While this would create a short-term disaster, the diluted saltwater should mean good news later. With the spillway closed, freshwater cannot flow into the marshes east of the Mississippi River as it did before levees were built in the 1930s. Instead, brackish areas where oysters and young fish grow become too salty. The added freshwater should restore the natural balance. The spillway has been opened just eight times in its 66 years.
Bays control the amount of water that passes.
As of March 27, the Corps had opened 298 bays at a rate of 15 to 40 a day, Addison said. The spillway will probably stay open for a month, Addison said. By staying open, it is reducing the Mississippi River flood crest, currently at 16.8 feet, by a foot and a half to two feet. It is impossible now to predict what affect the open spillway will have on oyster production, Veal said. The Sound also receives freshwater from the Pearl, Biloxi, Wolf and other rivers.