Drop 4 Plant Protection and Controls Project

The Imperial Irrigation District is implementing the Drop 4 Plant Protection and Controls Project at the Drop 4 Hydroelectric Facility in Holtville, California. The primary objective of this project is to replace and modernize obsolete protection and control systems to improve system reliability and maintainability. Specifically, the project involves replacing the existing GE Atlas Governor Control Systems for Units 1 and 2 with new Allen-Bradley PLC-based digital governor control systems. All work is required to be performed within the existing facility footprint, ensuring no new structures are built and no ground disturbance occurs. The scope of work includes the installation, programming, testing, and commissioning of new Governor Control Cabinets and a Plant Control Cabinet. These systems must maintain all existing operating functions, including unit operation, alarm and trip monitoring, plant cooling, water management, spill gate operation, and inter-unit communication. The project is classified under NAICS code 334513 and has been deemed categorically exempt from CEQA under Class 1, Section 15301 for existing facilities. Jeremy Brooks of the Environmental Compliance Unit serves as the primary point of contact for the agency.