A hydraulic installation for managing the water supply of a member such as a water-consuming device, a tap, a valve, a fire hydrant, said installation comprising at least one drinking water supply network and at least one rainwater conveyance network separate from each other, characterised in that - each rainwater conveyance network includes at least one rainwater storage tank, - each storage tank also comprising at least one level sensor able to emit a rainwater level signal in the corresponding tank, - said installation comprising a central unit for managing the water supply of said member, said member being separately connected to said drinking water supply network and to said rainwater conveyance network, said central unit being configured to receive said rainwater level signal(s) and operate valves of the installation configured to be remotely operable in order to control the network supplying rainwater to said member, so that - as long as said tank is filled with rainwater to a level greater than or equal to a threshold value, supplying said member with rainwater, and - using drinking water to supply said member on demand or when the level of said tank is below said threshold value, - said installation comprising at least one water metre and/or at least one flow metre for at least said rainwater conveyance network, - each water metre and/or each flow metre being connected to said central unit, which includes a wireless communication means for transmitting data, said central unit then being intended to be connected to a wireless communication network, wherein each water metre and/or each flow metre being configured for the wireless transmission of data measured by the latter, each water metre and/or each flow metre being then intended to be connected to a wireless communication network, and in that - said installation including a water supply management assembly comprising a main body forming a tank for receiving drinking water, this main body including a tubular casing delimiting an interior volume of diameter D, which is placed in the upper part of said assembly and is extended by a reduction of the main body, in fluid communication with said tubular casing, said reduction having a straight cross-section which is a portion of a semicircle of radius D/2, the outer surface of said reduction being rounded and placed in the extension of the outer surface of the tubular casing, said main body thus delimiting in the lower part of said assembly, a housing for receiving two pumps (17, 22) and portions of ducts, each pump (17, 22) being connected on the one hand to a portion of duct connected to a separate rainwater supply network and on the other hand to a portion of duct for the transport of rain or drinking water selected. - each rainwater conveyance network includes at least one rainwater storage tank, - each storage tank also comprising at least one level sensor able to emit a rainwater level signal in the corresponding tank, - said installation comprising a central unit for managing the water supply of said member, said member being separately connected to said drinking water supply network and to said rainwater conveyance network, said central unit being configured to receive said rainwater level signal(s) and operate valves of the installation configured to be remotely operable in order to control the network supplying rainwater to said member, so that - as long as said tank is filled with rainwater to a level greater than or equal to a threshold value, supplying said member with rainwater, and - using drinking water to supply said member on demand or when the level of said tank is below said threshold value, - said installation comprising at least one water metre and/or at least one flow metre for at least said rainwater conveyance network, - each water metre and/or each flow metre being connected to said central unit, which includes a wireless communication means for transmitting data, said central unit then being intended to be connected to a wireless communication network, wherein each water metre and/or each flow metre being configured for the wireless transmission of data measured by the latter, each water metre and/or each flow metre being then intended to be connected to a wireless communication network, and in that - said installation including a water supply management assembly comprising a main body forming a tank for receiving drinking water, this main body including a tubular casing delimiting an interior volume of diameter D, which is placed in the upper part of said assembly and is extended by a reduction of the main body, in fluid communication with said tubular casing, said reduction having a straight cross-section which is a portion of a semicircle of radius D/2, the outer surface of said reduction being rounded and placed in the extension of the outer surface of the tubular casing, said main body thus delimiting in the lower part of said assembly, a housing for receiving two pumps (17, 22) and portions of ducts, each pump (17, 22) being connected on the one hand to a portion of duct connected to a separate rainwater supply network and on the other hand to a portion of duct for the transport of rain or drinking water selected.