135 



EXHIBIT 10 



FREQUENCY OF 5 YEAR FLOOD EVENT IN URBAN VS FORESTED AREAS 



HSPF SIMULATION OF A SAMPLE BASIN IN SW KING COUNTY 



Number of events (40-year simulation) 



s» 



Five-Year Forested Dischorge 

 Fully Forested Land Cover 





2 4 6 8 10 12 



Number of years bet^veen 5-year floods 



Note: 



Bars show the numbers of yeors separating 

 discharge events of 5-year recurrence or greater. 





14 



Source: Booth, 1991. 



