In the event of a shortage in water supply, within the meaning of Article 18(a) of the standard water supply contract between the department and the state water supply contractors, the determination of whether to count, in whole or in part, the reduced demand from future conservation programs described in Section 11970 in the allocation of deficiencies among contractors shall be based on a project-by-project evaluation taking into consideration such factors as any limitation on the use of the water from the facilities and whether the sponsoring contractor has access to project water from the delta as an alternate to those facilities.