Abstract: A combination water meter comprises a main meter which can be connected to a water main for determining larger amounts of water flow and to an auxiliary meter which is disposed in a bypass conduit for determining smaller amounts of water flow. An on-off valve insert, which opens the passageway through the water main when a specified pressure is reached, is disposed in series with the measurement insert of the main meter, and the measurement insert of the main meter as well as the auxiliary meter are disposed in a housing having a partition which divides the housing into an upstream chamber and a downstream chamber and has an opening between the two. The lid of the housing and the inserts are connected in such a manner that they can be dismantled as a unit. The partition is fastened to and preferably integrally molded with the lid and sealed with respect to the housing by means of a gasket.