Pella Chronicle

April 19, 2013

Rains wallop southeast Iowa

By CHELSEA DAVIS and MATT MILNER Courier staff writers
Ottumwa Courier

---- — OTTUMWA — Everyone knew it was coming. And when the rains hit southeast Iowa, they hit hard.

Lee Asher, manager of the Wapello Rural Water Association, said Wednesday night's rainfall washed away 90th Street east of Izaak Walton League, taking out water pipes and leaving customers without water. A water main break also occurred 1 mile south of Ottumwa, resulting in a water boil advisory for residents on River Road, Miller Chapel Road, Rabbit Run Road, 60th Street and the surrounding areas.

He said he didn't know how many customers were without water as of Thursday morning and wouldn't know until the leaks were isolated.

"Right now, we're still in the process of trying to find it," he said. "We've had people out since way early [Thursday] morning trying to find it in the dark, which is hard to do."

The washout will close the road for most of the summer, according to county officials.

Jean Dell lives on the side of 90th Street where the water pipe was carried away in the rush of water.

"We're at the end of the line going east, so people at the top of the hill on 90th Street still have water because they pump to them from the other direction," Dell said.

The Dells have been without water since around 5 a.m. Thursday, she said.

Ottumwa Water and Hydro general manager Mike Heffernan said he's unaware of any problems with water lines in city limits.

Water and Hydro production manager Tim Albert recognized early on in the storm that the large box sewer in front of the water plant was getting full.

"So he contacted the city sewer department, and they turned on some of the pumps at Blakes Branch," Heffernan said. "When that didn't help, we got big diesel pumps in the Market Street Bridge parking lot to pump out the sewer. And it's a good thing he did, because I heard later on [Wednesday] evening part of Gateway Drive had some minor flooding."

Flooding could have been much worse had the sewer not been pumped out, he said.

"We would have had some pretty serious problems on Gateway Drive," he said.

A new flood wall currently in the design stages will help make sure water doesn't back up into the water plant and flood the area.

A $16 million FEMA grant awarded to the city in August will go toward the West End Sewer Separation Project, as well as the installation of a flood wall around the water plant, construction of a storm water pump station and updated gate well structures in the existing levee that will convey overland storm water into the Des Moines River.

"We need to make sure it gets in the right place so it doesn't flood us out by keeping the water in," Heffernan said.

The city sewer department also worked in The Beach Ottumwa parking lot Thursday, pumping runoff from the oxbow lagoon so water from the south side had a place to drain.

City Public Works Director Larry Seals said thankfully John Deere Ottumwa Works donated the use of tractors to help secure the pumps from the oxbow lagoon to the river.

"We wouldn't have been able to keep up with the lagoon water without them," Seals said.

Pumps ran from the oxbow lagoon next to The Beach Ottumwa into the Des Moines River, as well as from the north-side interceptor into the river.

"Anytime you close the levee for a river flood, you close off the water behind the levee," he said. "The challenge becomes to get the interior water from the protected side into the river."

The oxbow lagoon acts as a retention basin, he said.

"This rain event was intense enough that it came up to 7 feet in the last 24-hour period," Seals said Thursday afternoon.

Crews were preparing for the storm all day Wednesday until around 2 to 3 a.m. Thursday, he said. Electrical crews worked on traffic signals, street crews worked on sandbagging certain intakes and setting up barricades on flooded streets and sewer crews maintained pumps all night long and set up generators.

Current forecasts indicate the crest of the Des Moines River at Ottumwa will take place Thursday or Friday, but that won't be the end to flooding.

The National Weather Service's advanced hydrologic prediction service shows a forecast for river levels. The crest is expected to be 16.6 feet, but that will depend heavily on how much rain falls in the next couple hours. Ottumwa's official flood stage is 11 feet, though the city's levee is designed to withstand river stages up to 25 feet.

River levels are expected to drop quickly, reaching a low of about 7 feet by 10 a.m. Saturday. But that's a rebound, not an end to the situation. Releases from upstream reservoirs will put the river back at 11 feet by late Monday.

The National Weather Service on Thursday revised its flood warning for Wapello County to eliminate an ending time. The warning will now be in effect “until further notice.”

According to the National Weather Service in Des Moines, Ottumwa far surpassed its daily maximum rainfall on Wednesday with 4.88 inches. The previous record — 1.56 inches — was set in 2008.