10:16 AM
Flow analysis today. 3 sites. Each site is chosen because there is a sensor on the bridge constantly measuring the depth of the stream, courtesy of the iowa flood center. We get in to measure the flow ourselves so we can convert the depth measurement into flow.
First stop: ICThomas
Kaycee and I got into the stream. Kaycee waded the measuring tape across the stream. I held the other end in place for her. It was tricky because the measuring tape would keep lowering into the water and the current would take it under the water and down the stream. This process took a good 10 minutes.
The stream was about 53 ft. across so we measured flow every 4 feet for accurate measurements. I measured the depth of the water with a recycled yard stick and kaycee measured the avg. speed of the stream using the flow meter. These measurements are entered into a derivative equation and the flow is calculated.(Area (ft. x ft = ft2) x velocity (ft/sec) = flow (ft3/sec)). As we got further into the water the current got harder and faster. At 20 ft. the flow meter stopped measuring, the only reading we could get was 0.0 avg. speed. Kelsey called professor St. Clair and she went back to the lab to get a different flow meter. Kaycee and I filled the chloroform bottle to be used for lab standards and in the mean time decided to wade in the water. We entertained ourselves by doing water aerobics against the current. A few families on the bike path stop by and said hello, they asked us what we were doing. We told them we were measuring the water flow of the stream and all of the kids said, “oooooooo!” It was such a rush to know that other people were excited by what we were doing.
20 minutes later, Kelsey appeared with a huge blue flow meter. This worked and allowed us to finish measuring the flow of the stream. We got out and Kaycee and I removed our waders to find that mine had leaked. I knew I felt the flow of the current but I didn’t realize that the waders had filled with actual water. I was soaked to the top of my navel.
Stopped at McDonald’s to have lunch...got our mint chicken!
Continued to County Home Rd. while I dried off in the back of the car.
Second stop: County Home Rd.
Kaycee and Kelsey got into the stream. We discarded of the leaking waders in the back of the car and put them in a plastic bag. Kaycee wore the good waders and Kelsey got in with her water shoes. This stream had numerous sink holes composed of both mud and sand. It was a challenge to truck through all of the mud but they both were able to do it. Except Kelsey had a bit of trouble with the new flow meter at the beginning, it eventually started working and they continued down the rest of the stream. Meanwhile, I was above them recording the data and avoiding the being thrown over the bridge by the massive semi trucks, it felt like all of them were moving at magnum speed.
We left the stream and set off for the last site.
Third stop: ICS
Kelsey and I got into the stream and Kaycee recorded the data. Kelsey once again got in using her water shoes and I wore the good waders. We decided to measure from right under the sensor on the bridge, normally we measure a few feet in front of the sensor. Kelsey led the way in and ended up walking on rocks for a while until finding a steep drop off. She ended up with water past her collar bone. The water was very turbid though and we could not see the depths or rocks. I then followed her and set the tape measure in place on one side while she guided the tape to the other side. We began taking our measurements, since the creek was 45 feet across we measured at every 4 feet. At the third measurement the flow meter stopped working. Kelsey and I tried resetting it time and again but it was not measuring any part of the current. Suddenly the current had come and Kelsey had been swept away. Only her head was above water. She began swimming towards us, against the current but she only got tired. Eventually Kelsey found some shallow ground in the stream and we got out of the stream successfully. Both of us were soaked. It was a fun drive home.
