Jim Brown: Flooding is a continual problem for the region

</element><element id="paragraph-1" type="body"><![CDATA[A torrential rainfall that dumped at least 11 1./2 inches of rainfall on Saline County March 18 and 19 , 2008 left millions of dollars in damage and property loss in its wake and left dozens of buildings shuttered after the rain subsided.

In Saline County, a preliminary estimate indicated $16.8 million damage in Harrisburg alone. Countywide, at least nine homes were considered destroyed and at least 30 homes and 44 businesses had water over the first floor.

Numerous businesses lost inventory and were closed for days while flood waters surrounded their buildings.

"It's probably the largest rainfall event that we've had since the watershed was developed," Harrisburg city Engineer Jim Brown said.

While the city is well prepared for normal rain events, the rain event in March 2008 wasn't normal -- almost any pump station would be overwhelmed. Water has to go somewhere.

"When you get up into that 100-year event, very few things are designed to deal with that," Brown said.

Meteorologists don't know how much rain can really fall over a period of a few days, or how often the perfect storm can come together to overwhelm any system put in place. Preparation and flood abatement programs are beneficial, but Harrisburg cannot completely eliminate the possibility of flooding.

"You must understand: We talk about rain events, 100-year events, but we only have about 200 years of data. So we are constantly revising a 100-year rain," Brown said.

The city of Harrisburg has two upstream impoundments that slow the runoff down, Brown said.

But when the river is high, as it was in 2008, the water is harder to pump out and the impoundments fill quicker.

The March 2008 floods were caused by headwaters from the 11 1/2 rainfall. The legendary 1937 flood -- which the city levee system is designed to mitigate -- was caused by the Ohio River overflowing and creating a backflow that made it all the way to Harrisburg.

Continuing problem

Flooding in Harrisburg and Saline County have been problems since the area was settled.

Brown and his firm, Brown and Roberts, have been the engineering firm for the city of Harrisburg over 30 years. Brown has numerous photos and written details of floods during his tenure. He recalled floods in 1982 and 1983 that were severe enough to cause property damage.

"None of this is new stuff," Brown said.

In January 1982 there was not as much rainfall as 2008, but the ground was frozen, which made drainage difficult.

In May 1983 an eight-inch rain inundated Harrisburg. Water rose around Kentucky Fried Chicken and King Liquors on Commercial Street and around Kroger and Wal-Mart -- similar to the flood of 2008, but with less damage.

Development has taken place in flood-prone areas. At one time, flood water was allowed to pool where the Arrowhead Point Shopping Center stands now, Brown said. One or two businesses or residences don't affect water flow much, but an entire business district makes a huge difference.

However, development follows the roads.

"This whole development is no one's fault. The highways were built in low-lying areas and development always follows the highway," Brown said.

Pankey Branch

The city has two drainage areas, Pankey Branch and West Harrisburg. The sewage treatment plant and the pumps are in the Pankey Branch watershed. The pumps can handle 36,000 gallons of water per minute, but a torrential downpour like the event of last March can overwhelm the big pumps.

Turning on the pumps as soon as rainfall reaches the point of a good downpour is not always a good idea, and can actually do harm.

"The pumps have to have five or six feet of submergence for an adequate feed of water," Brown said.

Brown compared it to starting an outboard boat motor on dry land -- a good way to burn out a pump motor.

Also, water flows into the Pankey Branch watershed from Ledford, past Harrisburg Middle School, along U.S. Route 45 and past the new Wal-Mart long before it reaches the pumps.

"And that's a pretty flat watershed. It takes a while for that water to get to the pumps," Brown said.

"The dynamics are pretty complex of this drainage system."

Post-flood steps

The city of Harrisburg is looking into several flood abatement and prevention steps, including an additional pump station, which the city council is considering funding using Tax-Increment Financing District money.

"One of the biggest areas affected was the TIF area around Terry Maynard's Appliance Store and the Kroger area," Brown said.

The city also adopted a comprehensive flood ordinance and joined the National Flood Insurance Program, which will allow residents to purchase flood insurance. Part of that process includes bringing in the Army Corps of Engineers to certify the levee, which takes time and careful study.

"That is probably a year process at best," Brown said.

The Army Corps of Engineers are going to look at the levee and the internal flooding when making a determination. The certification will also help determine where safe locations may be found inside the city portion of the flood plain.

The 2008 flood made people think about what could happen in the future and about how to minimize damage should the skies open again.

"I think one of the best things to come out of this is people are more aware of this problem," Brown said.

"We've made some major progress since the flooding."