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LAKE ELMO CITY COUNCIL MEETING, OCTOI3rR 219 1980 ..9_
<br />Mayor Armstrong noted that Alternative 1, construction of a flood protection dike,
<br />.is going to be done by Cimarron.
<br />Steven Taylor confirmed their construction of Alternative 1, then stated, I look
<br />upon -the raise of Sunfish Lake encroaching on our property and. any
<br />damage to our property as our problem. We are not expecting public money
<br />to pay for raising the dike or any damage to our property. It seems
<br />the other side of the coin is that if a public body of water rises
<br />predictably, and becomes at -health hazard, and there is nothing .further we
<br />can do about it, then, this becomes a public problem.
<br />Mayor Armstrong asked how .high the dike will be in alternative 1.
<br />Tom Noyes, Cimarron Ihgineer, stated basically, we are constructing alternative 1
<br />as listed, but slightly lower. The would provide for a lake level increase
<br />of 5 feet with. I foot of free—boexd or less than a 25% chance of flooding
<br />due to snowmelt.
<br />Armstrong said, if we out tho chance of .flooding from 100% to 2594 what do we have
<br />to do to eliminate the 25%. Is it enough to pump 67 1/2 acre feet of
<br />water from one side of the road to the other?
<br />Councilman Mottaz asked about Tom Noyes? statment that the treatment plant could
<br />not stand the pressure if th.e dike is built to the height proposed..
<br />Tom Noyes stated, if we have a lot of pressure greater than 3 ft. differential, we
<br />fear structural damage. We have placed piezometers on both sides of the
<br />treatment tank in order to monitor this. So, if we start to approach
<br />situation, we will have to take some other type of action. But, we see
<br />no other choice for Cimarron but to build the protection dike. This
<br />is 9,13. we can do.
<br />Armstrong asked if the dike is going to be as high as propoed in Alternate 1,
<br />Tom Noyes indicated they have not looked at any elevations. We have basically said
<br />that we are going to build a dike. We haven't drawn up plans as ,yet. It
<br />will probable be the same elevation.
<br />Armstrong said, if we assume that Alternate 1 is accomplished, and we reduce our
<br />chance of a flood —out to 25%; how much pumping do we have to do to reduce
<br />it , as close as possible, to a 0% chance.
<br />Larry Bohrer said, the lake level would have to be reduce two to three feet.
<br />Armstrong asked if pumping from the south to the north could accomplish this. The
<br />Engineer said. yes.
<br />Steven Taylor noted that if ,you effectively make a dike out of County 709 now ,you
<br />do not have a 22A lake in which to receive the run—off; now ,you have an
<br />B acre lake.
<br />Larry Bohrer said that if the run—off accumulates on the north side, we still have -to
<br />provide a culvert about 3 feet below the low point in the .road so that; I
<br />County Road 70 does not wash out. This is not a good alternative. It is
<br />just one of the alternatives. This is not the total answer.
<br />Armstrong read and reviewed Alternative 31 Gravity outlet -to horseshoe Lake, from
<br />the Engineer's Report. Ile asked, if this were put in place with a control
<br />valv4 at that point, would we have 100'/ assurance. This would allow us
<br />to pull the plug with everyones approval. and keep the water level down.
<br />Larry Bohrer said there may still be times when a fast run—off will make the lake
<br />rise.
<br />Tom. Noyes said, we do recognize, however, that the second effluent is almost
<br />1.00'1 certain to be topped, and that will in itself lower the wetter
<br />quality of Sunfish. If we can prevent that; then; any -transfer of water
<br />from Sunfish to Horseshoe would be easier, because the water quality will
<br />not be as degraded.
<br />Armstrong said, with your, dike in place, with Alternate 3 in place and operating
<br />before any snowmelt, that would sufficiently reduce it so that there would.
<br />be no danger of pollution?
<br />Tom Noyes replied, No, it would be past the % .figure of protection, but we still have
<br />the absorption pond that; has nutrients from the treated effluent that has
<br />a, very good possibility of being mixed with Sunfish Lake.
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