Lakes Near Laporte 89 



testimony of citizens as authentic. However, the data on Lily Lake 

 can be considered authentic so far as fluctuation is concerned. 



The decline of five feet in the level of this group of lakes has 

 greatly reduced its area. By estimate the present area is slightly more 

 than half the area when the lakes stood five feet higher. If we con- 

 sider that area to have been twice the present area it gives us a work- 

 ing basis to determine the actual loss of water in the ten years. The 

 area of the present lake surface is .828 square mile. The former area 

 if twice as large was 1.656 square miles. The average area for the ten 

 years has been 1.242 square miles, which is 34,624,972.8 square feet. 

 The volume on this average area to five feet deep is 173,124,846 cubic 

 feet, the water loss in ten years. Thus, the loss per year has been on 

 the average 17,312,485 cubic feet. This loss has been much more rapid 

 than in the preceding years according to the testimony of citizens and 

 according to the record kept at Lily Lake. While the consistent loss 

 since white settlement of this region can be explained by deforesta- 

 tion and systematic drainage of the land, the increased decline within 

 the last ten years is no doubt due to the installation of the sewage dis- 

 posal system in the city of Laporte. 



Apparent Relation of Lake Level to Ground Water Level Prior to 

 Installation of Sewage System. When white settlers came to this 

 region and for a long time thereafter Clear Lake drained eastward 

 through the present city of LaPorte. During that time Clear Lake 

 stood at a lower level than Pine Lake. This is shown by the levels of 

 the old shore lines. Even at that time, however, theie was underground 

 drainage from Pine Lake through the Valparaiso moraine to the springs 

 whose location is shown in figure 1. There is every indication that this 

 drainage existed because of the steep gradient shown in table 1. Some 

 idea of the drainage of the region north of these lakes and no doubt 

 of the lakes themselves may be gained from observations at Harding 

 Pond, Section 22. Considerable areas north of this pond are drained 

 into it by tile drainage, one an eighteen-inch tile. During heavy rains 

 this tile and others flow full into the pond and fill it up to a certain 

 level above which the lake does not rise. Neither is there indication of 

 water entering Pine Lake from this pond. The two are separated by 

 a divide over fifty feet above Pine Lake. The distance from the pond to 

 Pine Lake is about one-half mile and the difference in elevation 10 

 feet. Thus the gradient from Harding Pond to Pine Lake is 20 feet 

 per mile but the springs north of the moraine are 75 feet lower than 

 the pond and two and one-half miles away. Thus the gradient to the 

 springs is 30 feet per mile. 



The peculiar topography of this moraine with its abrupt noi-thern 

 slope leaves the whole southern slope perched so high above it that the 

 tendency of the ground water below lake level is to pass beneath the 

 moraine and appear at the springs. There are no large springs on the 

 south side of the moraine. The material of the moraine is principally 

 gravel and sand while that of the Kankakee lowland is fine sand and 

 clay. There is every evidence that there is a deep seated underground 

 drainage even from the Kankakee valley itself toward Lake Michigan. 



