2015-05-05 P & Z Packet - Laserfiche WebLink

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Mike Ericson From: Paul Palzer Sent: Monday, March 02, 2015 10:40 AM To: Mike Ericson Subject: Met Council Draft Plan Hi Mike— I briefly went through the Met Council Plan and several things jump off the page. First,White Bear Lake has a watershed recharge area that is only 3.2 times larger than the lake. This is the 12t1 smallest in the metro area of 114 lakes identified in the study, in the bottom 10%. Thus,White Bear Lake has an historical fluctuation of 6-9 foot elevation correlating to rainfall amounts within this small recharge area. In contrast, Peltier Lake's recharge area is 120.4 times larger. Bald Eagle Lake is 18.7. 1 understand that lakes also gain water from springs running into them and some lakes have few springs while others have many. To me it would be a simple calculation of the watershed area to the lake area with evaporation taken into the equation to determine how large the watershed needs to be to maintain a constant lake level for a normal year and then to plug in draughts&wet years to determine drawdowns levels and recharge quantities to label normal high and low water marks for a given lake. It would not be cost effective to micro manage Nature's natural course designed for each lake by trying to pump water into a lake. It seems a little due diligence on behave of a perspective buyer of a lake home to understand how lake levels may rise &fall based on this readily available information. This would give them an idea how the lake levels will fluctuate over many years. Nature has seasonal and cyclical weather patterns and thus lake levels follow these and may take years and even decades to return to certain levels. Look at Lake Superior. It has taken many years for it to rebound back from being down just 18". The Met Council should adopt a policy to try to maintain lake levels on those lakes that have a recharge watershed area greater than 5 to 1 and identify lakes below this as susceptible to fluctuations due to normal weather patterns. Met Council has suggested that certain lakes are tied directly to the aquifer. If this was true, one would expect that when an aquifer falls even a foot at 180 down in depth, this would create a 18.6 psi of suction from the lake. The opening draining the lake would increase dramatically in size in a matter of weeks, let alone years. We see this on every water main leak. One day is barely bubbling out of the ground and three days later it is boiling out of the ground.To the contrary,when the aquifer were to rise,the lake would creep outside of its high water mark and historical data should show this too if it is the case. To put in perspective, a study of those lakes with a recharge area of less than 3.5 could be compared over the last 50 years,along with rainfall amounts and lake levels for each month. Along with this study, another study determining how much of the rainfall within the watershed recharge area actually reaches the lake. This possible could show the effective recharge area to be less than the size of the lake,which I would guess is the case with White Bear Lake. Paul 1