City of Iowa City Flood Plan

This is a great link. It will forward you to the Iowa City Flood Plain Management page.

1)The page gives great information about how floods are handled in Iowa City, and it allows site guests see if they are in the Iowa River floodplain. The Iowa River floodplain flows from Coralville into Iowa City on the north end of town. It is the floodplain that flooded the University of Iowa in 1993 and 2008.

Iowa River floodplain map

In this map you can clearly see the way that the river flows and which areas are most in danger because of it. 

Map from Des Moines Register

The map above is the flood map of the 2008 flood. Can you see how the two maps line up?

• The map above shows that the Waterworks in the North would be unharmed if the flood was a 100 year or 500 year. However, what would happen if the flood was a 1000 year? A 1000 year flood hit Tennessee in 2010 and destroyed a vast amount of property. Given how our input has affected the environment there is no accurate way of calculating if the chances of 1000 year floods have increased. The link here will take you to a page explaining the Tennessee flood.

2)The page provides a Flood Hazard Flyer which talks about the different things that people need to know about flooding. One of the main things that the flyer explains is the danger of flash flooding .

• The three creeks that are the most dangerous in the area:

-Ralston Creek- Hickory Hill Park, Scott Park,Woodlawn Historic District, Highway 6

-Willow Creek- western Iowa City and Iowa Municipal Airport

-Snyder Creek- south soccer fields, agricultural lands, Interstate 80

• Heavy rains and a prolonged winter that causes soil to freeze can cause these creeks to flood at an alarming rate. People need to understand the dangers of a flash flood. A flash flood is a sudden, localized flood of great volume and short duration, typically caused by unusually heavy rain in a semiarid area. Flash floods can reach their peak volume in a matter of a few minutes and often carry large loads of mud and rock fragments.

3)Flood safety tips given by Iowa City. One of the most important things about floods protection is education. This means that the more you know the better off you will be in the long run. Floods very drastically so knowledge and quick reaction are very important. 

PERSONAL SAFETY

• Keep yourself and children away from creeks, ditches, culverts, and storm drains during heavy rains.  The water is moving quickly and carrying heavy debris that can cause injury.
• Don’t drive through a flooded area.  Two feet of water can float a car into the nearest body of water.
•  Don’t walk through flowing water.  One cubic foot of water weighs 62 pounds and will float many vehicles.  Six inches of moving water can knock you off your feet. In a flood emergency, turn off the electrical power at the service box and turn off the gas that services your furnace. 
•  Do not use candles, lanterns, or open flames if you small gas or if you’re not sure whether the gas has been turned off.
• If you return to a home that’s been flooded, look out for animals, especially snakes.
•  Don’t keep furniture, rugs, clothing, or other items that cannot be completely cleaned of the sewage, chemicals, mold, and other consequences of a flood. 
• Don’t donate flood-damaged items to anyone.
• Don’t use a gas-powered generator or charcoal fire indoors if you’ve been left without power.  Carbon monoxide can slowly deplete the oxygen in an enclosed area and lead to brain injury or death.

PROPERTY PROTECTION MEASURES

If you discover that your property is in a flood hazard area, there are measures you can use to minimize your risk of flood damage.  

• Exterior walls can be sealed with a concrete or asphalt-based coating.
• Doors can be fitted with waterproof gaskets.
•  Plexiglas and aluminum shields can be installed over windows.

(These techniques don’t work for flooding over two feet, and require consultation with a structural engineer).

•  Utilities like furnaces and air conditioners can be elevated on raised platforms or mounted so that they are at least one foot above the flood hazard elevation.
•  Structures can be elevated onto a crawlspace with openings to relieve hydrostatic pressure, so the first finished floor is at least one foot above the flood hazard elevation.