Lakes Near Laporte 93 



fell in the city as rain entered the soil and became ground water. Thus, 

 the water table was held up. After the installation of the sewage sys- 

 tem the storm water was drained directly from the streets into the 

 sewers. As a result there was a loss of water to the water table and 

 it declined. Mr. J. W. Good, well driller of LaPorte, stated that he 

 *inds the water table about seven feet lower now than at the time of 

 che installation of the sewer system. He states that the water table is 

 now from twenty-eight to thirty feet beneath the surface of the city. 

 The city bench mark on the court house lawn is at 812.32 feet eleva- 

 tion. Therefore the water table, according to Mr. Good, is at 782.32 

 to 784.82 feet elevation. If we consider the present water table as 

 being at 783.32 feet elevation in the business section of LaPorte, seven 

 feet lower than in 1913, and Clear Lake at 791.76 feet elevation or five 

 and one-hall feet lower than in 1913, we have the following comparison 



of levels : 



Clear Lake Level Water Table Level Difference 



1913 797 . 26 feet 790 . 32 feet 6 . 94 feet 



1922 791.76 feet 783.32 feet 8.44 feet 



If we now consider the business section of LaPorte as one-half mile 

 from Clear Lake, we find that the fall of 6.94 feet in the half mile is 

 practically the same as the fall of 13.3 feet per mile toward the city 

 wells (see page 88). By the installation of the sewage system the 

 water table was lowered about Clear Lake, thus steepening the water 

 table slope. This slope is still steeper than it was before the instal- 

 lation of the sewage system, so it may be that Clear Lake will decline 

 further. Since the supply of water to the lakes was not increased 

 when the sewage system was installed and the water table lowered on 

 this side of the lake it serves the same purpose as removing a retain- 

 ing wall from the side of a pond except that the response is slower 

 due to the very slow movement of the ground water. 



PropoHed Plans for Restoring Lake Levels. On page 89 the aver- 

 age loss of water per year from the lake system for the last ten years 

 is given as 17,312,485 cubic feet. Any means of restoring the lakes 

 to their former level must therefore furnish at least this much water. 

 Two plans are suggested. The first is to reverse the storm sewage of 

 the city into Clear Lake. All of the system north of and including the 

 Fifth Street sewer could be reversed. The area drained by this part 

 of the system is about two square miles and the annual rainfall on this 

 area slightly more than thirty-six inches. If we consider that the 

 sewers carry away one-tenth of the water which falls within the area 

 drained by them the amount disposed of during the year would be 

 16,727,040 cubic feet or almost enough to supply the deficiency. Since 

 it is highly probable that much more than one-tenth of the rainfall is 

 disposed of by the sewers and since the average loss per year to the 

 lakes is probably considerably over-estimated, this reversal of drainage 

 would probably be sufficient to prevent a further decline of lake level 

 and also tend to raise the level. 



A second plan is to drain areas of the morainic area north of the 

 lakes into them. As previously pointed out, there is now little of this 

 area draining into the lakes. However, between the lakes and the crest 



