Water began flowing into Tempe Town Lake this morning. Three of the four rubber bladders forming the downstream dam were replaced, and the temporary dam was erected in place of the fourth bladder. The temporary dam will be replaced with another rubber bladder in a few months.
Relatively cool weather brought in by the recent storm compelled me to ride my bike down to the lake and take a look.
Three of the new rubber dam bladders are in place. I would think it would be smart to move that expensive crane out of the river bed before filling the lake, just in case.
The temporary dam in place of the fourth bladder.
The temporary dam leaks near the bottom.
Water to fill the lake comes from this culvert. The newspaper claims the lake is being filled at a rate of 100 cubic feet per minute. The water is from the Salt River, transported to the lake via the canal system.
Since the dam rupture, the lake bottom at the upstream end turned into a marshy wetland area. Plenty of Great Blue Herons take advantage of this shallow water. Soon, this area will be flooded. I also noticed there is still flowing water, about 50 cubic feet per second, flowing in the river channel. I initially assumed this water originated as flow over the upstream dam as a result of water treatment plant discharge, or from recent storm runoff. As it turns out, no water was flowing over the top of the upstream dam, nor was flowing from any other culverts or Indian Bend Wash. I conclude the source of this flow is water flowing under the upstream dam through the river bed sediment, and re-emerging on the downstream side of the dam. Now I wonder how much water Town Lake loses by flowing under the downstream dam.
The empty lake provided an opportunity to repair the footings on the Rural Road bridge. Interestingly, not all the footings were repaired. It looks like they wanted to repair all the footings, but ran out of time.
I also stopped by Papago Park, and saw these community college students learning how to measure stream flow. Well, I assumed that is what they were doing – as it brought back memories of when I did the same thing. They aren’t really measuring a stream, they are measuring irrigation water that is discharged into the Papago Park lakes. Unfortunately, this is probably the best location for such a field trip within 60 miles Phoenix. It’s not perfect, but it sure beats learning from a video in the classroom.
The flow through the Papago Park runs from the canal, through a series of lakes, and eventually into the Phoenix Zoo.