Giant Springs Trout Hatchery is a production facility constructed in 1928. Reconstruction took place in 1984 when all the old round ponds were replaced by 24 outside raceways, except for one, which is now the show pond. The hatchery building was replaced and houses the egg incubators and 40 interior raceways, which can be seen from the visitor center. Giant Springs, the hatchery's water supply, is one of the largest springs in the country, and is the headwaters of one of the world's shortest rivers, the Roe River. The springs put forth over 150 million gallons of water each day, flowing into the Roe River which is only 201' in length. Water to the hatchery building is 650-700 gallons per minute. The outside 24 raceways receive 15,000 gallons of water per minute. The water is high in nitrogen and low in oxygen because it is from a very deep aquifer. As a result, the water from the spring is pumped through packed columns to reverse this condition and provide better quality water for fish rearing.