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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On our own, Day 144

The broken layers of limestone that make the safest and cleanest campsites along the high-flowing Rio Grande are about to greet the sunrise. Photo by: Colin McDonald

We have not seen anyone for two days.  We have seen some houses on bluffs several hundred feet above the river on the Texas side and a few dirt roads on both banks, but not a single person.   

Because we are now below the usual takeout for the Lower Canyons and paddling mid-week, we will likely not see anyone until we reach Langtry, Texas, some 60 miles downstream.  

What we are seeing is a lot more biodiversity. Mussel shells are becoming common and larger along the muddy riverbanks. There are more turtles basking in the sun. The great blue herons seem to like this stretch as well and we see several every day. A pair of red-tailed hawks circled our camp this evening. I literally stumbled over a foot-long catfish that was flopping in the shallows alongside a rapid this afternoon.

No other section of the Rio Grande over the last 1,100 miles has felt this wild and remote.  

Adding to the adventure, our only guide to the region is a Geological Survey map from 1985. It’s a great map that was given to us by Michael Ryan, National Park Service river ranger. But it forces us to rely on our ears and pay attention to changes in the canyon walls to guess when rapids are coming or where there could be a campsite.  

We have already run three rapids this way.  

The last one had a nice, low overhanging cliff at the end on the Texas bank. It was at an angle to the main flow, so the majority of the river was forced against the wall. Some of the water boiled up against the limestone, but most seemed to just slip downward.   

I got a great view of this from the stern of the canoe as we were sucked in under the overhang. I had just enough time to wonder if the canoe would be crushed by the weight of the river pushing it against the rock or if it would just get sucked below the surface. It was like being in the backseat of a car that is stuck on the railroad tracks as a train rolls in. 

But, with perfect timing, Jessica was able to get off two powerful strokes while bent in half under the overhang. She propelled the bow of the canoe past the end of the wall. With the bow in the clear water that was moving away from the wall, the stern broke away from the grip of the current, saving us from a very unpleasant swim.  

Although she had little experience with camping or paddling, Jessica jumped at the chance to see the Lower Canyons and shoot photos for this blog. After nearly getting hypothermia and seeing some of the canyon walls from a very close distance, she still says she is happy to have come and is ready for the next 90 miles of river we have to travel.   

Her nickname is Big Strokes. 

But after some 20 miles of paddling and the close encounter with the canyon wall, we both felt we had covered enough ground. We started looking for the broken layers of limestone that create the rock ledges that we like to camp on.  

We found some that were freshly washed by the recent flood. Based off the high water mark, the rocks we are sleeping on tonight were under 6 feet of water a couple days ago.  

Maybe that is why no one is around.

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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 10:01 a.m. 29.84851 -102.23245
#2 12:58 p.m. 29.80829 -102.14749
#3 2:22 p.m. 29.78639 -102.06793
#4 3:35 p.m. 29.80263 -102.02148


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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