What is one method by which water rights are secured in California?

In California, securing water rights is primarily associated with the state's longstanding legal framework that includes riparian rights, which are based on land ownership adjacent to a water source. This means that landowners whose properties border a waterway have the right to use that water for reasonable purposes, provided that their use does not negatively impact other riparian users or the water source itself.

While the construction of the Shasta Dam is a significant engineering project that impacts water management in California, it does not directly secure individual water rights for users. Instead, it is a part of the broader infrastructure that helps manage water supply and distribution for various purposes, including agricultural, municipal, and environmental needs. The rights to use the water stored and controlled by such facilities are regulated and allocated by the state through comprehensive water law rather than being secured solely through the dam's construction.

The other choices, such as purchasing private water supplies or engaging in government-led water conservation plans, are methods related to acquiring or managing water, but they do not fundamentally establish water rights in the same way that riparian rights do. Therefore, focusing on riparian rights offers a more accurate understanding of how water rights are secured in California.