Cal. Sts. & High. Code § 10204.5

In preparing the report in which assessments are apportioned pursuant to subdivision (e) of Section 10204, the person or board to whom the improvement is referred by the legislative body may presume that facilities which are required to meet the needs of future residents of an area, as indicated by a general or specific plan for the area, will benefit undeveloped and underdeveloped property within the area. If the legislative body adopts the report, that presumption shall be conclusive.