IID Announces Public Review and Comment Period on Proposed Large Load Tariff to Protect Ratepayers and Grid Reliability

-Editorial 

The Imperial Irrigation District (IID)  announced a proposed Large Load Tariff for consideration by the IID Board at its meeting on Friday, May 15, 2026. The tariff will be available for a 30-day public review and comment period. The proposed tariff would require new large electric loads to fully fund the infrastructure, power supply and system upgrades required to serve them without shifting costs or risks onto existing customers.

IID’s responsibility is to evaluate the electrical grid and determine whether potential large loads can be served safely and reliably. To fulfill these responsibilities, the District must also establish technical, financial and operational requirements for service and ensure that all regulatory and compliance obligations for the provision of electrical service are satisfied. IID is not a land-use, zoning or siting authority. Cities and counties determine whether projects are approved or built.

The proposed tariff, being presented to the IID Board of Directors on May 15, is intended to establish a transparent and nondiscriminatory approach for evaluating large electric service requests, including potential data centers and other high-demand industrial loads. The policy is designed to ensure that existing IID customers do not subsidize large private developments.

Like utilities across the United States, IID has experienced increased interest from prospective large-load customers whose service needs may require substantial transmission, distribution, generation, and system infrastructure upgrades. To date, IID has received nine large-load proposals or inquiries at varying stages of evaluation.

The proposed tariff creates a standardized approach for evaluating those requests, including study funding requirements, minimum demand and energy obligations, long-term service commitments, collateral requirements, and full cost-recovery mechanisms.

The tariff applies to customers requesting 20 megawatts or more of electric demand with a proposed capacity factor of greater than 85%. It requires completion of IID’s interconnection and technical review processes, payment of actual study costs, execution of a customer reimbursement agreement, execution of an electric service agreement, and execution of a special facilities agreement addressing the infrastructure necessary for IID to reliably serve the customer. It also includes financial safeguards such as deposits, collateral requirements, minimum contract terms, and exit fees intended to protect existing customers from financial exposure and ensure that project-related costs remain the responsibility of the requesting customer. 

The proposed tariff reflects several months of technical, financial, and legal review focused on protecting IID customers while maintaining reliable electric service. IID has a legal obligation to evaluate eligible service requests fairly and in a nondiscriminatory manner, but that does not mean existing customers should carry the risk. 

IID hired expert consultants, reviewed how leading utility departments across the nation handle similar large-load requests, and developed an approach that allows IID to rigorously evaluate transmission constraints, long-term power supply obligations, resource adequacy impacts, and overall system reliability before any commitment to serve is made.

IID is releasing the proposed tariff for a 30-day public comment and stakeholder review period. Following the comment period, IID staff will evaluate feedback, consider revisions and return to the Board at a future meeting with a final proposed tariff for consideration and possible approval.

Public comments may be submitted by email to Stakeholder@IID.com or by mail to:

General Counsel

Imperial Irrigation District

333 E. Barioni Boulevard

PO Box 937

Imperial, CA 92251

The proposed Large Load Tariff is available at: www.iid.com/proposedtariff.