120 FLORIDA GEOLOGICAL SURVEY

the total Green Swamp area could reduce floods in the Hillsborough
River would be by the impoundment of all the discharge that drains
through the Withlacoochee-Hillsborough overflow channel al
station 39.
 Hydrographs of mean daily discharge for Withlacoochee-
Hillsborough overflow, Hillsborough River near Zephyrhills, and
Hillsborough River near Tampa for the flood of March 1960 are
shown in figure 55. The hydrographs were plotted using mean
daily discharges at the gaging stations. The discharge at the
Tampa station was slightly regulated by the waterworks dam but
the effect is not apparent on the mean daily values of discharge.
The peak discharge at the Zephyrhills station, which is 2 miles
downstream from Blackwater Creek, occurred on March 18, the
same day as the peak from Blackwater Creek. The peak discharge
at Withlacoochee-Hillsborough overflow occurred on March 19 while




 13 doay



 t200\ Hillsborough River
 near Tampa






 ,2 days

 6000-- --------
 Hillsborough River
 SI / near Ztphyrhills

 Ai ___________


 13 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
 Morch 1960
Figure 55. Hydrographs of mean daily discharge for three Hillsborough
 River gaging stations, flood of March 1960.