2 54 
Journal of Agricultural Research 
Vol. XI, No. 6 
winter rainfall be light. The seepage is doubtless nearly constant so 
that during the months of small rainfall it forms a relatively large portion 
of the total run-off. The drainage water is collected by a few large 
canals (not many small ditches were cut when records were started) and 
discharged by gravity into the city drainage canal. The water was 
measured by means of a weir and a water register placed in the outfall 
canal. 
Conditions from 1909 to 1912, inclusive. —During these years the 
area of cleared and cultivated land was increased so that by the end of 
1912 the area well drained was about 400 acres. The remainder of the 
area was not completely ditched. Such water as entered the main 
canals was discharged promptly. 
Conditions during 1913.—The area ditched and cultivated or im¬ 
proved as residence property was increased during the year to about 500 
acres. Owing to further ditching the area tributary to the main outfall 
canal was estimated at 1,180 acres after January 1, 1913. On October 
25 the weir was placed farther down the main outfall canal, thus increas¬ 
ing the total area above the weir to 1,255 acres. 
Conditions during 1914 and 1915.—During these years the area of 
drained and improved land was gradually increased. By the end of 
1915 nearly all the area had been ditched and about 75 per cent had been 
cleared. About 300 acres had been improved with residences and side¬ 
walks. A part of the remaining cleared land was under cultivation. 
The amounts of water appearing in the column headed “Run-off” in 
Table IV represent the actual water that found its way into the main 
canals. These canals were of such size that water was discharged very 
quickly after it had once reached them. It was only during very extreme 
drouths that a small amount of water at least was not flowing over the 
weir. If the same area had been drained by a pumping plant, the run¬ 
off during these days of such small flow would have been combined in 
two or three days in the month, and the total quantity of water pumped 
would have been less, as the evaporation from the open canals would 
have been greater. This is shown by the fact that on the pumping 
districts the water in the canals is often lowered by evaporation alone 
during dry times. 
UNIT NO. I, POYDRAS, DA.—AREA, 2,500 ACRES. 
This district fronts on the Mississippi River about 20 miles below New 
Orleans, near the little town of Poydras, St. Bernard Parish. About 
500 acres of the front portion were originally covered with a light growth 
of timber; the remainder was a part of the open grass-covered prairie 
typical of that section of the State. The top 3 or 4 feet of the soil in the 
prairie have a very high percentage of vegetable material, and would 
be classed as muck. This muck, however, is not as turfy as that originally 
on the Smithport tract or the districts around Raceland, and seems to 
have a higher percentage of river silt. The subsoil is Sharkey clay. 
