The principal activity of a district is defined as that activity for which the greatest amount of time and money is expended. Districts which are principally water, but which engage also in other activities, must account for the latter in terms of accounts prescribed in other articles.
The accounts
Revenue from Other Activities, and Expenses of Other Activities
indicate the positions of non-water revenues and expenses. In practice they would act as control accounts for prescribed accounts, or would be replaced by them.
This policy does not extend to balance sheet accounts. Multi-activity districts need maintain only the balance sheet accounts prescribed for the principal activity.
Cal. Code Regs. Tit. 2, § 1041.13