[ 39 ] 
The Silt Problem and Storage Reservoirs. 
7 
that it is probable that the mean results would fall below those found 
as above. 
From August, 1899, to July, 1900, inclusive, the discharge of the 
Brazos river amounted to about 7,570,000 acre feet, while the calculated 
amount of silt during the same time was 95,740 acre feet, as computed 
from a week’s settlement. During September, 1899, the discharge of 
water was about 30,000 acre feet with only about seventy-one acre feet 
of silt, while in February, 1900, the water discharge amounted to about 
96.000 acre feet, but was clear all month, so that practically no silt 
passed. During April, 1900, the water discharged amounted to over 
2.600.000 acre feet with over 49,000 acre feet of silt. For May of this 
year the water discharged amounted to about 2,044,000 acre feet with 
21,660 acre feet of silt. During April two overflows occurred, one of 
these extending over into May, and for these two months an immense 
amount of red colored water passed down. No attempt was made to 
measure the flow during these floods except for the immediate channel 
of the river. The water stretched for miles across the overflowed bot- 
toms, in many places having a strong current, so that probably much 
more water passed down than is here estimated. No discharge measure- 
ments were made at the very highest stages of the river, but I got one 
measurement very near the highest stage reached this year, the discharge 
then being 123,700 cubic feet per second. This measurement was taken 
on April 29. The lowest discharge measurement made was on September 
10, 1899, and amounted to only 574 cubic feet per second. The gauge 
reading for this small flow was 1.7 feet and as this fell to 1.3 feet later 
on in the month the minimum discharge probably dropped as low as 300 
cubic feet per second. 
During the great flood of 1899 the river was two or three feet higher 
than for either of the overflows in 1900, and whereas the highest dis- 
charge for the latter year amounted to about 125,000 cubic feet per sec- 
ond, in and immediately adjacent to the channel of the river, it is prob- 
able that during the highest stages of the flood in 1899 the discharge 
within the channel may have reached 160,000 cubic feet per second. 
Add to this the flow that must have occurred across the overflowed bot- 
tom — a width of perhaps six or seven miles — and it is possible that the 
total discharge may have reached the enormous amount of 250,000 cubic 
feet per second. As to what this amount of water means it will be suffi- 
cient for those who witnessed the failure of the Austin dam to state that 
for a depth of 11.07 feet on the crest — the depth carried at the time of 
failure — the discharge was about 135,000 cubic feet per second. The 
Brazos river stood for days with a depth of about fifty feet above low 
water mark and a velocity of eight or nine miles per hour. 
At such very high stages of the river it was no easy matter to measure 
the velocity, for the current meter could not be lowered to the bottom. 
