Does City Need A Second Opinion

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According to City Hall Professionals:
Siphons Won't Handle Winter Flow
Are Not Practical
Really??

I have found it curious that the city hall official position is that you can not control the winter flow rates of the Chase River using siphons and/or pumps. This is the prime reason given for the opinion that the dams must be destroyed as the only way to address controlling winter water levels.This in spite of the fact it presents many issues that could be avoided if council simply adopted Councillor Pattjes motion rather than Counillor Brennans'.

I asked Mr. Sims about using siphons and he said they simply could not handle the winter flow rates. Mr. Kenning said professional engineers say it is not a practical method of control.

Really??

Not being the sort who simply takes someone's word for things, even if they are referred to as the professionals at city hall, I did some investigation into the matter, prompted by the fact a local company is willing to enter into a design-build contract which involves reducing the winter water levels as a means of addressing the immediate safety issues.

I came across an article in the Association of State Dam Safety Officials: Installation and "Operation of a Siphon System to Provide Water Supply Releases (2003)" which would seem to offer an opinion contrary to our own Mr. Sims or Mr. Kenning or Mr. Hickey or Mr. Cooper I presume.

The dam referenced in this study impounds 383 - million gallons and serves three purposes, flood control, recreation and water supply. Due to operational issues with the sluice gate,  they chose to design and install a siphon to transfer water from the lake to the receiving stream.

 Now, for some boring technical details, the siphon they installed was an 8 inch diameter siphon made of galvanized steel, it was 1,095 feet long and included a gate valve, butterfly valve and 3 ball valves for priming and discharge control. It took about 35 man-hours to complete. The siphon provided continuous flows of up to 1.6 mgd during the fall and winter months.

The operation of this siphon proved so successful, they installed a parallel 12 inch diameter siphon which provides flows of up to 2.9 mgd ***.

It seems that if our water technician is of the opinion  a siphon could not control the winter flows, I wonder if there are other opinions that need a closer look?

As for the city manager, he of course just relies on the opinion of the professionals, as construction and dam safety are certainly nothing he is expert in. An example would be his earlier opinion it would cost $30 million to replace both of the dams. 

So, the next time someone tells you a siphon couldn't control the winter flow rates you really have to ask them where they are getting their information. Of course one 8 inch siphon is not sufficient to deal with the winter flow, you have to increase the total diameter of the pipe/s to handle the calculated flow. The point is, it can be done.

*** mgd =  million gallons per day is a measurement of water flow frequently used in measurement of water consumption. One mgd equals 133,680.56 cubic feet per day, 1.5472 cubic feet per second or 3.0689 acre-feet per day.