Outside , and at a cost of Dh 800 million ( US$ 217 million ) , a record-setting fountain system was designed by WET Design of California They also built and planned out the fountains at the Bellagio Hotel Lake in Las Vegas . Outside , and at a cost of Dh 800 million ( US$ 217 million ) , a record setting fountain system was designed by WET Design , the California based company responsible for the fountains at the Bellagio Hotel Lake in Las Vegas .