A water supply control system for use with a fire hydrant comprises a four-way valve assembly having a first inlet port for coupling to a nozzle of the fire hydrant via a fire hose, the four-way valve assembly operable to selectively open and close the inlet and outlet ports according to an operating mode of the four-way valve assembly, a stable and sturdy platform substantially supporting the weight of the four-way valve assembly, a flexible tether strap secured to the platform at a first end and having a fastener at a second end for releasably coupling to the fire hydrant, a status indicator mounted on the four-way valve assembly operable to provide a visual indication of the operation mode of the four-way valve assembly, and a scene light mounted on the four-way assembly operable to provide high-intensity illumination.