34 
BULLETIN 1017, IT. S. DEPARTMENT OF AGRICULTURE. 
48 hours. The run-off from this storm raised the water in Lake 
Traverse approximately 2 feet but did not materially increase the 
discharge from the lake. 
- The effect of the two storms of June 10-13 and June 26-28, 1915 
(fig. 14), is quite marked in the run-off records of Red River at 
Fargo, Grand Forks, and Emerson. The monthly precipitation for 
June of that year was maximum. Apparently this was largely due 
to these two storms which covered large areas in the central portion 
SOUTH DAKOTA 
Fig. 11. — Maximum 6-day storm rainfall on watershed of- Eed River of the North, 
July 17-22, 1897. 
of the watershed above Grand Forks. The run-off for the following 
month was very close to maximum at that station. Investigation 
of the monthly and storm precipitation data (see Table 8, Summary) 
showed that one or more storms occurred during each month March 
to September, inclusive, and that the excessive monthly precipitation 
of this period was due largely to excessive storms. 
In the period 189^1919 excessive storm precipitation, causing 
maximum or nearly maximum monthly precipitation, occurred dur- 
ing each month just prior to the months from May to October for 
which the run-off was maximum above Grand Forks.. Thus May, 
,,i 
