Newhall Ranch in Valencia, California

Newhall Ranch is a proposed large scale master-planned community in an unincorporated portion of Los Angeles County along the Santa Clara River in the westerly portion of the Santa Clarita Valley. The development was conceived in the 1980s by Newhall Land, a land management company which created for the master community planning of nearby Valencia in the 1960s. During the decades the project has been in planning, it has faced legal actions, environmental concerns, and several changes in investors. The landmark California Environmental Quality Act, or CEQA, has been used to challenge the development even after it received planning approvals. While these lawsuits have been dismissed as merely tactics to block or delay the project by some, others claim the environmental law has led to a better-designed project while saving crucial habitat.

The required permits for the project describe how the work will fill in and alter more than 82 acres (33 ha) of flood plain and tributaries straddling one of the most dynamic river systems in southern California that has provided habitat for a wide array of native plants and animals. These include threatened and endangered fauna and flora, including the California condor, the California gnatcatcher, the southwestern willow flycatcher, the least Bell's vireo, the arroyo toad, the San Fernando Valley spineflower, and the threespine stickleback. The area has historically supplied humans with water, fish, and fertile farmland.

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