NEW ORLEANS (AP) — A waterspout on Lake Pontchartrain headed toward land, and the lake rose enough to close one New Orleans floodgate.

The National Weather Service called a tornado warning for St. John the Baptist Parish and LaPlace because radar showed the waterspout moving landward Saturday afternoon.

After high tides, winds and heavy rains pushed the lake up to 2 1/2 feet, the U.S. Army Corps of Engineers closed the London Avenue Canal floodgate so the city could keep pumping storm runoff into the canal.

After Hurricane Katrina, the corps found it could safely hold 5 feet of water. The corps can pump 5,200 feet of water per second around the gate and into the lake.

Until Tuesday, the corps closed the floodgate only during tropical weather, if the lake was 4 feet high and rising.