180 The Small Reservorr. 
feet, and seven feet deep, or double that width if the depth is 
decreased one-half. The shallower itt can be made the better, 
for many reasons, but especially on account of the temperature 
of the water. That of springs is generally too low in summer 
for immediate use, and its value is greatly enhanced by being 
raised to an equal or greater temperature than that of the air. 
This is quickly done by exposure in a shallow pond. A reser- 
voir can be constructed entirely in the ground where the slope 
will admit of it, and by lining the bottom and sides with clay 
well puddled, will answer for most purposes. Some are built 
of adobe, backed with earth and plastered on the inner side 
with hydraulic cement. Concrete of lime, sand, and broken 
stone, is, however, the best material, where lime can be readily 
obtained, and any person with ordinary mechanical skill can 
construct them. The following hints on a dirt reservoir may be 
suggestive :— 
A reservoir should be built on the highest part of the tract sought to 
be irrigated by scraping the earth from the outside and from such a large 
area as not to affect the utility of the land trom which it is taken. With a 
levee all around 5 feet high, 4 feet of water could be carried safely. The 
slopes ought to be two to one on the inside. A reservoir 20 feet square 
and 4 feet deep would hold 12,000 gallons. With the slopes as above the 
reservoir should be measured 2 feet from the bottom, or half way up the 
4 feet of water; consequently to lay out a reservoir to hold 12,000 gallons, 
put the stakes 12 feet square and build. For any other sized one take 8 
feet off the same asin this. A reservoir 25 feet square will hold 18,750 
gallons and would be 17 feet square at the bottom; one 30 feet square 
would hold 27,000 gallons and would be 22 feet at the bottom; one 35 feet 
square--27 at the bottom—will hold 36,000 gallons; one 4o feet square—32 
on the bottom—will hold 48,000 gallons. This spread upon the surface of 
an acre would be alittle more than 13{ inches of rainfall. 
Almost any loam soil will hold water with a little puddling. The 
cheapest way to puddle is to build a pen the size of the intended reservoir, 
including at least a portion of that to be under the embankment, wet it 
very wet, put some hogs in the pen and keep feeding them barley, a little 
at a time, so as to make them not only walk around but root for the barley. 
A half sack of barley fed to eight or ten hungry hogs in half a day will 
make a good puddle. If it did not work satisfactorily the water could be 
taken off and the bottom covered about an inch deep with coarse sand 
mixed one part to five with Portland cement, put in dry, and let it be cov- 
ered slowly. A barrel of cement may be counted at about 4 cubic feet and 
with the mixture above would cover the first-named reservoir about 13¢ 
inches. This would make it tight. The supply pipe should come up from 
ae bottom, so that the lift would never be more than the height of the 
surface. 
Loss of Water by Seepage-—The great loss of water by 
seepage during a long run has led to the cementing of ditches, 
and to the use of miles of large wooden, concrete and iron pipe 
by the irrigation, companies of southern California; also, where 
the slope is rapid, paving ditches with rock has been resorted 
*Wiull S. Green, of Colusa. 
