contributors - biologists, ecologists, geomorphologists, historians, hydrologists, lawyers, and political scientists - weave together threads from their diverse perspectives to reveal the processes that shape the past, present, and future of the San Pedro's riparian and aquatic ecosystems. They review the biological communities of the San Pedro and the stream hydrology and geomorphology that affects its riparian biota. They then look at conservation and management challenges along three sections of the San Pedro, from its headwaters in Mexico in its confluence with the Gila River, describing legal and policy issues and their interface with science; activities related to mitigation, conservation, and restoration; and a prognosis of the potential for sustaining the basin's riparian system." "Complemented by a foreword written by James Shuttleworth, these chapters demonstrate the complexity of the San Pedro's ecological and hydrological conditions, showing that there are no easy --

In prehistoric times, the Santa Cruz River in what is now southern Arizona saw many ebbs, flows, and floods. It flowed on the surface, meandered across the floodplain, and occasionally carved deep channels or arroyos into valley fill. Groundwater was never far from the surface, in places outcropping to feed marshlands or ciénegas. In these wet places, arroyos would heal quickly as the river channel revegetated, the thriving vegetation trapped sediment, and the channel refilled. As readers of Requiem for the Santa Cruz learn, these aridland geomorphic processes also took place in the valley as Tucson grew from mud-walled village to modern metropolis, with one exception: historical water development and channel changes proceeded hand in glove, each taking turns reacting to the other, eventually lowering the water table and killing a unique habitat that can no longer recover or be restored. Authored by an esteemed group of scientists, Requiem for the Santa Cruz thoroughly documents this river—the premier example of historic arroyo cutting during the late nineteenth and early twentieth centuries, when large floodflows cut down through unconsolidated valley fill to form deep channels in the major valleys of the American Southwest. Each chapter provides a unique opportunity to chronicle the arroyo legacy, evaluate its causes, and consider its aftermath. Using more than a collective century of observations and collections, the authors reconstruct the circumstances of the river’s entrenchment and the groundwater mining that ultimately killed the marshlands, a veritable mesquite forest, and a birdwatcher's paradise. Today, communities everywhere face this conundrum: do we manage ephemeral rivers through urban areas for flood control, or do we attempt to restore them to some previous state of perennial naturalness? Requiem for the Santa Cruz carefully explores the legacies of channel change, groundwater depletion, flood control, and nascent attempts at river restoration to give a long-term perspective on management of rivers in arid lands. Tied together by authors who have committed their life’s work to the study of aridland rivers, this book offers a touching and scientifically grounded requiem for the Santa Cruz and every southwestern river.

Typical development in the American Southwest often resulted in scraping the desert lands of the ancient living landscape, to be replaced with one that is human-made and dependent on a large consumption of energy and natural resources. This transdisciplinary book explores the natural and built environment of this desert region and introduces development tools for shaping its future in a more sustainable way. It offers valuable insights to help promote ecological balance between nature and the built environment in the American Southwest-and in other ecologically fragile regions around the world.