EMBUDO – There’s no evidence that John Wesley Powell, the second director of the U.S. Geological Survey, ever made it to this stretch of the Rio Grande back in the winter of 1888-89, when he dispatched a crew to the site to establish the nation’s first river flow measurement site.
Powell’s most recent successor, acting USGS Director Suzette Kimball corrected that oversight last week, topping off a 125th anniversary celebration at the site by donning waders to take a stream flow measurement herself and, in the finest USGS tradition, falling into the Rio Grande.
The festivities happened to fall on Earth Day, but Kimball downplayed the significance. “Most of our scientists will tell you that any day and every day is Earth Day for them,” she said during a commemoration ceremony.
In the world of U.S. water management, this narrow strip where the river funnels between high bluffs is historic.
Powell, most famous as the first person to survey the Grand Canyon, had realized that the ambitions of the continent’s European immigrants spreading west across North America were running up against an arid reality that Easterners failed to understand. Collective effort would be needed to confront the region’s aridity,
Powell realized, and one of the first things the young nation needed was to measure how much water there was in the rivers.
Powell’s young agency, founded a decade before, dispatched a crew to Embudo in the winter of 1888-89 to try to figure out how to do that. The initial team that winter was led by Frederick Newell, who 13 years later became the founding director of the U.S. Reclamation Service, the predecessor to today’s U.S. Bureau of Reclamation, and the agency responsible for the dams and irrigation systems that changed the western U.S. forever.
The first experiment, done on the Rio Grande at Embudo, just north of Española, was simple. They surveyed the channel’s depth and width, then built a simple pontoon boat and floated downstream. A bit of simple arithmetic – the river’s cross section multiplied by the speed of the flowing water – gave their first measurement of the volume of water flowing past Embudo.
To add precision, they borrowed a meter used by the Navy to measure tidal flow, modifying it at a Denver machine shop for use in rivers. The device, which looks like a wind vane with a propeller on one end, measured the water’s velocity more precisely than the pontoon boat. It looks little different from measurement devices you still see in use today.
Careful channel surveys and velocity measurements are used to develop “stage-discharge tables” that show how much water is flowing past a point for a given height of water. Then, as long as the channel doesn’t change, all you need is a measurement of the river’s elevation, which is a much simpler task, to determine how much water is flowing by.
It’s awe-inspiring,” said Mark Gunn, USGS Albuquerque data chief and the office’s unofficial history buff. “Those guys were really smart.”
Once the techniques were developed, the station master at the Embudo stop on the Denver and Rio Grande Western Railroad would go out and record the river’s height twice a day, mailing in the results monthly. But because all river channels change over time, eventually a human has to go out in the field, don waders, survey the cross section and measure the flow. Sometimes a remote-controlled boat is now used, but the basic technique is the same.
Today, you don’t need to wait for mail service to check the numbers. An automated gauge records the river’s height at 15-minute intervals and beams the data to a communications satellite. You can sit at your computer and see how much water is flowing past the Embudo gauge in very close to real time, or even look it up on your mobile phone if you’ve got data access.
The gauges are critical for managing the state’s water, a string of state and federal dignitaries said one after another during last week’s ceremony. Because of their importance, the state of New Mexico and the Bureau of Reclamation are among a number of water agencies that help fund the stream gauge system’s operation. While budget cuts have threatened gauges in other parts of the country, officials say New Mexico’s network has survived the federal fiscal storm.
I confess to a water nerd’s enthusiasm for the data. Using the USGS Web app, I’ll stand next to a gauge along the Rio Grande, pull out my phone and look up the flow in real time. Though, sadly, when I tried last week while we were gathered at Embudo, I couldn’t. I couldn’t get cell service in the canyon.