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The outcome of this wide-spread interference with the 
established condition of natural drainage has given ground for 
the almost universal testimony that streams which in former 
years held a continuous flow throughout the summer no longer 
run in the dry season. The reservoirs at their head waters are 
emptied and the supply of ground water is early exhausted by 
the artificial drainage in their basin. There is also a consider- 
able concurrence of opinion that,in the smaller streams at 
least, the floods come more suddenly and rise to greater heights 
than they did in former years. The “wash” along the banks 
and consequently the amount of silt carried in suspension by 
the flood waters are thus increased. 
The presence of under-drainage undoubtedly facilitates the 
discharge of such water as reaches the drains, but this impetus 
is in large part counteracted by the greatly increased power of 
absorption of the soil when thus drained. Heavy rains upon a 
soil already surcharged with moisture may lead to even a 
greater run-off than the same rainfall upon the same territory 
rendered porous and capable of absorbing and retaining, for a 
short time at least, a large amount of moisture. 
From many points of view the subject of the effect of drain- 
age of the catchment-basin upon the flow of streams is one of 
interest and importance. For its adequate discussion records 
of a long series of years of the stages of tributary streams and 
the river both before and after the installation of the drainage 
system are needed. With a view to throwing some light upon 
the possible effect of drainage upon the floods in the main river, 
and consequently upon the plankton, I have tabulated the 
fluctuations (in excess of .25 foot in 24 hours) in the river level 
at the lower gage at Copperas Creek for an earlier and a recent 
period, each of five years. The earliest authentic records which 
I have been able to secure begin with 1879. This antedates the 
completion of a considerable portion of the artificial drainage 
of the river basin. I have accordingly chosen the records of 
1879-1883 inclusive for comparison with those of 1592-1896 
inclusive. This choice is unfortunate in one respect, for the 
earlier series lies in a period of heavy rainfall and the later in- 
