A toy water gun apparatus includes a gun housing having a water chamber and a pressurized air chamber in fluid communication with the water chamber. The water chamber preferably includes an expandable bladder for filling with a quantity of water and has a first end and a second end, the first end connected to a water inlet for releasable connection to source of pressurized water such as a municipal water supply, and the second end connected to a nozzle 10 valve. A trigger mechanism is connected to the nozzle valve to selectively open the valve to dispense a stream of water during play. The apparatus utilizes the naturally high pressure of a common faucet tap while the eliminating the necessity of constant pumping in order to maintain a desirable water stream. Pressure in the air chamber is never lost because it is entirely separate from the water-delivery mechanism.
