DRAINAGE DISTRICT ASSESSMENTS. 55 
that it is almost impossible, if not entirely impossible, for anyone 
to determine for himself what these percentages should be for any 
given district. 
The third step in fixing the assessments by this method is the 
evaluation of the benefit derived because of extraordinary benefits, 
such as that due to a tile drain crossing a tract of land. The usual 
method of allowing for this benefit was found to be the assessment 
of a sum equal to the cost of laying a 6-inch drain in the same place. 
When used with this system this method is probably as good as 
any that could be used but it does not conform to the theory of 
benefits. There are similar methods of taking care of other extraor- 
dinary benefits. 
To make a just assessment it is necessary that this system be 
modified, in most districts, by the consideration of several importai r 
factors which appear to have been neglected in many districts. Pos- 
sibly the most important of these is what may be called the " effect 
of the improvement." Few drainage improvements are constructed 
large enough to take care of the greatest possible rainfalls. The 
resulting great floods do not affect all of the land in the district 
in the same way nor to the same degree. ; ' Swamp " lands are 
usually the worst sufferers, and in some cases this hazard has proven 
so great that the condition of the ''Swamp" lands is little belter 
than before the improvement was constructed. Some place in this 
system the probable effect of the improvement should be taken into 
consideration, for data are now generally available which enable 
engineers to predict how often and to what extent the capacity of 
the improvement will be exceeded. 
Similarly, the effectiveness of the outlet should be considered 
since it is not always that a perfect outlet can be obtained. The 
lands at the lower end of the district are usually the ones which 
suffer most from this cause. 
Possibly the greatest objection which can be lodged against this 
method of making assessments is that it is very complicated and 
cumbersome. The evaluation of proportionate benefits in per cents 
and percentages of per cents is very confusing to the ordinary mind. 
All of these quantities are so indefinite and the whole process so com- 
plicated that it is impossible for the commissioners, should they 
desire to make a change in any of these established percentages, to 
know what the effect of such a change will be until after all of the 
field work and computations have been completed. In order to do 
justice to all. the commissioners should know at all times just what 
they are doing — that is. they should know the effect in dollars and 
cents of any classifications they may make, since the assessment must 
stand upon its equity as shown by its amount in dollars and cents, 
and not in per cents. As a matter of fact, this system is so compli- 
cated that in the general case the board of assessors does not attempt 
to understand it. Investigations show that the general practice is 
for the board and the engineer to go upon the lands and classify 
them according to their need for drainage into the four classes. The 
engineer then takes this classification into his office and using the 
various percentages which are in such general use. after some days 
or weeks spent in figuring, he finally arrives at the assessments as 
they are reported to the court. That is to say. the complications i^f 
