The familiar scramble is under way to prepare for floodwaters that are headed to the Quad-Cities.

The predicted Saturday crest of 19.6 feet on the Mississippi River put area public works crews to work Wednesday in the most vulnerable areas, including Davenport's River Drive. Flood stage at Lock and Dam 15 in the Quad-Cities is 15 feet, and city officials are preparing for possible increases in the crest, given the unpredictable nature of new rainfall.

A section of East River Drive, from Brady Street to 3rd Street, will be closed today. The Hesco barrier system that has proven its effectiveness in recent floods will be used to protect River Drive and Credit Island Lodge.

Sandbagging volunteers are not yet being called up, Davenport officials said, because the barrier system is so effective. Sandbags were placed around the bandshell at LeClaire Park by city crews, however, and the portable floodwall was taken out of storage Wednesday to protect portions of Modern Woodmen Park.

The Credit Island causeway is closed to traffic. Pumps are in place in Davenport's Garden Addition and, in Moline, portions of North Shore Drive along the Rock River are closed.

Davenport Public Works Director Mike Clarke said the river-level models that are being used to forecast the crest are "credible," but they do not take into account new rainfall after today. Additional precipitation locally and in the three river basins north of the Quad-Cities could have an unforeseen impact on the crest, he said.

"The Turkey River is in play right now," he said Wednesday afternoon. "Then there's the Maquoketa River and then the Wapsi. As they drain, we see the impact."

To be safe, he said, the Hesco barriers were being set at 21 feet in most areas and at 22 feet around the lodge at Credit Island. High winds along the Mississippi River at Credit Island can cause "waves" against the flood-protection system, which can produce a risk of a breach.

"Also, I don't get a second chance to get it right at Credit Island," Clarke said. "Once the water comes up, we can't go back. The only way to get in is with a fire boat."

Heavy rains also are creating cause for concern along area creeks, including Duck Creek in Davenport and Bettendorf.

"The DNR is looking at all our previously known problem areas," Clarke said. "As of noon (Wednesday), we didn't have Duck Creek up and out of its banks. We are prepared to knock on doors tomorrow (Thursday) if flash flooding is imminent. We can help, possibly, with evacuation. Duck Creek is a wild card. We also can use our robo-calling system to notify residents if they are in jeopardy and need to make preparations."

Residents along the Rock River in Moline and Rock Island also are being warned to be on standby in case there is a need to evacuate.

Rock Island County Board Chairman Phil Banaszek issued an alert Wednesday afternoon, saying, "Please be advised that the Rock River is expected to crest at near-record levels and the Mississippi is also on the rise. Due to the great deal of rain received today, the river is rising very quickly. Caution is encouraged. Motorists are asked to be alert and not cross flooded roadways. When preparing to relocate, please make sure that medications are packed and that animals are taken care of."

Among the handful of businesses along the Rock River in Moline is Len Brown's North Shore Inn, which is one of the first locations to be affected by floodwater. By 1 p.m. Wednesday, water had reached the downriver parking lot at the tavern. Upriver, on the east side, flooding can make access to the tavern difficult.

"We put the planks out for people to use when the other lot floods," manager Sandy Lawrence said.

Upon hearing the news of the predicted crest on the Rock, Lawrence replied, "Holy cow! I'm glad I don't live down here anymore."