CNN —Water levels are so low at Canyon Lake in Texas that an underwater cave and remnants of communities that stood more than a century ago at the site are reappearing. It was constructed in 1958 to help mitigate flooding and preserve water and was filled with water by 1968, according to the US Army Corps of Engineers. The drought combined with high heat to produce all-time low water levels. “I work on the lake, so I’ve been watching it drop,” he told CNN. As well the history that is coming to the surface.”A bridge and rubble from a previous house that was underwater at Canyon Lake in Texas reappeared due to historically low water levels.