Dam Inspection with Dave Taylor
March 16, 2006 
Dave Taylor from Strata Services and Drilling Service Co. inspected the leak at the toe of the dam. 
He made these recommendations: 
1) Put in a weir below the leak where it has formed a creek. (A weir is a device placed across a stream to measure the flow rate of water.) Monitor it on a regular basis, measure the flow per minute and note if there are any changes in coloration or silt in flow. Silt in the outflow would indicate deterioration of the earthen dam, which would need immediate attention. 
2) In June as lake water warms, check the temperature of the lake at different depths with an electronic temperature gauge. Compare to the temperature of the water in the leak. This would tell us the depth of the leak in the lake, though not its location. 
Another alternative is to release dye at different depths and locations then check leak for coloration. For the dye test to work we would need to have a good idea where the leak was, since the dye would have to be released directly into the leak, If the dye is just released into the lake it would diffuse everywhere and come out the leak. This would tell us the leak was from the lake (which we already know) and give us no useful information on location or depth of the leak. 
3) Check our files for information regarding the concrete structure on the back of the dam that collects and channels the leak to the toe of the dam. If no information is available examine it and make a drawing.
4) Check our files for any information about the dam construction and the repair work done to fix earlier leaks in the dam. If the steel pipes (2 3/8”) could be found where the bitumen was used to fix the dam leaks before, it would be of great help, since it is very likely the leak we see today is due to failure of the earlier leak repair. Dave found a piece of bitumen in the water just beyond the pipe in the stream below the leak. Dave indicated that it was common practice to use bitumen (an asphalt-like material) to repair dam leaks, but the repair is not permanent. 

Dave felt the leak was near the concrete structure and in the area to the north, possibly in a small dolomite cave near where it was repaired before. 
The leak is of concern for two reasons: water conservation (retention) and dam safety. Dave guessed we were losing 200-300 gallons per minute. He also suggested we contact 
Bob Clay in the Dam Safety Office in Rolla, they will have a file on Lake Tishomingo. 
Dave could conduct a survey for $2,000 to find the source. It is our understanding that It would not tell us the location of the leak. 
Finding the pipe is useful because the leak is probably in the same location as the previous leak. 
If he was to repair the dam. it would cost $60,000 to $100,000, which would include an engineering survey of the dam and permits from the Dept. of Natural Resources. 
We will email Dave the inches lost in the lake level and he will calculate the approximate size of our leak in water flow per minute. 
He volunteered to come speak to L.T. residents, he is a former property owner. His phone numbers are: 
314-291-1111; 636-398-5858; cell 314-808-5858; FAX 314-291-1115. 
Email stratainc@mindspring.com 
Henry Brym, Rich Hirsch, Kevin Seelbach and Marilyn Meyer