As used in this part, unless the context otherwise requires:
(1) “Housing trust fund” means a fund consisting of appropriations, reserves or dedications of any revenues except pension or retirement funds by a participating unit or units of local government, together with private and foundation sources of funds, all used for providing low income persons with safe and affordable housing;
(2) “Low income” means qualified persons or families who lack the amount of income which is necessary, as determined by the approved entity, to enable them without low interest financial assistance, to live in decent, safe and affordable dwellings without overcrowding; and
(3) “Unit or units of local government” means any city or county, separately or together, that sets up a program to establish a housing trust fund.