i.raixa<;k district assessments. 19 
fits resulting in the porous soil would greatly exceed those derived 
on the second tract, providing the lands were otherwise equally valu- 
able; but, as each tract must be given credit for all of its natural 
advantages, such a conclusion is not correct. The porosity of the soil 
is one of those properties which go with the land. Where an extraor- 
dinary lump-sum assessment is placed on lands crossed by tile drains 
on account of direct drainage the assessment should be the same per 
linear foot for all kinds of soil, and this amount should be determined 
by the benefit received by the most impervious soil in the district. 
A factor called " condition of the land " is sometimes correctly used 
in estimating benefits. If land is in timber the full benefit of drain- 
age can not be secured until after the timber has been cut, the stumps 
removed, and the land put in shape for cultivation. This work may 
require four or five years for completion. In other cases lands are 
so gullied and washed that considerable time and labor are required 
before full benefit from the drainage improvement can be secured. 
Where the benefits are determined as being the increased value of the 
land, this factor affects both the drained and undrained values so it 
has no effect upon the amount of benefit. Where the assessments are 
determined by other methods it is only just to make allowances for 
the time lost as other more fortunate lands will begin to receive bene- 
fits as soon as the drainage is under way. Care must be exercised that 
this allowance is not so large as to penalize the landowner who by 
a larger original investment or by improving his own lands has them 
in shape to secure immediate returns. 
The distance of the tract from the district outlet should be consid- 
ered when the land is so situated that it is possible to secure an inde- 
pendent outlet for its drainage. Such a case is exceptional, and, when 
it is found, the assessment should be no larger than the cost to the 
owner of utilizing the independent outlet. The theory that the bene- 
fit increases with the distance of the land from the district outlet can 
be applied only in States following the common-enemy rule for sur- 
face waters, as it does not apply in States which follow the civil-law 
rule. 
Another factor which is sometimes considered is the situation of the 
land with reference to roads, railroad stations, markets, and cities; 
but since the property owner has paid for advantages of location this 
factor should be entirely omitted. 
Application of special benefits to irrigated distHcts. — -Precipitation 
is generally very light, often negligible from the drainage stand- 
point, in districts where irrigation is practiced. Problems concerning 
overflow are almost never encountered in irrigated drainage districts. 
Drainage design has little to do with surface water. These facts 
serve to indicate that the situation is somewhat different from that 
in eastern districts where such factors are of prime importance. 
It does not follow, however, that the basic principles relating to 
assessments fail to apply. 
The artificial application of water to land in irrigation gives rise 
to unusual conditions as regards drainage. Lands thai naturally 
never have been moistened beyond the first few feet in depth are sup- 
plied with such copious quantities of irrigation water that not only 
is the soil thoroughly saturated but percolation beyond the root zone 
takes place, resulting eventually in a rise of the ground-water table 
in many cases nearly or quite to the surface. 
