Lake Dias is located in north-central Volusia County. The lake lies on the northern part of the Deland Ridge, near the eastern edge of the Central Lakes District which is the principle recharge area for the Floridan aquifer. The ridge straddles the swampy lowlands of Lake Woodruff to the west and Little Haw Creek to the east. The Crescent City-Deland Ridge physiographic subdivision consists of sand hills with summits generally between 24 and 30 m (79 and 98 ft) in elevation. Plio-Pleistocene sand and shell rest directly upon the Floridan aquifer. The lake level at the time (August, 1994) of the seismic survey was 10.6 m (35 ft) NGVD. Lake Dias is oval in shape, with a perimeter of 8.7 km, an area of 4.3 km², and average water depth of approximately 3 m (6 ft).