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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A bright spot, day 137

Caelan Devine Ryan works on an escape tunnel for one of his bunkers while Colin McDonald works on his blog post. Photo by: Jessica Lutz

Life is full of difficult decisions, but 11-year-old Caelan Devine Ryan knows not to turn down the opportunity to go on a river trip with his dad on the Rio Grande.

His father, Michael Ryan, is the chief river ranger for Big Bend National Park. He grew up in Marfa, about an hour and half north of the park. He has more than two decades of experience guiding and taking care of visitors on the river.

For Caelan, that means the canoe ride will be so smooth that he can do his homework in the 20-foot canoe while his dad and family friend, Jeff Renfrow, paddle. He can also ask the adults any questions he wants to help him get through the social studies and science packets he has brought along.

When the paddling is done for the day, Caelan puts away his books and gets to work building miniature bunkers in the sandy banks of the river.

The reason a lot of sandy banks are accessible now is because of the work people like Ryan and Renfrow are doing. They are burning and spraying the invasive giant cane that has taken over much of the banks on both sides of the river. Ryan does the work as part of his official capacity to protect visitors and resources. Renfrow works as a contractor to provide the manpower and equipment to get the work done. The work is funded through a host of grants, largely coming from the World Wildlife Foundation and Coca-Cola.

The section we just paddled from Rio Grande Village to the La Linda Bridge has had the most extensive work. Along the edges, you can see the burned tips of cane and slabs of sand that have slid off the bank as the network of roots has weakened and died.

The work is all part of a big experiment to see if removing the cane, which traps sediment, will help the river remove the 10- to 15-foot deep layers of mud and sand on the river banks.

“You just get bombarded with negative images of the border,” Renfrow said. “This is one of bright spots. … It’s not just this never ending story of doom.”

Specifically what Renfrow is talking about is the work being done by the Park Service in cooperation with Mexico to remove the cane and study the impacts. It is one of the few places the two countries are working together on ecological issues on the Rio Grande.

For Ryan, the bright spot is the river itself. After years of being the river ranger, he knows many of the folks who run the river. He has seen their kids grow up and then lead trips of their own.

He has seen monks from San Antonio and students from all parts of Texas take river trips. For the lower canyons, which we are running now, he gave us a boost of confidence. The rapids are not too difficult. Some of them are a bit “boney,” meaning they have a lot of shallow rocks. But those can be easily portaged or boats can be guided through with lines.

“A little common sense will get you through the lower canyons,” Ryan said.

The same is true for dealing with the border. Stopping in Mexico for safety reasons, like scouting rapids or bailing out a swamped boat, is acceptable and not considered willful entry.

And for his son, there is probably no better place for him to be. The sand banks on both sides of the river provide excellent construction material for all kinds of forts, bunkers, castles and anything else Caelan can dream up.

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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 9:10 a.m. 29.36283 -102.84109
#2 11:29 a.m. 29.42571 -102.82953
#3 3:24 p.m. 29.56234 -102.77618


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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