What pest interfered with water transmission systems in California?

The correct choice is based on the significant impact that crabs and clams can have on water transmission systems in California. These organisms can cause various physical and biological disruptions in aquatic environments. For instance, certain freshwater or estuarine clams can settle and grow in pipelines and infrastructure, leading to blockages. In some cases, they can alter the flow of water by creating obstructions and can also contribute to the deterioration of materials used in water systems.

Understanding the behavior of these pests is crucial for managing and mitigating their effects on water transmission systems. Given the economic and environmental implications, particularly in an area where water management is vital due to its arid climate, addressing the presence of crabs and clams is essential for maintaining the efficiency and reliability of water systems.