Monday, June 16, 2008

Flooding Peaks

More Flood Photos
In case you haven't seen some, I wanted to post what it was like in Iowa City this weekend. We still had a great time. (See Here), but it was sad to see what people are going through all over Eastern Iowa.
Got some aerial photos from the Press Citizen. This is the spillway and dam, normally just a trickle below the dam.

One of many historic things destroyed, sadly the Sutliff Bridge was one.

Houses down by city park.

Taco Bell, well I just wouldn't eat there in Coralville ever again no matter how much they clean.

The Coralville strip under water.

The picture above is water from the spillway, washing down where it has only been once before.

Here's an aerial photo of the spillway flow. Note, normally NO water is flowing right there.

Just North of Iowa City along 380.

1 comment:

Chadwell said...

So here's my explanation for the crazy CF stages:

Due to the fact that all stream channels change over time (get deeper, shallower, meander, etc), the USGS decided that measurements should be grounded on fixed point and elevation, called ‘Datums’. These fixed points are outside of the river channel and have been sited in by engineers at a specific height above sea level. So river stages are actually levels measured above that fixed point, not the true depth of water. In Cedar Falls’ case the Datum is 763.1’ above sea level, the gage is actually ~70’ above that, so measurements are quite a bit higher (floods would be ~863.4’ ASL). So the actual values are true river elevations, just like the lake stages. They just don't tell you the other part of the equation.

Most of the time the fixed point is quite a bit closer in elevation to the gage, and we get normal looking stages around 20-30’. But for some reason Cedar Falls datum is significantly lower than the gage height.