California Code, Public Utilities Code - PUC § 16479

If the Board of Directors of the Tahoe City Public Utility District or of the North Tahoe Public Utility District determines to use all or any portion of a surplus remaining in the improvement fund from any assessment proceeding to improve the sewer system within district's jurisdiction in accordance with the provisions of subdivision (c) of Section 10427 of the Streets and Highways Code, all of the surpluses to be used for the maintenance of the improvements may be transferred by the legislative body to a single fund for the maintenance and operation of the sewer system without regard to the proportion of the funds so created attributable to each proceeding from which the surplus arose.

The board of directors shall transfer to such single fund the same percentage of the surplus from each improvement fund.  The fact that in one or more of such improvement funds no surplus exists shall not prevent the board of directors from proceeding pursuant to this section as to all improvement funds in which a surplus does exist if a surplus of no less than 2 1/2 percent of the total cost exists in no less than 75 percent of such funds.

This section, applicable only to the Tahoe City Public Utility District and the North Tahoe Public Utility District, is necessary because of unique and special fiscal management problems of improvement districts in the Lake Tahoe Basin.