Book excerpt: "Over the millennia, the drainageway we now call the Santa Cruz River has seen many ebbs, flows, and floods. Throughout its long history, the river has meandered. It has flowed on the surface. It has carved deep fissures, and it has widened and narrowed.As readers of Requiem for the Santa Cruz learn, these are events that also have taken place in historic times. Authored by an esteemed group of scientists, Requiem for the Santa Cruz thoroughly documents this river, which flows through Tucson, Arizona, as a prime example of arroyo cutting, a process where heavy rains cut down through rock to create deep channeling. Each chapter provides a unique opportunity to chronicle the arroyo legacy, evaluate its causes, and consider its aftermath. Using more than a century of observations and collections, the authors reconstruct the physical, biological, and cultural circumstances of the river's entrenchment, widening, and subsequent partial filling. Today, communities everywhere face this conundrum: do we manageephemeral rivers through urban areas for flood control, or do we attempt to restore them to some previous state of naturalness? Requiem for the Santa Cruz carefully explores the channel-change legacy, the efficacy of attempts to stabilize it, and the 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 arid-land rivers, this book offers a touching and scientifically grounded requiem for the Santa Cruz and every southwestern river"--