More Iowa and the Floods

If you can't tell by now..... I love bike rides. I love to get out and see the country side. That is very easy to do in Iowa City. In about 10 minutes in any direction I can get out of the city. Here are some pictures from my ride yesterday.











One of my destinations was the damn.

At the damn I spoke with a park ranger from the army corps of engineers. She filled me in on some of the details. The water is flowing at a height of 4.5 feet over the top of the spill way. The spill way is 500 feet long. The flow rate of the entire dam is 38,000 cfs (cubic feet per second, for those of you who don't talk about flow rates everyday). The flow rate (Vdot) over the spill way is 16,000 cfs. Average water speed (v) = Vdot/xsec area of water above spill way!

v = 16,000/(4.5*500)
= 7.1111111 feet/s
= 4.85 mph

Doesn't seem very fast?...... that is the average speed over the top. Some parts will be faster then others. So........If we knew the change in height of the spill way we could see the increase in average speed from the loss of potential energy, not to mention how the cross-sectional area of the flowing water decreases by atleast a quarter after the drop. My guess is that the average water speed at its lowest potential on the spill way is about 25 mph. Something I do not want to get caught in! The water in this video is noisy. You can hear the rush!!!!!

To the immediate right of my helmet is one of the well heads that I sandbagged for two days. The picture was a little awkward, I used my head to block the sun (pun intended).



Once again, this is Burlington Bridge. They don't expect the flow rate out of the dam to decrease until Friday. Lets hope that we don't get any more rain.