Which division enforces the California Clean Water Act?

The State Water Resources Control Board is the division responsible for enforcing the California Clean Water Act. This agency plays a crucial role in managing the quality of the state's water resources, and its specific duties include regulating discharges into surface waters and ensuring that water quality standards are established and maintained. The board also oversees regional water quality control boards, which operate at a more localized level.

The Clean Water Act aims to restore and maintain the integrity of the nation’s waters by preventing point and non-point source pollution. Enforcement of this act involves implementing and enforcing regulations to protect water quality, issuing permits for discharges, and monitoring water quality throughout the state. The State Water Resources Control Board is therefore central in ensuring compliance with the provisions of the California Clean Water Act, making it the correct choice for this question.