Date of Award
Spring 5-22-2026
Document Type
Thesis
Degree Name
Master of Landscape Architecture (MLA)
Department
Landscape Architecture
First Advisor
Leeland McPhail
Second Advisor
German Pallares-Avitia
Abstract
National policies materialize in the United States-Mexico political divide, also known as the borderlands. Willow Canyon is a dissected land form inextricably linked to the Tijuana River watershed, forming with the adjacent landforms on both sides of the border one landscape. The Guadalupe Hidalgo Treaty¹, signed in 1848 by the US and Mexican governments, traced an arbitrary line across these landscapes, disregarding their relationship. The consequences of these actions are visible in the physical deterioration of the landscape and ecology, as the hydrological cycle has been modified. In the 1940’s, the picturesque flow of Willow Canyon was dissected by urbanization, creating North and South Canyons, which are also disconnected from the floodplain by the political divide. Given these multiple separations, the canyon no longer serves its hydrological function as a conduit between the headlands and the watershed’s floodplain, feeding the ecology. North Canyon is suffering from an excess of sediment deposition and is unable to release it into the adjacent estuary. This regime will lead to sediment buildup, creating a flat area. South Canyon is urbanized, with a concrete-lined channel that increases water velocity and sediment transport, further damaging North Canyon. Furthermore, it has affected the psychological landscape of the community and society, as the physical reinforcement of the political divide has deepened the separation of the people on both sides. While urban infrastructure brought modern amenities to the Tijuana community, such as piped water, sewage, and electricity, it came at the cost of sacrificing the canyon’s biodiversity, regularizing the land, and distancing the inhabitants from the local landforms in an attempt to homogenize the space. The community of Imperial Beach on the North side of the political divide was dislocated to make way for a military facility in the 1920’s. The military ended its operations in the 1960’s, leaving the land scarred, making it more difficult for the community to come into the area. By restoring the hydrological function of Willow Canyon, the community will reconnect with this forgotten landscape and be empowered to care for and steward both sides holistically as a unified landscape within the watershed. Willow Canyon will be restored in a phased approach by removing the concrete and introducing a nature-based solution incorporating soil bags along the banks of South Canyon. A comprehensive planting strategy on the North Canyon and a soil amendment program on the US side to prepare the soil for water infiltration.
Recommended Citation
Lopez Vazquez, Maria D., "Weaving Grounds: Connecting canyons and empowering borderland communities" (2026). Masters Theses. 1676.
https://digitalcommons.risd.edu/masterstheses/1676
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