Water Resource Knowledge in Río Bravo Basin

Introduction

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The Rio Grande/Rio Bravo Basin (hereinafter referred to as the Rio Grande) is a transboundary basin, with the Rio Grande forming the border between the United States and Mexico for approximately 2,034 km. The waters of the Rio Grande serve as a critical drinking source for 13 million people, connecting numerous population centers representing diverse backgrounds and cultures along its length. Cross-border ecosystems and communities make water management strategies particularly challenging. With different regulations and societal interests in the two countries, developing effective water-management strategies is challenging and requires the coordination of diverse interested parties representing different government agencies, institutions, and stakeholder groups with varying and sometimes conflicting objectives. To better evaluate the human and environmental water needs (environmental flows) of this constrained river system, an improved understanding of past and present water management objectives, policies, allocation practices, and water use is needed. 

Key Issues Addressed

The Rio Grande Basin is a highly constrained river system that has undergone habitat degradation as a result of channel narrowing, loss of reliable streamflow, and the introduction of invasive species invasive species
An invasive species is any plant or animal that has spread or been introduced into a new area where they are, or could, cause harm to the environment, economy, or human, animal, or plant health. Their unwelcome presence can destroy ecosystems and cost millions of dollars.

Learn more about invasive species , with the near-extinction of endemic aquatic species one of the consequences. The multi-national, multi-state, and ecologically diverse nature of the Rio Grande Basin makes resource management a complex task. Although water-resource data and water-supply models exist for the different reaches of the basin, there have been no previous efforts to compile this information to make it easily accessible to water-resource managers or to integrate existing models into a holistic watershed decision-support tool. 

Project Goals

• Compile georeferenced water-related data for Rio Grande Basin
• Develop an inventory of modeling tools available to evaluate human and environmental water management objectives
• Assess applicability of available modeling tools for evaluating trade-offs between societal and environmental flow requirements to restore native ecosystems
• Identify information gaps that merit additional research and resources
• Describe promising future steps to integrate and improve existing systems models

Project Highlights

All in One Place: This project compiled data from hundreds of different sources, including datasets in Spanish, allowing researchers to quickly access previously dispersed water management information.

• Two-Step Approach: The research was divided into two main tasks. First, all relevant water-management data were collected, compiled, and georeferenced (spatially represented features on the Earth). Second, a thorough analysis of water-related modeling tools for the basin was conducted. Relevant water-management data were collected from different sources and merged into single vector files (shape files). For instance, multiple files for cities in Colorado, New Mexico, Texas, and the Mexican States were combined into a single file that includes all the cities for the entire basin. The same procedure was performed for many water-related features on the basin such as dams, rivers, water bodies, and natural protected areas.
• A Comprehensive Toolbox:This work provides water resource managers with an easily accessible and comprehensive inventory of existing tools that evaluate feedback from human and environmental water management strategies for the Rio Grande Basin across the United States and Mexico. A review of almost 60 water-supply models was performed, prioritizing modeling tools that address concerns of competing water uses and facilitate complex decision making in the Rio Grande Basin. This analysis includes a thorough review of the motivations and decision-making processes for which these tools were developed.
• Data Collection: A collection of geographic datasets of water-related elements on the Rio Grande Basin was made and categorized in the following topics: Boundaries and populated places; Hydrology and climate; Environmental; Land use and cover; and Water management. Data coming from different agencies is frequently found with different characteristics or formats and an important part of this work was to homogenize such differences when possible.
• Inspiring Efforts: This work inspired another geodatabase published in Nature, a highly respected and widely read journal.

Lessons Learned

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The Rio Grande is a single system and needs to be managed as such. Water management has become an important part of its history, underscoring the need to consider water information from both sides of the border to best address complex problems in the basin.

The results of this research show that there are a variety of models available to assist in planning activities across the basin. However, there were not enough models to cover the needs of the entire basin or with the necessary time-step (daily or hourly) for developing operational environmental flow targets (water that needs to be left in rivers to allow natural processes in aquatic ecosystems) in the basin.

Implementing an adaptive management strategy would help facilitate the evaluation and correction of environmental flow releases. Project researchers recommend moving from monthly planning models into weekly (or smaller) time-step models and operational models that mix surface water and hydraulic characteristics to account for other factors such as sediment concentration, water quality, and floodplain inundation.

Next Steps

• Another two-fold study is planned to estimate the daily natural flow regime from 1900-2015. This will help researchers better understand the evolution of the natural hydrology and native riverine ecosystems of the region and to characterize drought patterns and flood events.
• Researchers hope that this project serves as a strong foundation of literature review and data for future researchers working to solve the complex water-resource management issues of the Rio Grande Basin.

Funding Partner

South Central Climate Adaptation Science Center 

Resources

• USGS Project Page
• Plassin et al. (2020). “A socio-environmental geodatabase for integrative research in the transboundary Rio Grande/Río Bravo basin.” Scientific Data, 7(80).

Contacts

• Samuel Sandoval Solis, Ph.D., Principal Investigator, University of California-Davis: samsandoval@ucdavis.edu
• Jose Pablo Ortiz Partida, Graduate Student, University of California-Davis, and Climate and Water Scientist, Union of Concerned Scientists: jportiz@ucsusa.org

Case Study Authors

• Ilana Casarez, Student Hydrologist, Oklahoma-Texas Water Science Center: icasarez@usgs.gov
• Samuel Sandoval Solis, Ph.D.
• Jose Pablo Ortiz Partida

Suggested Citation

Casarez l., R., Sandoval, S., S., and Ortiz-Partida, J., P. (2020). “Assessing the State of Water Resource Knowledge and Tools for Future Planning in the Lower Rio Grande-Rio Bravo Basin.” CART. Retrieved from https://www.fws.gov/project/water-resource-knowledge-rio-bravo-basin.