OVERFLOW OF RED RIVER OF THE NORTH. 
27 
plotting the average precipitation at stations having records covering 
10 or more years. The maximum and the mean annual precipitation 
as indicated on figures 6 and 8, respectively, have been greatest in 
the southeastern portion of the watershed and have diminished in in- 
tensity to the west and north. 
Average depths of monthly and annual precipitation in the seven 
subdivisions (see fig. 5) of the watershed for the period 1892 to 1919 
were computed. The depths averaged were measured at from 2 to 
Fig. 6. — Total precipitation during 1896 on watershed of Red River of the North. 
12 weather observation stations in each sub-area. The total volume of 
precipitation for maximum months and for months immediately pre- 
ceding months when run-off above Grand Forks has been maximum 
are shown in figure 9. 
As is indicated in the various figures and tables, maximum precipi- 
tation for April, May, and November occurred in 1896 when the 
annual precipitation was maximum. In 1900 occurred the maximums- 
for August and September but the total precipitation for that year 
was considerably below the maximum. In no case has the maximum 
for more than one of .the remaining seven months occurred in a single 
year; each has occurred during a year for which the annual precipi- 
tation was above the mean for the watershed. 
