The U.S. Army Corps of Engineers is going into serious drought mode in the Apalachicola-Chattahoochee-Flint River basin, which includes Lake Lanier.“The minimum flow into the Apalachicola River to protect threatened and endangered species becomes 5,000 cubic feet per second,” said E. Patrick Robbins, spokesman at the corps’ Mobile District.“We will maintain this minimum flow and store all available rainfall when possible until the basin recovers sufficiently to come out of drought operations.”The Apalachicola flows through the Florida Panhandle into the Gulf of Mexico.“The impact to Lanier is we can store any rainfall that now occurs,” Robbins said. “We don’t have to release additional water.”Stream flows “are reaching historic low levels throughout the basin and have already set record lows on the Flint River due to lack of normal winter and spring rains,” Robbins said.“These extreme low flows have driven the composite conservation storage in the federal reservoirs to the (level that) triggers drought operations.”Lake Lanier stood Tuesday at just above 1,065 feet above sea level, or 6 feet below the summer full pool of 1,071 feet, and is projected to hit 1,063.90 feet by May 31, or in time for the busy Memorial Day weekend and beginning of peak recreational activity. Despite spring rains in March at several areas throughout the ACF, overall conditions on the Flint and lower portions of the Chattahoochee have remained in a drought situation since the end of last summer, according to the corps.As the limited spring rains stopped, the inflow conditions throughout the basin have dropped.“At this time, the long-range forecast for the ACF basin does not look promising,” Robbins said.“It will take significant and frequent storm events to recharge the basin hydrology, or a tropical system, before operations and lake levels return to normal.”State Climatologist Bill Murphey has said the forecast calls for a gradual move toward “a slight, or weak, El Niño by the end of the summer ... (having) a bigger impact on tropical activity.”In agreeing with Robbins, Murphey added: “The way it looks now — since we aren’t getting abundant rainfall and good precipitation systems moving through the area — it’s probably going to take something like a tropical system to get us out of these (dry) conditions.”The last time Lake Lanier was at full pool was May 1, 2011, when the elevation began its downward slide.