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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Water for Texas, Day 73

Colin McDonald paddles across Caballo Lake; this is the last time he will be able to use the canoe in New Mexico. Photo by: Erich Schlegel

We are still in New Mexico but paddling on Texas' “project water.”

This is how water policy works out here. It makes sense if you understand the history and accept it on its own terms.

“The Project,” aka the dams of Elephant Butte and Caballo, was supposed to settle the water issues between Mexico, Texas and New Mexico back in 1916.

They did not. The current fight is on track to land before the U.S. Supreme Court. It is centered on two questions: Are the wells along the Rio Grande in New Mexico pulling so much water out of the river that Texas is not getting its share? And is the delivery point to Texas at Elephant Butte or the Texas state line?

This is as hilarious as water policy gets to me. But I’ve also spent most of the day paddling and walking across mud under a blazing sun. Everything is funny to me right now.

In Texas, groundwater is treated legally like it is not connected to surface water. You can pump as much as you can use from below your land with no regard for what that does to your neighbor’s wells or local steams. This is thanks to a ruling by the Texas Supreme Court in 1904. There are some exceptions if you are in a groundwater district, but their legal authority to actually limit pumping is still in question.

Texas is arguing that in New Mexico, the groundwater below the Rio Grande is connected to the water in the river, and the pumpers should be mindful of the impact their pumping has on their neighbors, aka Texas. But let’s not talk about the wells in Texas that draw from the same aquifer and also impact the flow of the Rio Grande.   

The other crazy argument is the one New Mexico is using. The state argues the delivery point for Texas’ water is not at the state line but at Elephant Butte Dam. There is nothing in the compact that says water actually has to be delivered to Texas, just that it has to be sent through the dam. So Texas can have its water, it just does not have a right receive it.  

Regardless of the political boundaries and legal theories, the river is mostly dry for the next 400 miles. The irrigation season is over.  We're putting away the canoes and breaking out the walking shoes. 

Laughing makes the walking easier.

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 5:57 p.m. 32.97419 -107.29099
#2 6:40 p.m. 32.95797 -107.30042
#3 9:25 p.m. 32.91091 -107.30679


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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