Section R. 325.11105 - Capacity of distribution system; fire hydrants; inadequately sized watermainsRule 1105.
(1) Distribution systems shall have sufficient capacity to meet peak demands, including fire flow demands where fire protection is provided, while continuously maintaining a minimum of 35 psi throughout the distribution system under normal operating conditions and 20 psi throughout the distribution system during emergencies such as fire fighting.(2) The department may prohibit installation of fire hydrants where watermain capacity, system source capacity, storage capacity, or pressure is inadequate to sustain fire flow demands in addition to normal user demands.(3) Replacement of inadequately sized watermains with watermains of the same size is prohibited.Mich. Admin. Code R. 325.11105