100-year rains may overwhelm drain systems
Hurricane Frances is about to give Central Florida the kind of drenching that comes around only once every 100 years or so, a deluge that will likely produce widespread flooding in the region.
Local officials say there is no way to prepare for the amount of rain -- 10 to 20 inches in about a day -- that parts of the region could receive this weekend. Even the newest, best-designed stormwater systems aren't ready, they say. And even if they were, debris from Hurricane Charley has clogged many drainage ditches.
The result: Neighborhoods that have never seen flooded streets could find themselves under water by Saturday evening as the massive storm moves slowly through the region.
"We're kind of looking at a record event," said Dennis Decker, warning coordination meteorologist for the National Weather Service in Melbourne.
"There are areas that are going to flood with this that will take people by surprise. And we can't tell you where those areas are going to be."
In Orange County, officials are looking nervously at the Four Corners area -- where Orange, Osceola, Polk and Lake counties come together -- and the rural eastern sections of the county, which slope down to the St. Johns River. Both are fast-growing areas, where pasture and groves are being turned into subdivisions.
In Osceola and Polk, where the broad, flat topography means heavy rainfall tends to pool rather than run off, officials are concerned about subdivisions like Poinciana and new growth south of Four Corners.
But older areas are also threatened -- such as downtown Sanford in Seminole County and Deltona in Volusia County.
Frances will pose a major test for the region's flood-control system, as well as for the drainage systems and retention ponds in the hundreds of subdivisions -- encompassing thousands of homes -- that have been built in the past few decades.
Some of Central Florida's decisions to allow home construction in wetlands and low-lying areas could come back to haunt it this weekend, said environmentalist Pat Harden, a former member of the St. Johns River Water Management District Board.
"Probably a lot of those places we thought they shouldn't have built, we'll find out if they should have built them," she said, alluding specifically to new subdivisions around the Econ and Wekiva rivers in eastern Orange and Seminole counties.
William Carlie, a permitting official with the water district, said that new subdivisions are engineered to handle 7 inches of rain in a 24-hour period -- the kind of storm that hits once every 25 years.
A "1-in-100-year storm" would deliver 10 inches of rain in a 24-hour period. Frances, which is projected to spend a full day over Central Florida, could double that amount of rain in some places, forecasters say.
"There's really not that much these [stormwater] systems will do for you with that kind of storm," Carlie said. "There's nothing I'm aware of that is designed for that."
Those most likely to see waters rise are people whose homes or apartments are near ponds, lakes, creeks, waterways and wetlands, said Decker, the weather service meteorologist.
In addition, anyone near the St. Johns River or its tributaries should expect water to rise for days after Frances passes, as the rainfall that drains into the waterway backs up because the system is full. Some of the most vulnerable areas are those near the river."Unfortunately there are people who have no idea it's possible for their area to flood, and it's going to flood," Decker said. "It's going to cause major problems."
City officials across the region were preparing for the worst. In Oviedo in Seminole County, the city brought in pumps to divert water near the downtown area. Other flood-prone spots include Alafaya Woods and Mead Manor, where runoff from newer development has exacerbated drainage problems, Mayor Tom Walters said.
"We know there's going to be high water in a lot of places," City Manager Jerry Seeber said. "Nobody's system anywhere is designed to handle 10 inches in quick order, and that's what we've been told to expect. Whether there's going to be actual property damage or not is going to be hard to predict."
On Thursday, some counties told residents in low-lying areas to begin evacuating. Seminole County ordered about 7,000 residents out of flood-prone areas, alerting them by using the county's emergency 911 system. Osceola County issued a voluntary evacuation order for low-lying areas, while Orange County said it would make a decision about evacuations this morning.
Most residents should know if they're in a low-lying area based on whether they've experienced flooding problems after big thunderstorms, said Alan Oyler, Orlando's deputy public-works director.
"I think most folks -- unless they've moved in in the last week -- have a pretty good idea that they've got flooding problems," Oyler said.
But some neighborhoods that normally don't flood could have problems because their street drains are clogged with debris left over from Hurricane Charley, Oyler said.
Older neighborhoods that were built before today's engineering standards are also at risk. Some of those communities, such as Deltona in Volusia County, have had chronic flooding problems in recent years.
Residents did what they could to prepare.
Deltona newcomer Jose Martinez, who moved to the south Volusia city three weeks ago from New York, filled sandbags to protect his Bavon Drive home.
"I'm sure this time there will be flooding," Martinez, 27, said as he packed his 11th bag in 20 minutes.
Luis and Jennifer Gonzalez, who live three miles from the St. Johns River in Sanford, said they were concerned about their back yard flooding but could not find sandbags in their area.
They stumbled onto a Deltona sandbag site during a visit to Luis Gonzalez' mother's house to get a generator and quickly doubled back to get a shovel.
"It'll give us a little peace of mind," Jennifer Gonzalez said.