Facebook founder Mark Zuckerberg's already massive Hawaii estate has suddenly grown much more. According to the Honolulu Star-Advertiser, the internet millionaire and his wife, Priscilla Chan, recently purchased 110 acres of agricultural land on the island of Kauai, which contains the majority of a century-old reservoir originally utilised by a sugar plantation operator. The $17 million purchase follows Zuckerberg's $100 million purchase of 700 acres in Kauai in 2014 and his $53 million purchase of 600 neighbouring acres in April, according to the publication. The couple's Hawaii home is located on the combined 1,300-acre property. The couple's publicist, Ben LaBolt, told the Honolulu Star-Advertiser, "Mark and Priscilla continue to make their home at Ko‘olau Ranch." According to the newspaper, the 110-acre purchase comprises the majority of the Ka Loko Reservoir, which burst in 2006 and killed seven people downstream after discharging an estimated 400 million gallons of water. The reservoir is still on Hawaii's list of high-risk dams as of Monday, although it is restricted to a low water level by the state to reduce the chance of repeat tragedies. According to the Honolulu Star-Advertiser, it was built in 1890 and was originally utilised by sugar plantation operator C. Brewer & Co. According to the newspaper, a first 1,272-square-foot residence was built on Zuckerberg's Kauai acreage in 2017, according to property records from Kauai County. It was also revealed that he now has building permits for a 35,888-square-foot mansion on the property, valued at around $35 million.