Climate Change Connections: New Mexico (Rio Grande)
Climate change is impacting all regions and sectors of the United States. The State and Regional Climate Change Connections resource highlights climate change connections to culturally, ecologically, or economically important features of each state and territory. The content on this page provides an illustrative example. As climate change will affect each state and territory in diverse ways, this resource only describes a small portion of these risks. For more comprehensive information about regional climate impacts, please visit the Fifth National Climate Assessment and Climate Change Impacts by Sector.
On this page:
Introduction: The Rio Grande—A Lifeblood in the Southwest
The fourth longest river in the United States, the Rio Grande, stretches nearly 1,900 miles across the Southwest and provides a vital water resource in the region.1 After running from the San Juan Mountains through southern Colorado and the entire length of New Mexico, the river then forms the southern boundary between the United States and Mexico until it reaches the Gulf of America.
For thousands of years, the river has been a lifeblood supporting the diverse Indigenous communities in the Rio Grande Valley. Changing river and drought conditions have been defining factors in settlement and agriculture across the region. Many Indigenous Pueblo communities are located along or near the river. Vast amounts of agricultural land in New Mexico and Texas depend on the river’s water supply for irrigation.1,2 In total, around three-quarters of the Rio Grande’s water flow is diverted for use in agriculture.3 Nearly 6 million people, including those in major cities like Albuquerque and Las Cruces, rely on the river as one of their primary sources of water.4,5
New Mexico, like much of the American Southwest, has an arid climate characterized by low levels of precipitation.6 The Rio Grande is fed by mountain snowpack at its headwaters and by rainfall throughout its watershed. Given the seasonal and annual variations in precipitation, the river has periods of both high and low flow, with portions drying up during droughts or large stretches overtopping its banks due to a sudden rush of rain.1 The animals and plants living in and around the Rio Grande have adapted to the variable precipitation. Native cottonwood trees send out seeds in coordination with annual flooding, which allows the seeds to germinate in the damp and fertile recently-flooded soil.7 The silvery minnow, an endangered species, spends much of its time in shallow, slow-moving parts of the river and tends to spawn in spring in response to meltwater.8
Multiple factors impact the river’s water supply as it moves downstream.9 Given that the river stretches across multiple state and international boundaries, the river faces competing demands for its water. These demands can at times exceed supply. There are ongoing negotiations between state governments, the federal governments of the United States and Mexico, local water utilities, and Indigenous groups about how to apportion and manage the river. Levees, dams, and other structures, which manage the river for agricultural, industrial, and municipal uses, also alter the river’s natural movement. Climate change is expected to further exacerbate supply and demand imbalances in the region.10
Climate Impacts: Changing Precipitation Patterns, Warming Temperatures, and Drought Can Impact River Flows
Climate change can impact snowpack, which is the amount or thickness of snow that accumulates on the ground, by altering both precipitation patterns and winter temperatures.11 In a warming climate, more precipitation will be expected to fall as rain rather than snow in most areas, reducing the extent and depth of snowpack. Higher temperatures cause snow to melt earlier, which in turn affects the timing and availability of water.
The Rio Grande is a snowmelt-driven system, with up to 75 percent of its water coming from the seasonal snowpack in the Colorado mountains.12 Snowpack, built up from snowfall accumulated over the winter, melts and feeds into the river system during spring. Low levels of winter precipitation overall lead to a “dry” snow drought, while warmer temperatures that cause winter precipitation to fall as rain instead of snow can cause a “warm” snow drought. Both types of snow drought can affect the mountain snowpack that feeds the Rio Grande.13 There are already ongoing, notable, and consistent decreases in snowpack in the mountains across southern Colorado.11 Regional decreases in snowpack season length can affect the timing and availability of meltwater.11
The Rio Grande is partly replenished by rainfall, particularly during the summer monsoon season. Precipitation in New Mexico has historically been highly variable and difficult to predict. Some areas of the state receive half of their annual rainfall during monsoon season.6 Cumulative precipitation has varied widely in the region, with significant differences from year to year and notable wet and dry spells lasting multiple years and even decades. In New Mexico, springtime precipitation is projected to continue to decrease, which could put more strain on water supplies.6
In addition, periods of drought, an already common phenomenon in the Southwest, are expected to become more intense due to climate change.10 Climate change has caused average temperatures to rise, which in turn has caused the Earth’s water cycle to speed up, increasing in the rate at which water evaporates from soil and transpires from plants. An increase in evapotranspiration makes more water available in the air for precipitation but contributes to drying over some land areas, leaving less moisture in the soil. While the Southwest and the Rio Grande experience natural variations from year to year, climate change is projected to further stress water supplies.14 Climate change is amplifying drought conditions and leading to reduced flows in the Rio Grande and other western rivers, such as the Colorado.10 In 2022, for the first time in nearly 40 years, a portion of the Rio Grande in Albuquerque ran dry.1 Scientists predict future decreases in the volume of water in the Rio Grande, which would make it challenging for current reservoir storage to meet water demands.15,16
Taking Action: The River in a Changing Climate
Addressing climate change requires reducing greenhouse gas emissions while preparing for and protecting against current and future climate impacts. Communities, public officials, and individuals in every part of the United States can continue to explore and implement climate adaptation and mitigation measures. Climate change is projected to further reduce flows into the Rio Grande, impacting the people who rely on the river and the region’s natural ecosystems. Stakeholders in New Mexico are taking steps to thoughtfully manage water resources, including:
- Watershed management. In an already arid region, water conservation has always been important and climate change is motivating further conservation efforts. The state of New Mexico released a 50-Year Water Action Plan in 2024, identifying water conservation as a key priority along with new water supplies and watershed protection.17 The state also identified goals for implementing a statewide public education campaign about how individuals can conserve water, as well as increased incentives for agricultural conservation.
- Water conservation measures. At municipal levels, improving the efficiency of water delivery and storage systems can have a major impact on water conservation. At all levels, fixing and reducing leaks is an important and straightforward way to conserve water resources. For educators, the state of New Mexico Interstate Stream Commission offers a water conservation curriculum. EPA highlights water-saving opportunities for everyone through the WaterSense program.
To learn more about climate change impacts in New Mexico and the Southwest region, see Chapter 28 of the Fifth National Climate Assessment.
Related Resources
- EPA Climate Indicators: Snowpack
- EPA Climate Indicators: Temperature and Drought in the Southwest
- New Mexico State Climate Summary 2022 (NOAA)
References
1 Pratt, S. E. (2022, August 23). Rio Grande runs dry, then wet. NASA Earth Observatory; NASA Earth Observatory. Retrieved July 18, 2023, from https://earthobservatory.nasa.gov/images/150244/rio-grande-runs-dry-then-wet
2 U.S. Bureau of Reclamation. (n.d.). Rio Grande Project. Projects and Facilities. Retrieved December 13, 2023, from https://www.usbr.gov/projects/index.php?id=397
3 U.S. Bureau of Reclamation. (2021). Rio Grande Basin SECURE Water Act 9503(c) report to Congress. U.S. Department of the Interior. https://www.usbr.gov/climate/secure/docs/2021secure/basinreports/RioGrandeBasin.pdf
4 Albuquerque Bernalillo County Water Utility Authority. (n.d.). San Juan-Chama Project. Albuquerque Bernalillo County Water Utility Authority. Retrieved December 13, 2023, from https://www.abcwua.org/your-drinking-water-san-juan-chama-project/
5 City of Las Cruces. (n.d.). FAQs. City of Las Cruces. Retrieved December 13, 2023, from https://www.lascruces.gov/Faq.aspx?QID=126
6 Frankson, R., Kunkel, K. E., Stevens, L. E., & Easterling, D. R. (2022). New Mexico state climate summary 2022 (NOAA Technical Report NESDIS 150-NM). NOAA National Environmental Satellite, Data, and Information Service. https://statesummaries.ncics.org/chapter/nm/
7 Smith, D. M., & Finch, D. M. (2017). Climate change and wildfire effects in aridland riparian ecosystems: An examination of current and future conditions (General Technical Report RMRS-GTR-364). U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. https://doi.org/10.13140/RG.2.2.24201.44649
8 U.S. Fish and Wildlife Service. (n.d.). Rio Grande silvery minnow. Retrieved June 19, 2024, from https://www.fws.gov/species/rio-grande-silvery-minnow-hybognathus-amarus
9 Miller, O. L., Putman, A. L., Alder, J., Miller, M., Jones, D. K., & Wise, D. R. (2021). Changing climate drives future streamflow declines and challenges in meeting water demand across the southwestern United States. Journal of Hydrology X, 11, 100074. https://doi.org/10.1016/j.hydroa.2021.100074
10 White, D. D., Elias, E. H., Thomas, K. A., Bradatan, C. E., Brunson, M. W., Chischilly, A. M., Enquist, C. A. F., Fisher, L. R., Froehlich, H. E., Koebele, E. A., Méndez, M., Ostoja, S. M., Steele, C., & Vanos, J. K. (2023). Ch. 28. Southwest. In A. R. Crimmins, C. W. Avery, D. R. Easterling, K. E. Kunkel, B. C. Stewart, & T. K. Maycock (Eds.), Fifth National Climate Assessment. U.S. Global Change Research Program. https://doi.org/10.7930/NCA5.2023.CH28
11 EPA. (2022). Climate change indicators: Snowpack. Retrieved December 16, 2023, from https://www.epa.gov/climate-indicators/climate-change-indicators-snowpack
12 Moeser, C. David., Chavarria, S. B., & Wootten, A. M. (2021). Streamflow response to potential changes in climate in the Upper Rio Grande Basin (USGS Numbered Series No. 2021–5138; Scientific Investigations Report). U.S. Geological Survey. https://www.usgs.gov/publications/streamflow-response-potential-changes-climate-upper-rio-grande-basin
13 NOAA National Integrated Drought Information System. (2023). Drought status update: Snow drought current conditions and impacts in the west. Drought.gov. Retrieved December 13, 2023, from https://www.drought.gov/drought-status-updates/snow-drought-current-conditions-and-impacts-west-2023-12-06
14 Dettinger, M., Udall, B., & Georgakakos, A. (2015). Western water and climate change. Ecological Applications, 25(8), 2069–2093. https://doi.org/10.1890/15-0938.1
15 Elias, E. H., Rango, A., Steele, C. M., Mejia, J. F., & Smith, R. (2015). Assessing climate change impacts on water availability of snowmelt-dominated basins of the Upper Rio Grande basin. Journal of Hydrology: Regional Studies, 3, 525–546. https://doi.org/10.1016/j.ejrh.2015.04.004
16 Holmes, R. N., Mayer, A., Gutzler, D. S., & Chavira, L. G. (2022). Assessing the effects of climate change on middle Rio Grande surface water supplies using a simple water balance reservoir model. Earth Interactions, 26(1), 168–179. https://doi.org/10.1175/EI-D-21-0025.1
17 New Mexico Office of the Governor. (2024). 50-Year Water Action Plan. https://www.nm.gov/wp-content/uploads/2024/01/New-Mexico-50-Year-WaterAction-Plan.pdf