How Sustainable are Engineered Rivers in Arid Lands?

Jurgen Schmandt,Gerald R North,George H Ward

doi:10.13044/j.sdewes.2013.01.0006

Abstract

Engineered rivers in arid lands play an important role in feeding the world’s growing population. Each continent has rivers that carry water from distant mountain sources to fertile soil downstream where rainfall is scarce. Over the course of the last century most rivers in arid lands have been equipped with large engineering structures that generate electric power and store water for agriculture and cities. This has changed the hydrology of the rivers. In this paper we discuss how climate variation, climate change, reservoir siltation, changes in land use and population growth will challenge the sustainability of engineered river systems over the course of the next few decades. We use the Rio Grande in North America, where we have worked with Mexican and American colleagues, to describe our methodology and results. Similar work is needed to study future water supply and demand in engineered rivers around the world.

Highlights

Important rivers throughout the world share these characteristics: The headwaters are fed by snowpack or rainfall in the mountains
Population growth will force increased water allocation to urban use. This raises important questions: How will reduced water supply and increased water demand impact river basins? Can irrigated agriculture do more with less? How can water managers cope with expected shortfalls? How sustainable are engineered rivers in arid lands? — The example of the Rio Grande, a heavily engineered river in arid lands, provides initial answers to these questions
We examine three physical factors that determine future surface water supply: climate variation, climate change and reservoir sedimentation

Summary

Introduction

Important rivers throughout the world share these characteristics: The headwaters are fed by snowpack or rainfall in the mountains. In our study we estimate future surface water supply from the largest reservoirs in the basin — Elephant Butte, Amistad and Falcón — and water demand in the major socio-economic sub-basins — Paso del Norte and Lower Rio Grande Valley. The reservoir serves as the main hydrological structure of the federal Rio Grande Project that supports irrigated agriculture in southern New Mexico and West Texas.

Results

Conclusion