American Society of Civil Engineers.

Transactions of the American Society of Civil Engineers (Volume 81) online

. (page 20 of 167)
Online LibraryAmerican Society of Civil EngineersTransactions of the American Society of Civil Engineers (Volume 81) → online text (page 20 of 167)
Font size
QR-code for this ebook


360


100


640


6.40


60


4


340


40


40


12


480


ITO


720


7.20


50


4


300


50


50


13


600


100


800


8.00
















000


$3 600


$36. CO




100


$600


$6.00









Note. — Average cost per acre for structure and preparation of land for irriga-
tion, say, $6.

It is not claimed that Table 4 is absolutely accurate in any way,
but it shows that, for the average piece of land, the cost distributed
over the whole irrigable area will be about $6 per acre, and that for
the piece where 50% requires the concentrated expenditure (which



232 CLASSIFICATION OF IRRIGABLE LANDS

must be considered a high percentage) the cost per acre in a similar
way will only be about $8.

Since the classification has been completed, this study has been
checked by actual results, and it has been found that the average
total cost per irrigable acre, including the $4 charge for smoothing and
leveling, has been $5.70.

On 8% of the farms the cost was less than $5.



On 60% "






u


u




" between


$5 and $6.


On 22% "






il


a




It il


6


" 7.


On 84% «






a


il




il 11


7


" 9.


On 1% "






il


a




11 11


9


" 10.


On i% "






11


li




il 11


10


'' 12.


Surveys and Plans Eeq


uired





It


was realized that the bs



very complete classification anticipated must be very accurate contour
plans showing the detailed topography of all the area to be classified.
The Canadian Pacific Railway Company was required to furnish the
necessary plans, and as it had made topographical surveys covering
only a small portion of the total area, it was necessary to make new
surveys of the remainder.

The specifications for these plans were as follows:

1. — The scale of the plans shall be 400 ft. to 1 in.

2. — On every plan shall be shown 5-ft. contours in heavy lines,
and wherever the slope is less than 2 ft. in 100 ft., 1-ft. contour lines
shall be shown in thin lines.

3. — All "ring" contours in hollows or on summits shall be located
on the groimd by at least four points.

4. — All sloughs or other areas covered by water shall be located by
at least four points.

5. — The tracings submitted in duplicate to the Comm i ssioner of
Irrigation shall be made from the original plane-table plans made in
the field.

6. — The location and elevation of every field outlet shall be shown
plainly on each plan. The elevation of the field outlet shall be a
point 3 in. below the crest of the measuring weir, if located at or
within the farm boundary ; where this measuring weir is not at or within
the farm boundary, the elevation of the field outlet shall be the eleva-
tion of full supply level in the lateral supplying such outlet.



CLASSIFICATION OF IKRIGABLE LANDS 233

7. — The area and location of such land as is commanded by the
ditches, but which is plainly rendered non-irrigable owing to alkali or
any other cause, shall be shown on the plans.

8. — No contour lines need be shown above the falling contour which
passes through the elevation of the field outlet and falls from it at the
following rates :

(a) Where the natural slope of the ground is less than 0.10 ft. in
100 ft., at a rate not less than 0.05 ft. in 100 ft. ;

(h) Where the natural slope of the ground is greater than 0.10 ft.
in 100 ft. at a rate not less than 0.10 ft. in 100 ft. ;

(c) Where the natural slope of the ground is at or near the
critical slope of 0.10 ft. in 100 ft. at either of the rates men-
tioned in (a) and (b), such as good and reasonable practice
demands.

9. — Every precaution shall be taken to make the plans as accurate
as possible within the limit of a reasonable expenditure of money.
The maximum error in the plans area delineated by the critical con-
tours shall not exceed 2i% in any quarter-section of land.

10. — The exact location of any of the Company's distributaries or
secondary canals which ran through any parcel of land, shall be the
outside lines which determine the land that is made non-tillable by
the ditch construction or other works.

11. — All distinct drainage lines or channels shall be traced on the
ground and shown on the plans.

12. — All plans submitted should be to a standard, over-all size, for
the purpose of filing, and should not exceed 18 by 18 in. This will
permit one section to be shown on each plan at a scale of 400 ft. to
1 in., and one quarter-section at a scale of 200 ft. to 1 in.

13. — It is understood that, under Secondary Canal C, about
90 000 acres of land have already been contoured to a scale of 1 000 ft.
to 1 in. For this particular land. Paragraph 5 of these specifications
shall be inoperative.

14. — It is understood that, under Secondary Canals A, B, and C,
about 100 000 acres of land have already been surveyed to a scale of
200 ft. to 1 in. These surveys do not show contours, but show a
classification of land, based particularly on soil conditions. These
plans with descriptive notes will be accepted by the Commissioner of



234



CLASSIFICATION OF IRRIGABLE LANDS



Irrigation, who will reserve the right to call for such additional in-
formation on any particular plan as he may require for the purpose of
the re-classification.

With reference to Clause 13 of the Specifications, this meant in
practice that the plans submitted were to the general scale of 400 ft.
to 1 in., but were enlarged from the original field plans (at 1 000 ft. to
1 in.) which had previously been prepared by the Company.



Turnout AElev -.3053.3



N.I. Arable loam.



^7
27.4 Acs. -*/






y \ \ s Irrig-able loam. /4






/



^7
/




Fig. 2.



The left half of Plate III shows a typical plan as submitted by the
Company, and Fig. 2 shows a typical plan as submitted under the
special Clause 14 of the Specifications.

The Company has constructed all the canals and ditches which de-
liver the water to the field outlet for each parcel of land. The usual



CLASSIFICATION OF lERIGABLE LANDS 335

parcel to which a delivery is made is 160 acres, this being a legal
quarter-section, the parcel usually dealt with in selling. In making
the classification it was necessary to know the exact parcel of land that
was to be served from any field outlet.

In the case of land already sold by the Company, agreements filed
with the Department showed the parcels owned and included under
each water agreement, and in these cases such areas were considered as
one. In other special cases, usually concerning fractional areas, the
Company's plans submitted showed by a conventional sign the special
parcels that were to be sold together, and were so dealt with as regards
parceling in the classification.

The cost of preparing the plans, imder the general clauses of the
Specifications, was 23 cents per acre, this being based on the total area,
irrigable and non-irrigable, covered by the contour plans.

Procedure of Classification. — The procedure of carrying out the
classification was as follows :

1. — Submission of contour plans by the Company;

2. — Preliminary office classification of plans;

3. — Field classification of plans, including soil analysis;

4. — Final office classification of plans;

5. — Final approval of plans by the engineer in charge.

Preliminary Office Classification. — The Canadian Pacific Railway
Company operates at Calgary a lithographic print process, and, in ad-
dition to the original tracings, supplies an extra plan on paper.

The paper copy of the plan was then classified in the office by pro-
jecting the necessary farmers' ditches from each farm delivery shown
and delineating irrigable and non-irrigable areas in accordance with
the basis of classification decided upon.

The puri)ose of the office classification was to delineate the irrigable
and non-irrigable areas which were dependent on topography, that is,
cost of field irrigating ditches, cost of drainage ditches, excessive
slopes, etc. In addition, there were excluded all areas reserved by the
Company as right of way for main canals, and the areas rendered non-
tillable by the smaller company laterals which ran through any farm
and for which easement had been reserved in the land contract sale to
the farmer.



236



CLASSIFICATIOX OF IRRIGABLE LANDS



in; The results of this office classification were scheduled on a "Land
Classification Detail Sheet", Fig. 3, this sample referring to the right
half of Plate III.

The cost data for ditches, embankments, flumes, etc., used in the
office classification were taken from the standard design sheets which
are shown as Figs. 4, 5, 6, and 7, which were worked up for office use
from the basis of classification determined upon.



LAND CLASSIFICATION DETAIL SHEET
WESTERN SECTION C.P.R.



s


T


R


8


23


Z5



OFFICE CLASSIFICATION


CLASS.


BY


CHECKED BY


APPROVED BV


^. ^.S.


^S


c.aA- %/


R.C.S.
ornCE ENG.



N.W.K

ee./ /7c. /rn'9F^^^T^p;^i=^;¥^-





~'\


A








1


/










1










"il'

1!


._


it

1 c-

1


[J


ff
l|i||i




















■I




^ 1



2. _ «- ■> B

" I. ■=» a

= Sg s

° Il II






242 CLASSIFICATIOISr OF IKRIGABLE LANDS

plan by the use of the letters, Aj B, C, etc., which same letters were
used to denote the segregated areas on the plan.

The right half of Plate III shows the final classification plan
worked up from the plans shown on the left half of that plate (dif-
ferent conventional edgings being used instead of colors). The land
classification sheet referring to the plan shown on the right half of
Plate III is also sho'wai.

With the special plans submitted under Clause 14 of the Specifica-
tions, the result obtained was practically the same, but the procedure
was necessarily somewhat diiferent. These plans showed the result
of a classification in the field by the Company's officials, who had
vvorked under instructions which were practically the same as the
basis of classification adopted. !No contour lines being shown on
these plans, no preliminary office classification was possible, and all
the checking had to be done in the field, which necessitated con-
siderable additional work in determining elevation and delineating
areas by the field assistants. The final classification plan was pre-
pared in the same manner as described above.

Final Approval of Plans and Classification. — The final approval
was made by the engineer in charge after checking the plans to see
that the field notes submitted had been properly interpreted in the
office in making up the final copy. The cost of making the classifica-
tion based on the total area inspected was 16.2 cents per acre, of
which 7 cents is chargeable to office work. Based on the irrigable
acreage only, the cost was 32.9 cents per acre with 14.1 cents chargeable
to office work. These costs included making duplicates of all the
classification maps for special purposes of record.

Personnel. — The work was carried out imder the direct charge of
G. N. Houston, M. Am. Soc. C. E., and Mr. E. C. Spitzer acted
as Office Engineer.



DISCUSSION ON CLASSIFICATION OF IRRIGABLE LANDS 243

disgtitssioin:



T. Kennard Thomson* M. Am. Soc. C. E. (by letter). — This clean- Mr.
cut paper is of especial interest to the writer because he was on the
survey for the first railroad, the Canadian Pacific, to be built in that
section of the country, 33 years ago.

At that time nobody ever expected to see this road pay for itself,
as it was built as a political necessity to keep British Columbia and
the great Prairie Provinces in the Dominion.

An old farmer described the conditions then as follows : "Forty
degrees below zero, 50 miles from water, 500 miles from fuel, God
bless our home."

The paper would be even more interesting, if made a little more
general by stating, for instance, the quantity of water required for
irrigation, and whether the supply is continuous or intermittent during
the summer. As the water comes from the mountains, the writer
assumes that the supply would be*^ cut off by the ice in winter. For
instance, even the Worth Saskatchewan, at Saskatoon, a mighty river
in summer, is practically dry in winter.

It would also be interesting to know what the good and poor lands
sell for, before and after irrigation.

The alkali lands referred to remind the writer that he heard only
last week why his hair had turned white when quite young. It was
discovered, not very long ago, that all young men in the Canadian
Northwest have become white-haired because of the alkali in the water
and also because of the quantity of ammonia used for purifying the
water.

The author states that the climatic conditions are the same as in
Northern Montana, but as the range of temperature is more interesting
than the mean, why not state what they are?

Is it not true that the depth of the rich top soil is 15 ft. or more
in vast areas of the Canadian Northwest ? It may be more modest not
to extol the richness of the soil, etc., but, at the same time, one would
like to know the facts. The price for excavation and fill, 12 cents (as
stated by the author), seems to be remarkably low, especially as the
quantities of material moved in any one spot are so small.

The sections of the cuts and excavations are so small, and the
wooden superstructures are so light, that one wonders if they do
not require very considerable repair every spring.

The Canadian engineers, instead of using blue or black prints on
paper, make black prints directly on cloth, and these can be placed
in a pocket or bag as readily as a handkerchief; and the writer is

* New York City.



Houston.



244 DISCUSSION ON CLASSIFICATION OF IRRIGABLE LANDS

Mr. surprised that such a great improvement has not already been gener-
Thomson. ^^j^ adopted by American engineers.

Table 3, showing the increased value of land each year due to
irrigation — an increase from for wheat to $200 an acre for potatoes —
is exceedingly interesting. In New York State, frost in a single night
will sometimes destroy all the crops; and then a month or more of
good weather will follow with no frosts. Is this the case in Alberta?

Some day it will be possible to generate by electricity sufficient
heat for a night or two to afford sufficient protection from such frosts;
and it will be possible even to go further and, by artificial heat and
light, produce two crops where only one grows now.

Mr. G. N. Houston,* M. Am. Soc. C. E. (by letter). — Irrigation devel-

opment comes under one of two classes: that affecting areas where
irrigation is a necessity, and that affecting areas where it is only
desirable. Irrigation is a necessity where, other conditions being favor-
able, the precipitation is insufficient to produce a profitable crop. It is
desirable where the precipitation, other conditions being favorable, is
insufficient to produce the maximum profitable yield of the particular
crops adapted to the region.

The possibilities under the first class have been about exhausted,
except as the area is extended by conserving the water and rendering
it more efficient in crop production. Under the second class, there
is a great deal yet to be accomplished.

It has not been considered necessary to make any extensive study
of the climatic conditions in connection with irrigation development
in the United States, because the projects have been nearly all con-
fined to the arid and semi-arid districts, where the desirability of
irrigation had been demonstrated in a small way by the individual
farmer, or by the small community of settlers. It was assumed that
like benefits would accrue, in this district, wherever water could be
applied to arable land, and the engineer has been concerned prin-
cipally with transporting and applying this water.

In connection with projects of the second class, however, that is,
where irrigation is not a necessity but is simply desirable for increasing
the yield of an already profitable crop, the development is reaching
out into the more or less humid regions, and the question of desir-
ability is becoming more and more complicated. In these cases a study
of the climatic conditions is necessary, especially with regard to the
precipitation, in order to determine whether the probable additional
profits due to irrigation would be sufficient to justify the cost of the
system.

Monthly averages of the precipitation as published do not furnish
the necessary data for this study. The daily distribution of the rainfall,

* Denver, Colo.



DISCUSSION ON CLASSIFICATION" OF IRKIGABLE LANDS 245

or, in other words, the occurrence of drought periods during the crop- Mr.
ping season, must be considered, as this is the chief factor affecting Houston,
the yield of the crop. In connection with the work of which the
paper treats, the writer had occasion to make such a study of the
climatic conditions of several points in Southern Alberta and Northern
Montana, a summary of which is given in Table 5. A graph was
made showing the daily rainfall during 11 years for each of the loca-
tions, and the drought periods were picked out. Column 1 shows the
length of each period; Column 2 shows the total precipitation which
occurred during each drought; Column 3 shows the number of days
during the drought on which rain fell; and Column 4 shows the
maximum rainfall on any one day during the drought.

The effect which a period of light rainfall may have on a crop
depends on a number of factors, such as the rate of evaporation, as
affected by humidity and wind velocity, the kind of crop and the
stage of its growth, the general texture of the soil, and whether or
not it has had any preparation to receive and conserve the moisture.
These matters must be given due weight in determining the desirability
of irrigation, especially on those tracts where the climatic conditions
are nearly humid.

In the development of irrigation projects, too little attention has
been paid to the character of the soil of the land proposed to be put
under water. This, however, is simply one phase of the general



Online LibraryAmerican Society of Civil EngineersTransactions of the American Society of Civil Engineers (Volume 81) → online text (page 20 of 167)