Taking more farmland out of production and increasing irrigation efficiency on farms were two of the management options that could boost water flow in parts of the parched Rio Grande, according to the first report card for the Upper Rio Grande River basin, which was released Thursday.
“In some areas the basin is doing well, while in others it is struggling or even failing,” said Alexandra Fries, a program manager for the University of Maryland Center for Environmental Science (UMCES), which has produced report cards for river basins around the world. For this report, UMCES partnered with Audubon Southwest, the University of Massachusetts-Amherst, World Wildlife Fund, and local advocates.
The Upper Rio Grande basin stretches from the river’s headwaters in south-central Colorado through New Mexico to Texas, where it straddles the border with Mexico. The basin suffers from limited water availability due to climate change, interstate water-management issues, outdated infrastructure, and increased water demand from a growing population.
The researchers considered more than two dozen health metrics for the river basin that fell into four categories: governance and management, society and culture, water quality and quantity, and landscape and ecology. While the basin received a C overall, on some metrics, it scored much lower. For instance, annual low flow, which looks at the average flow for the driest seven-day period each year, received an F.
The report notes that while Colorado farmers in the basin made progress raising groundwater levels from 2013 to 2018 after instituting conservation efforts, that success has been erased by recent drought. The situation is worse downstream in New Mexico, where, due to reduced flow from Colorado, irrigation deliveries to farmers are diminished by early summer. In addition, Elephant Butte Reservoir in southern New Mexico — which could store enough water to irrigate almost 200,000 acres — has been nearly dry in recent years.
For the Rio Grande’s first 100 miles, in Colorado, the river remains close to its natural flow, according to the report card, but things get progressively worse as it travels through New Mexico. Below Elephant Butte Reservoir, for instance, “the natural heartbeat of the river is almost entirely obliterated and native fish and animal species are gone,” the report card said. By the time the river reaches Fort Quitman, Texas, on the border with Mexico, it is completely dry.
Casey Brown, a civil and environmental engineering professor at the University of Massachusetts-Amherst, helped create a model of options to improve management of the river and to mitigate the effects of climate change. While it’s likely the region will get warmer, Brown said, it’s unclear what precipitation patterns will be. “Variability in precipitation is going to be the key challenge,” he said.
According to Brown’s model, overall flow could be increased by fallowing a percentage of farm fields along the river, increasing agriculture irrigation efficiency, and easing regulations so that more water is stored in upstream reservoirs, where evaporation rates are lower.
Cleave Simpson, a farmer and Colorado state senator who worked on the report card, said the Colorado legislature recently allocated $30 million to help the Rio Grande Water Conservation District reduce groundwater pumping for agriculture. Simpson said that farmers also need to consider growing less-water-intensive crops, noting that he had grown hemp for the first time. “I used half the amount of water that I would have for other crops,” he said. “I think there’s room for this kind of innovation.”