California Legal Brief

The Rule of Hiller v. Marin Municipal Water District is that challenges to water rate ordinances must be brought through validation proceedings within 120 days of adoption, and failure to participate in a water district's validation action bars all subsequent constitutional and substantive challenges to the rates, under Government Code section 53759's mandatory validation statute requirements.

Appeal from judgment after demurrer sustained without leave to amend in Superior Court, Marin County.

Plaintiff Appellant was Tove Hiller — a ratepayer who filed government claims alleging water rate violations of Proposition 218 and sought class action refunds.

Defendant Respondent was Marin Municipal Water District — the municipal water agency that adopted increased water rates through Ordinance No. 464 and filed a validation action.

The suit sounded in constitutional challenges to municipal water rates under Proposition 218. Hiller sought declaratory and injunctive relief, refunds, and mandamus relief claiming the District's tiered water rate structure violated constitutional cost-of-service requirements.

The key substantive facts leading to the suit were the District adopted Ordinance No. 464 on May 16, 2023, establishing water service rates effective July 2023 through June 2027 after conducting cost-of-service analysis, providing public notice, and holding hearings as required by Proposition 218. The District then filed a validation action in July 2023, obtained default judgment in October 2023 after no party contested it, while Hiller filed her separate challenge in September 2023.

The procedural result leading to the Appeal: The trial court sustained the District's demurrer without leave to amend, ruling that Hiller's claims were barred by the final judgment in the District's validation action under Government Code section 53759 and the validation statutes.

The key question(s) on Appeal: 1. Whether Government Code section 53759 requiring water rate challenges be brought under validation statutes conflicts with Proposition 218's constitutional protections; 2. Whether Hiller's due process rights were violated by lack of personal notice of the validation action; 3. Whether mandamus claims challenging water rates on constitutional grounds fall outside section 53759's validation requirements.

The Appellate Court held that Government Code section 53759 mandates all judicial challenges to water or sewer rate ordinances proceed under validation statutes, that notice by publication in validation actions satisfies due process even for parties who filed government claims, and that mandamus proceedings challenging rate ordinances constitute "judicial actions" subject to validation requirements, making Hiller's claims time-barred and procedurally foreclosed by the unchallenged validation judgment.

The case is inapplicable when a plaintiff timely files a reverse validation action before the agency files its validation proceeding, when a party timely appears and contests the agency's validation action within the statutory deadline, or when challenges involve billing errors or implementation defects rather than the validity of rate ordinances themselves.

The case leaves open whether different notice procedures might be constitutionally required in validation actions involving parties with known addresses and attorneys, the scope of challenges permitted under the companion statutes sections 53759.1 and 53759.2 effective January 1, 2025, and what constitutes sufficient grounds to distinguish constitutional challenges from rate validity determinations.