Category: August 2017

The Rio Puerco watershed (RPW) in northwestern New Mexico is a highly dynamic and diverse ecological system that has a long history of mostly deleterious anthropogenic alterations. By the early 1900s, heavy grazing pressure and the diversion of water resources for crop irrigation and livestock watering had resulted in drastic alterations to ecosystem structure and function. This has led to reduced herbaceous production leading to lower forage production, greater bare soil, and higher erosion rates. Consequently, although only 4 percent of the Rio Grande’s average annual run-off originates in the RPW, over 70 percent of the Rio Grande’s average annual suspended-sediment load is derived from it. This sediment load is then deposited in Elephant Butte Reservoir, and has been a substantial contributor to the sedimentation and decreased capacity of the reservoir, which then impairs the quality and quantity of water available for production agriculture and domestic use.

The primary objectives of this project have been to assess the effects of prescribed grazing and brush management conservation practices on plant and soil communities, wildlife habitat, hydrologic processes, and erosion in the RPW, and to provide a foundation for future range management decisions. To this end, monitoring instrumentation and procedures have been put in place that permit the tracking of responses of the plant and soil biological communities to current ecological management practices. A commonly used practice in this system includes the control of woody species by herbicide application. To assess the impact of this practice, the research team set up a GPS defined grid of monitoring locations and measured before-and-after effects on plant canopy and basal cover, biomass production, as well as soil biological and physical characteristics. They collected pre-treatment measurements last fall, and post-treatment plant and soil community measurements will be collected at the end of this growing season.

The hydrological monitoring is aimed at tracking the runoff of water following precipitation events. This will provide a foundation for improving landscape-scale hydrological models for the RPW. For this purpose, six devices were constructed and installed on the research site in association with climate monitoring stations installed by the NRCS. These climate stations provide a suite of meteorological measurements including precipitation, temperature, and wind speed along with soil moisture and temperature readings at three depths (10, 20, and 50 centimeters). To measure runoff they constructed Upwelling Bernoulli tube monitoring devices out of four-inch Schedule 40 PVC pipe, with vented pressure transducer sensors installed to obtain water level depths within the devices with a resolution of two millimeters. Water depth readings are recorded as a function of time, and estimates of runoff rates can then be inferred and coupled with precipitation event data. This information allows for the establishment of spatially distributed runoff patterns across the installation sites. They are monitoring runoff throughout the growing season, and will use the field-collected data to achieve a greater understanding of how upland conservation practices truly impact the hydrology of the system.

The results of this study should prove useful for state and federal agencies, as well as private landowners, because it will provide a means for evaluating range improvement methodologies, and specifically the impacts those practices may have on the hydrology of the associated systems. Linking upland conservation practices to the quantity and quality of water flowing through those areas will increase our knowledge of potential benefits to water supplies downstream. If conservation practices on rangelands within the RPW can decrease potential runoff and sediment load, the improvement of the ecological and hydrological stability would provide valuable water resources for the state of New Mexico and the borderlands.

The Udall family settled in St. John’s, Arizona in the 1880s. The family farmed for generations, and “water was the lifeblood of that community,” according to Brad. Growing up in the Southwest in the 1950s and ‘60s in political families, Tom and Brad described how they learned first-hand about the water supply challenges our region has faced.

Although he is remembered for his great conservation legacy, Mo first made a name for himself in Congress in the 1960s with the authorization of the Central Arizona Project (CAP). A 336-mile diversion of Colorado River water that fuels Arizona with 1.6 million acre-feet annually, CAP has been instrumental in Arizona’s growth over the last several decades. As Tom put it, “you just couldn’t get elected in Arizona” in the 1960s unless you supported CAP.

Under his tenure at Interior, Stewart oversaw the completion of the Glen Canyon Dam and creation of the Lake Powell reservoir. This Bureau of Reclamation project provides water and low-cost electricity for the Southwest – but it came at a substantial environmental cost. Tom recalled that his family rafted the Colorado River in 1967, just before the dam was shut, and that his father began to develop regrets about the dam project.

Around that time, Mo had even championed damming the Grand Canyon. But after Stewart’s raft trip ‒ and with the growing awareness of the environmental issues ‒ Mo and Stewart’s thinking evolved. They sought to better research and understand the environmental consequences of big projects ‒ and they concluded that filling the canyon and forever changing its ecosystem would be too great a price to pay.

Tom said he brings this approach to the Senate ‒ balancing economic development in New Mexico with conservation of our natural and cultural resources. He is a leader in Congress, fighting for smart water strategies, policies to harvest and develop clean energy, and to prevent global warming.

Brad studies the Colorado River, and recently published a paper with climate scientist Jonathan Overpeck in Water Resources Research, assessing the impact of climate change on the approximately 20 percent reduction in flow of the river between 2000 and 2014.¹  They conclude that the reduction cannot be explained entirely by drought, and that the 2 degree Fahrenheit increase in temperature in the region accounts for 30 percent of the reduction. They project a further 20 percent temperature-induced reduction in flow by mid-century, and 35 percent temperature-induced reduction by the end of the century.

Brad’s proposal: Go to zero greenhouse gas emissions as soon as possible.

According to Tom, there was political will in Congress at the beginning of President Obama’s first term to address climate change. The House passed a cap and trade program, but it could not pass the Senate. The White House dropped its push for climate change policy and prioritized health care instead. And after the 2010 election, Congress had become so divided, there were no longer enough lawmakers dedicated to tackling major legislation to prevent global warming.

Tom and Brad agreed that our campaign finance system – which allows super wealthy individuals and corporations to contribute unlimited and undisclosed or “dark” political contributions – has significantly blocked efforts to pass major climate legislation, and that part of the solution is to reform campaign finance laws to prevent special interests from dominating elections. Tom said he has fought the influence of big “dark money” since he first was elected to office.

Tom ended by paraphrasing Aldo Leopold’s observation: “When we see land as a community to which we belong, we may begin to use it with love and respect.” And Brad followed with an observation from Stewart: We need to understand that, “. . . we are not outside of nature, but are part of it.”

The presentation was a lively and informative dialogue from two cousins who have the benefit of decades of their fathers’ experience and decades of their own.

¹Udall, B. and J. Overpeck (2017), The twenty-first century Colorado River hot drought and implications for the future, Water Resour. Res., 53, 2404–2418, doi:10.1002/2016WR019638.

In 2013, Dr. González-Pinzón received a PhD in water resources engineering from Oregon State University. He also earned an MS in water resources engineering from the National University of Colombia, and a BS in biosystems engineering with an emphasis in water resources, also from the National University of Colombia.

After joining the UNM faculty in 2014, Dr. González-Pinzón, received an NM WRRI grant to estimate catchment-averaged precipitation and evapotranspiration rates in New Mexico (NM WRRI TCR#371). He has also advised several NM WRRI student grant recipients from UNM over the past four years including Cameron Herrington, Vanessa Garayburu, James Fluke, and Betsy Summers.

Dr. González-Pinzón recently noted that NM WRRI student funding contributed to the collection of preliminary data that helped to secure two National Science Foundation grants. Currently he is leading a team of researchers from UNM, University of Colorado (Dr. Michael Gooseff), Colorado School of Mines (Dr. Kamini Singha) and Colorado State University (Dr. Timothy Covino) on a three-year project, Collaborative Research: How do interactions of transport and stoichiometry maximize stream nutrient retention? This research will explore, by both field and modeling methodologies, their hypotheses on the dynamical interactions of sources and sinks of carbon, oxygen, and nutrients in diverse stream compartments, and the contribution this makes to the retention and export of nutrients in stream. The research team will include numerous graduate students.

In a second NSF funded project, Dr. González-Pinzón will work with Dr. David Van Horn from UNM’s Biology Department (Dr. Van Horn himself was an NM WRRI student grant recipient in 2005). This project will monitor water quality parameters and dissolved organic carbon along the Jemez River-Rio Grande continuum.

Congratulations to Dr. González-Pinzón and his students for their success in securing significant support for their research.