OVERFLOW OF RED RIVER OF THE NORTH. 
35 
1896, July, 1897, and September, 1900, months of maximum precipi- 
tation, were followed by months of maximum run-off, June, August, 
and October, respectively. Again during May, 189G, and May, 1904, 
the run-off was near the May maximum for the period 1894 to 1919, 
because of storms in April and the first half of May in each of 
those years. 
Maximum run-off during July, 1916, at Grand Forks was due to ex- 
cessive storm precipitation in June and to heavy monthly precipi- 
SOUTH DAKOTA W L/L^X^ 
Fig. 12. — Maximum 4-day storm rainfall on watershed of Red River of the North, 
July 1-4, 1919. 
tation (approaching maximum) for June and July. Maximum run- 
off during September, 1905, was due largely to heavy storm precipi- 
tation during the last half of August over the central portion of the 
watershed. 
Thus it appears that maximum monthly precipitation due largely 
to excessive storm precipitation over a considerable portion of the- 
Red Eiver watershed, during the months April to October, has 
materially increased the run-off from the watershed ; however, maxi- 
mum monthly precipitation may produce in the following month 
run-off approaching maximum even though no maximum storm 
precipitation occurs. 
