The voters of the City of Santa Monica adopted by initiative a rent control ordinance to be administered by D. The Charter Amendment gives D power to promulgate pertinent regulations, and to hear and determine complaints of violations of the system as administered. The Charter Amendment regulates the maximum allowable rents for controlled rental units and authorizes adjustments in maximum rents by way of both general and individual proceedings. Under section 1810, any violation of the Charter Amendment by a landlord constitutes a misdemeanor punishable by a fine of not more than $500 or imprisonment for not more than six months in county jail, or both. Under section 1811, the Board, tenants or landlords of controlled units may seek a court order enjoining violations of the rent control law. Section 1809 of the Charter Amendment permits a court action for damages. Section 1808 provides for review of the Board's decision. 'A landlord or tenant aggrieved by any action or decision of the Board may seek judicial review by appealing to the appropriate court within the jurisdiction.' Smith and Plevka, filed an administrative complaint asserting P had charged them excess rent. After a hearing officer made initial determinations and orders, all parties appealed to D. D held the tenants had been overcharged and awarded restitution of excess rent as well as treble damages. It expressly authorized Plevka to withhold $2,797.91. Smith was entitled to total recovery of $1,593.08. P filed a petition for writ of mandate, and other landlords were permitted to file a complaint in intervention. P argues that administrative adjudication of 'excess rents' violates, the judicial powers clause of the California Constitution. The trial court granted P's and interveners' motions for summary judgment and entered judgment granting the petition for writ of mandate. It ordered D to vacate the Plevka and Smith decisions, and declared former section 1809, subdivision (b), of the Charter Amendment 'invalid because it requires D to exercise judicial powers which fall within the ambit of Article VI, Section 1, of the California Constitution.' D appealed.