Lake Dunlap suffered a catastrophic spill gate failure on the dam in May 2019, leaving the lake drained to only the riverbed. Plans are underway to repair the failed spill gate but a date for refilling the lake has not been made public at this time. Additional Lake Dunlap News. Located on the northwest border of Guadalupe County near New Braunfels, within an hour’s drive of both Austin and San Antonio; this 410-acre lake has a storage capacity of 5,900 acre-feet. Maximum depth near the dam is 40 feet.