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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Is this dangerous? Day 180

Colin navigates the canoe around some shallow rocks in a section of the Rio Grande with very little water. Slippery stones and muddy banks that could twist or break an ankle have been a constant concern on the expedition. Photo by: Mike Kane

One of the biggest challenges Mike and I face is analyzing the risk factors along the Rio Grande.  

We are fortunate that we have good gear, plenty of food and enough outdoor experience to stay mostly warm and dry. We have an emergency satellite tracker in case we get injured and need to be evacuated and a good relationship with the U.S. Border Patrol. 

The big variable is the people we will meet. In the last 400 years, there has been a lot of horrific violence near the Rio Grande. The details are gruesome and I don't want to go into the specifics. People have an amazing ability to be cruel.

We have had no indication of that in our entire journey. The closest I have come is a farmer apologizing that he did not have more time to talk about the river because he had to get to town to buy a replacement part for his tractor.

Yes, people cross this river illegally both ways, and they bring illegal goods with them. We see the trails they have cut and the Border Patrol agents looking for them. Most of these people are desperate and have had very difficult journeys. We can't know what their reaction to us would be.  

Anything could happen.

What has happened is we have paddled a lot through mostly pretty scenery and passed a few unpleasant sewer discharge pipes.

The biggest problem we have had is the satellite phone I use to send out posts from remote locations is not working.

I am now between Eagle Pass and Laredo, making miles to be home in time for the holidays. Our families have also been incredibly supportive and understanding, but we don't need to test their patience any more than necessary. I wrote this ahead of time in case I can't get a post out.

I am traveling fast and long every day to reduce exposure to dangerous folks, if there are any. 

I just want to find out what is around the next bend.    

To comment on this post or ask a question, please visit the expedition's Facebook page.

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 7:46 a.m. 28.51174 -100.37469
#2 10:28 a.m. 28.40296 -100.34967
#3 11:49 a.m. 28.34465 -100.31232
#4 1:34 p.m. 28.29688 -100.28952
#5 2:41 p.m. 28.25286 -100.26935
#6 4:01 p.m. 28.20458 -100.2135
#7 5:08 p.m. 28.1679 -100.15366


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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