10 C.F.R. § 904.10 – Excess energy.

(a) If excess Energy is determined by the United States to be available, it shall be made available to the Contractors, in accordance with the priority entitlement of section 105(a)(1)(C) of the Hoover Power Plant Act (43 U.S.C. 619(a)(1)(c)). After the annual first- and second-priority entitlement to excess energy has been obligated for delivery, Western will make available one-third of the third-priority excess energy to the Arizona Power Authority, one-third to the Colorado River Commission of Nevada, and one-third to the California Contractors.
(b) Western will make available third-priority excess energy to the California Contractors based on the following formula:
F = 1/2 (A/B + C/D) (E); Where:
A = Contractor's allocated Capacity B = Total California allocated Capacity C = Contractor's allocated Firm Energy D = Total California allocated Firm Energy E = Third-priority Excess Energy available to California F = Contractor's third-priority Excess Energy
(c) The charge for all Excess Energy shall be the charge for Boulder Canyon Project Firm Energy existing at the time the Excess Energy is made available to the Contractor, including the appropriate Lower Basin Development Fund Contribution Charge.