The San Juan islander. [volume] (Friday Harbor, Wash.) 1898-1914, 1912-01-12
HIGHWAY DRAINAGE.
(By e. F. Ayres. Highway Engineer,
Oregon Agricultural College,

(By e. F. Ayres, Highway Engineer
Oregon Agricultural College.)
Oregon Agricultural College. Cor
wallis. 1t has been said that one O
the saddest sights IN Nature is At
forded by the man who gets stalled
lin a mudhole with his load Of pro
duce, and wears out his whip, his
temper, his vocabulary, his religion
and his team in q vain attempts t.
get to market. And yet this same
gentleman will probably oppose any
suggestion that the road should be
improved on the plea that the cost
would /be excessive. Overzealous
friends of the Good Roads move
ment are largely responsible for the
| idea that no road can be called i'm
proved without the use Of some ex
pensive surfacing, and this concep
| ton must be corrected before Ore
gon will fix her earth roads sufh
GENTLY to sustain the traffic. AS long
as this doctrine is confined to those
who openly oppose any attempt to
better our primary transportation
system, very little harm is done, but
when it is found to be the accepted
| faith of many road supervisors, II
assumes serious proportions.
In the construction of the most ex.
pensive pavement, not one ounce OF
road metal can be spread until proper
drainage has been provided, or In
other words, until first class earth
road has been built to sustain the
surfacing. If this work Is essential
a few days before the stone Is ap-
piled, why not try it few years
ahead and save time and money when
the increased traffic warrants the
larger expenditure Many of our coun-
try roads will need no surfacing for
many years if they are given little
attention now.
There are three rules which must
be remembered in the building OF
any road. from the mountain trail to
the city street LIST, get the water
off the road; End, get the water out
from under the road; Bird, get the
water away from the road If these
rules are followed you will have a
pretty fair road in any country, I'M
less you happen to be building
through a sandy country, in which
case all rules should be reversed.
To get the water of the road, it
lis simply necessary to keep the ruts
well filed, and provide sufficient
crown to carry the water to the side
bitches. In the heavier soils Of the
Willamette Valley a crown OF inch
to IL inches to the foot will be am
pie. On very wide roads this can be
cit oh h,rf 10 psoys n
cessary to build road over 30 feet
wide between ditch lines. On narrow
roads, such as are sometimes una
voidable in the mountains, the dis
lance from top of crown to bottom Of
ditch should be at least II inches.
The crown should not be increased
in this case, the extra depth being
furnished at the ditch line.
Everyone knows that the grade OF
Ia hill limits the load which can be
hauled over it, but few realize the
effect these excessive grades have on
maintenance and drainage. All grades
over per cent should be reduced
If possible, for on sleeper slopes the
water will be very apt to cut It's
own channel in the center OF the
travelled way instead of going to
the bitches. II the crown is increased
to point where the water will shed
quickly, the road is dangerous for
traffic. The road will not rut badly,
but the top layer OF earth will be
very slippery, and a large crown will
be likely to slide wagons into the
ditch. The old road builders took
care of the problem by building
thank-you-marms, or water breaks,
and while these had their use at
one time, they should no longer be
tolerated in a civilized community.
If the same energy expended in the
construction OF these denominations
is used in reducing grades and crown
ing the road. there will be no further
use for their existence.
Not only must the steep grade be
avoided In highway construction, but
care must be taken that the road is
not too level. Water must have a
slope of at least 4 inches in 100 feet
to flow freely in the bitches, and
no road should be built with less
grade, but in such cases the ditch
must be given the minimum slope,
and the water taken away at fre-
quent intervals. The better plan is
to raise the road above the surround
ing country anu Luou DdllQ 10 tQe
minimum grade in even fluctuations
OF about 500 feet.
1t Is a comparatively easy matter
to get the water OF the road, the
real trouble beginning when we try
to get the water out from under the
road. In this respect the road builder
in sandy country has the advant-
age, for he Is never troubled with
either springs or seepage. The heav-
Ter soils will develop soft spots and
holes which seem to be bottomless.
even after the surface has been thor
oughly drained. The road drag fails
to remedy conditions, and all gravel.
stone, brush or other material dump
ed in the holes is soon lost.
It ID very probable that this DIM
Guilty is caused by the underground
spring, and the frst problem is to
locate its source, remembering that
this IL rarely found at the spot where
the trouble develops. When Il has
been found, excavate trench about
inches wide and three feet deep to
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