaver said of the people who release the horses.  “But they are not.”

Bechaver has seen horses limping on injured legs and others being choked by their halters. He shoots them when it is the most humane thing to do.

But the population grows and the horses expand their territory.  The only living willows along the riverbanks now are the ones that are protected by strong fences.

Unfortunately, no one wants the horses and too many don’t want to see them killed.

“You can’t give them away,” Bechaver said.

He says bighorn sheep may fare better than the elk and the deer and be able to live on steep cliffs where the horses can’t.  But the horses rule the grasslands along the river and the plains.

And then there are the rattlesnakes.  They seem to be doing quite well and provide an excellent reminder to be careful where you step.  There are much worse things to step on than a pile of horse dung.

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Air temperature (°C)
Conductivity (µS/cm)
Depth of Measurement (meters)
Dissolved oxygen (mg/L)
E. coli colonies per 100 ml
pH level
Secchi disk transparency (meters)
Water temperature (°C)

What do these numbers mean?

As they travel, Colin and Erich are taking water samples for the following periodic water quality tests. In partnership with The Meadows Center for Water and the Environment’s Texas Stream Team Program at Texas State University, the results will be added to a public database it helps maintain for research and monitoring water quality.

Air/Water Temperature
Temperature impacts everything from the amount of oxygen in the water and the metabolism of aquatic species to how easily compounds dissolve. Most species can tolerate slow seasonal changes but can go into thermal stress or shock when temperatures change by more than one or two degrees Celsius in 24 hours.
pH Level
The pH scale measures water’s acidity and runs on a logarithmic scale from 1.0 to 14.0, with 7.0 considered neutral. Anything below 7 is acidic and anything above is basic. A pH range of 6.5 to 8.2 is optimal for most organisms.
Dissolved Oxygen
Oxygen is just as vital for life below the surface as it is above. The amount needed varies according to species and stage of life, but generally 5.0 to 6.0 milligrams per liter is required for growth and activity. Levels bellow 3.0 mg/L are stressful to most fish species and levels below 2.0 mg/L for an extended period of time will cause fish kills.
Conductivity levels depend mainly on how easily the rocks and soils a stream passes through dissolve. For example, high levels of conductivity are often found with water that passes through limestone and gypsum because it will pick up the calcium, carbonate and sulfate from those rock formations. However, discharges into a water body, such as a failing sewage system, can also raise the conductivity because of the presence of chloride, phosphate and nitrate.
Water Clarity
Turbid water can come from high levels of sediment or plankton. Both will block sunlight to aquatic plants and the sediments can carry pollution such as nutrients and pesticides. Low levels of turbidity may indicate a healthy and well-functioning ecosystem. High levels can be an indicator of runoff from eroding soils or blooms of microscopic plankton due to high levels of nutrients.
E. coli
E. coli bacteria are found in the colon of warm-blooded animals. If the pathogen is found in water it’s an indicator that fecal mater from humans, pets, livestock or wildlife is also present and may pose a public health threat. For drinking water the standard is to have no E. coli. But almost all non-treated water has some E. coli in it and at low levels it does not represent a substantial health threat to those who swim or wade in it. The Environmental Protection Agency has set the water quality standard for these types of activities at 126 colony forming units per 100 mL.
Secchi disk transparency
The Secchi disk is a plain white, circular disk used to measure water transparency in bodies of water. It is lowered into the water of a lake or other water body until it can be no longer seen. This depth of disappearance, called the Secchi disk transparency, is a conventional measure of the transparency of the water.

While making his way to the Gulf of Mexico, Colin will be periodically activating a device that uses satellite technology to share his current location. Use this map to see where he traveled on this day.

Check-In Time of Check-In (CST) Latitude Longitude
#1 9:57 a.m. 37.30342 -105.74181
#2 10:20 a.m. 37.30211 -105.73285
#3 11:10 a.m. 37.2731 -105.72629
#4 11:44 a.m. 37.2543 -105.74115
#5 12:29 p.m. 37.22105 -105.74368
#6 1:31 p.m. 37.18855 -105.7338
#7 2:34 p.m. 37.18084 -105.73013
#8 8:53 p.m. 37.17364 -105.73402


To report on and understand the haphazard irrigation system the Rio Grande has become and the changes it is going through, Colin decided the best approach would be to travel the length of the Rio Grande by foot and small boat.

He knew it would give him a unique perspective on a river that few understand. It did require many long days of moving slowly and camping on muddy riverbanks, but Colin likes that sort of thing.

The benefit was it provided access to people who wanted to share their stories and experiences with the Rio Grande. Via Facebook and chance encounters, Colin made instant friends who opened their homes. They provided help from loaning their trucks to their cell phone contact lists to help tell the story of the Rio Grande.

The trip would not have been possible without their help, along with the dedicated assistance of David Lozano, Jason Jones and Daniel Dibona, who drove thousands of miles to get people and boats in place.


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