His parents' house sits on Eagle Lake, which the Army Corps of Engineers expects to rise significantly.
"We could have 5 feet of water in there," Gelston said, nodding at the house. "That's what they're telling us."
A little more south in Rolling Fork, Miss., the birthplace of McKinley Morganfield (better known as Muddy Waters), tension was high.
"It's weird," said Lakeysha Stamps, a waitress at the Highway 61 Cafe. "Here we are today and everything's fine. And tomorrow there could be all this water!"
The sentiment was the same elsewhere.
In Memphis, Tenn., at a well-to-do enclave known as Mud Island, residents were getting too much of their beloved river. Rising waters practically lapped at the back porches of some of the island's expensive houses.
"I'm going to sleep thinking, 'I hope they don't evacuate the island and we wake up and we're the only ones here,'" said Emily Tabor, a first-year student at the University of Tennessee's College of Pharmacy in Memphis who lives on Mud Island.
The island pays homage to the mighty river with an elaborate scale model of it, a museum about its history and a paddlewheel steamboat that looks like something straight out of "Huckleberry Finn."
The three-mile-long strip of land that is part of Memphis has about 1,500 homes and businesses and 6,000 mostly well-off residents, many of them living in gleaming, 20-year-old houses with wide river views and traditional Southern touches such as columns, porches and bay windows. Tourists can take a tram or drive across a small bridge to visit Mud Island's park, amphitheater and a museum devoted to life on the Mississippi.
Emergency officials warned that residents may need to leave their homes as the river rises toward an expected crest Wednesday of 48 feet - about 3 feet higher than Thursday. The record in Memphis, 48.7 feet, was set in 1937.
Water pooled at the lowest end of Beale Street, the most famous thoroughfare in the history of the blues, but it was about a half-mile from the street's popular restaurants, shops and bars and did not threaten any homes or businesses.
In south Memphis, Maria Flores spent her fourth day in a church shelter with her husband and three children. They had to flee their trailer in the low-lying working-class Memphis suburb of Millington when it was swamped by stinky, dirty water. They have no flood insurance, and sleeping in a room with 20 other people, including crying children, has been difficult.
"We don't have money, we don't have anything," Flores said. "It's like a bad dream we can't wake up from. I just want this water to go away."
On Mud Island, meanwhile, the Mississippi engulfed a riverside park and bike path. At the private Maria Montessori School in the wealthy, 500-home Harbor Town section, several feet of light brown river water inundated the garden. Students and teachers built a sandbag wall to keep the water out of their classrooms.
"We've done our best to protect our building. This is very scary to me," principal Maria Cole said.
Russell Carter, who owns a pizza restaurant in Harbor Town, said he plans to stay with his wife and 9-month old daughter, mainly to protect his home and his business from the water and possible looters.
He said he is not too worried because he knows neighbors in the community he described as "Mayberry without Barney Fife" will be there to help if there's trouble. They are planning to hold a flood party Saturday.
"I've got too much invested," Carter said. "I'm not going to leave what I've worked for and what my family has worked for."
Elsewhere in the flood zone Thursday:
- In Kentucky, authorities closed 250 roads in 50 counties. The Coast Guard rescued at least 28 people, 12 cats, and three dogs from rising waters.
- In Missouri, the Army Corps of Engineers blew a third hole in a levee to relieve pressure and prevent catastrophic flooding there and in Illinois and Kentucky. The Mississippi continued to rise in Caruthersville, where a high-mark set in 1937 was surpassed on Wednesday, but was generally going down elsewhere in the state. The water was expected to crest Sunday in Caruthersville at 49.5 feet, just a half-foot below the top of the floodwall protecting the community of 6,700.
- In Louisiana, National Guardsmen used sandbags to fortify levees in the northeast part of the state, and the state penitentiary stood ready to evacuate prisoners. Officials were planning to open a spillway in the southern part of the state to divert river water.
- In Arkansas, truckers tried to rearrange their routes to avoid a 23-mile stretch of Interstate 40, a major link between the East and West coasts, where the rising White River forced the closing of the westbound lanes. Drivers were forced to take a 120-mile detour toward Little Rock.
By ADRIAN SAINZ