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, 1896, 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 \( 



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. 



