Disappearing Rio Grande

New? Start here.

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.

Read more

The last reach of the Rio Grande

Cormorants roost on the bare trunks of trees that were drowned by Falcon Reservoir. Photo by: Colin McDonald

I’m back at Falcon Reservoir with a New Year’s resolution to finish this project on schedule and with as many posts about the Rio Grande as I can. 

Things got a bit rough at the end of 2014.  On the last two days on the river, I paddled too many miles to be able to write something coherent.  It got so bad my fiancée sent me a link to this Katy Perry video to encourage me to finish and get home.  It worked in that I got home, but it did little for my ability to put thoughts together.  

But a week with family and friends can do wonders. I am camping at Falcon State Park, ready to launch tomorrow morning and start the last 266 miles of this expedition. It should be a fascinating run.   

Falcon Reservoir is famous for the flooding of the Mexican city of Guerrero, some of the best bass fishing in the United States and for the shooting of David Michael Hartley in 2010. Hartley was killed while driving a jet ski near the Mexican shore.  

It is a place where you can’t paddle slow enough to take it all in or fast enough to feel safe.  

Falcon Dam also marks the start of a reach of the Rio Grande that has become a mecca for birders. It is also an area swarming with state and federal law enforcement officers assigned to stop illegal immigrants.  

For me, it is by far the most confusing reach of the Rio Grande. 

I spent today paddling with Jeff Jones from Laredo. Jones is an advocate for cleaning up the river and a supporter of the Rio Grande International Study Center. His car has a bumper sticker that says “No wall between friends” in reference to the border fence. He loves to get out on the river, where he feels completely safe.   

When we came to shore, we met Jerry Wenger, a retired semi-professional competitive fisherman from Wisconsin. Wenger made his living producing and starring in television shows about hunting and fishing.    

He discovered Falcon Reservoir last winter and spent four months living in a tent to escape the cold up north. This winter he brought a camper to sleep in. Next week he is going to help the park start classes to teach local kids about fishing.    

It was just another sunny and windy day on the lake.  

Then, as I was heating up soup for dinner in the empty campground, an agent with the Texas Department of Public Safety sped through in an unmarked van. He came to a halt at my spot and jumped out. He introduced himself and told me this is a popular place for bringing drugs across the border. He was doing his normal rounds and told me to call if I saw anything. Then he sped off again.  

Overhead I can see a Homeland Security blimp. I can hear helicopters flying in circles. 

It’s a confusing place. I hope I can make some sense of it over these next three weeks.  

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 1:49 p.m. 26.58156 -99.15732


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.


Jessica Lutz
Mike Kane
Project Editor
Barbara Hosler
Copy Editor
News Apps Team Lead | @rdmurphy
Google Journalism Fellow | @jessihamel
Web Designer | @been_hussln
Editor | @ATXjj