What aspect of California's Central Valley Project causes concern for environmentalists?

Environmentalists express concern about the impact of California's Central Valley Project on local wildlife habitats primarily due to the extensive alteration of natural ecosystems that the project entails. The Central Valley Project, designed to manage and distribute water across the state, modifies the natural hydrology of the region, which can lead to habitat loss and degradation for various flora and fauna.

The infrastructure associated with the project, such as dams and reservoirs, disrupts native habitats, particularly wetlands and riparian zones, which are crucial for a variety of species. Additionally, the alteration of water flow and availability can have cascading effects on the ecosystem, affecting food sources and breeding grounds for wildlife, potentially leading to declines in populations of certain species.

While other factors such as water supply limitations, operational costs, and fish migration issues are all relevant and carry some weight in environmental discussions, the direct impact on wildlife habitats encapsulates a broader range of concerns regarding biodiversity and ecosystem health, making it a significant focal point for environmental advocacy in relation to the Central Valley Project.