Contesting rates or fees of water & sewerage services

First, petitioners failed to resort to the appropriate remedy. Under Section 12 of the MWSS Charter, it was the defunct Public Service Commission which had the exclusive original jurisdiction over all cases contesting the rates or fees of water and sewerage services, thus:

Sec. 12. Review of Rates by the Public Service Commission.- The rates and fees fixed by the Board of Trustees for the System (MWSS) and by the local governments for the local systems shall be of such magnitude that the Systems rate of net return shall not exceed twelve percentum (12%), on a rate base composed of the sum of its assets in operation as revalued from time to time plus two months operating capital. Such rates and fees shall be effective and enforceable fifteen (15) days after publication in a newspaper of general circulation within the territory defined in Section 2(c) of this Act. The Public Service Commission shall have exclusive original jurisdiction over all cases contesting said rates or fees. Any complaint against such rates or fees shall be filed with the Public Service Commission within thirty (30) days after the effectivity of such rates, but the filing of such complaint or action shall not stay the effectivity of said rates or fees. The Public Service Commission shall verify the rate base, and the rate of return computed therefrom, in accordance with the standards above outlined. The Public Service Commission shall finish, within sixty (60) calendar days, any and all proceedings necessary and/or incidental to the case, and shall render its findings or decisions thereon within thirty (30) calendar days after said case is submitted for decision.
In cases where the decision is against the fixed rates or fees, excess payments shall be reimbursed and/or credited to future payments, in the discretion of the Commission.

Indeed, petitioners have a plain and speedy remedy in the ordinary course of law as prescribed in Section 12 above. They cannot avail of certiorari as a substitute for that plain and speedy recourse. The writ of certiorari and prohibition may be availed of only when there is no appeal, or any plain, speedy, and adequate remedy in the ordinary course of law. (G.R. No. 173044; December 10, 2007)