Alison B. Hirsch, PhD, FAAR, ASLA is a landscape historian and designer. She is Associate Professor of Landscape Architecture & Urbanism at University of Southern California (USC), where she founded and directs the Landscape Justice Initiative (LJI), which serves as a platform to address questions of environmental, spatial, and climate justice at local and systemic scales. One of Hirsch’s primary research projects with LJI centers on rural communities in California’s Central Valley and the vast inequalities inscribed in that landscape reshaped by 150 years of industrial agriculture. She was the 2017–2018 Prince Charitable Trusts/Rolland Rome Prize Fellow at the American Academy, a 2020–2021 LAF Fellow in Leadership+Innovation, and a 2024–2025 Shapiro Center for American History & Culture Fellow at the Huntington Library, where she is completing a book on her work in the lower Central Valley, most specifically on the entangled histories, presents, and futures of the Tulare Lake and the historically Black town of Allensworth, CA. Formerly, Hirsch was Director of the Landscape Architecture & Urbanism program at USC (2019–2023) and co-founder/partner at foreground design agency (2011–2023) with which she completed a number of activist speculative and built works. Author of numerous articles and chapters, Hirsch wrote City Choreographer, about the creative process landscape architect Lawrence Halprin developed with his wife, the dancer and choreographer Anna Halprin (University of Minnesota), and co-edited a volume of essays by James Corner, The Landscape Imagination (Princeton Architectural Press).

Southern California is a landscape of ecological abundance, cultural complexity, and climatological extremes. Prior to Spanish arrival, what became known as the Los Angeles Basin and the broader mountains, forests, deserts, coasts, and wetlands were inhabited and stewarded by Native peoples with ancestral knowledge of the dynamic biophysical systems that make up the richness of the region. Beginning with the arrival of the Spanish, as the land and people of California were colonized, so too were its waters—resulting in a hydrological system that is now among the most highly engineered on the planet. Over the 19th and 20th centuries, increasingly complex hydraulic infrastructures—dams, aqueducts, and concrete channels—enabled rapid urban growth, often privileging profit and private enterprise over ecological health and equity. The Los Angeles Aqueduct, completed in 1913, and the Colorado River Aqueduct, completed in 1941, redefined the metropolis, severing watersheds and fueling speculative expansion while marginalizing vulnerable communities. 

Parallel to this exploitation, visionaries, including Frederick Law Olmsted, Sr. and Olmsted Brothers, brought attention to natural and cultural resources that should not be lost to human development. The Olmsted-Bartholomew Plan of 1930 for Los Angeles proposed a resilient regional green infrastructure, linking hydrology, open space, and urban growth. Its shelving left the city fragmented, paved over, and hydrologically impaired. 

Today, climate change exacerbates the region’s historic vulnerabilities—drought, floods, wildfire, and inequitable risk exposure—demanding integrated, multi-benefit water planning. Recent efforts, from the Klamath River dam removal in Northern California to LA County’s Measure W, signal California’s shift toward watershed-based, restorative approaches. Landscape architects, with their systems thinking and cross-scalar design expertise, are central to these transformations. This gathering of practitioners, historians, engineers, and policymakers examines inherited conditions and emerging projects, demonstrating the profession’s critical role in addressing urban water challenges and shaping equitable, climate-resilient hydrological futures.