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Gu leh, a~d S"nder5o~ Gu leh all have w~tor stara'Jo reservoirs. These tour streams plus Van Bibber Cre'ck all have d IVer5io~ cana 15 cross- ing them. During ~inor floodina the water stor~ae reservoirs ~nd canals hold a large portion of tho floodwaters making the floOdS fartherdownstreamappeilrespoclilllymTld. Howover,duringtl1e largo floods, the reservoirs ann e~nals fIll qulcidy and ''lust sp; i I w"ter. \;Ith tho stordge spacos full thereisanabruptchangetrom minor to major flooding. generally considered hazardous. Thoseconditlonswouldbo:>producej by large floods at various locations On each of the five streams covered In this report. , . . . . . FLOOD CONTROL AND DEFENSE is Ilmit~ to channel stralghten;ng and enlargement through the more urbanl.ed areas. The channel capacities hilveooon increased by the alterations, but are not adequate to contaIn floods of the size studied in this report. THE CAUSE OF FLOODS on the five streams covered in this report is primarily from high intensity thunderstorms. Thefloodsareespe- ciallyscvere if the thunderstorms followa period of hiqhsnowmelt or prolonged rainy weather. . . . GREAT FLOODS have undoubtedly occurred on the streams covered In thls report, but the events have not been recorded because of the small size of the streams and the lack of extensive urbanization. , . . FLOOD DAMAGES would occur on ""chot tho strcdms tor floods of tho size studied in this report. D';""dg..S would be most ext"osive on Ral stan Creek and Lena Guich because they have th" most urbaniZaTion On the flOOd plains. Damages would re~ult from basement ~nd ground floor flOOding, erosion to streets ~nd yaros, and the deposition of siltanddebris. . . . OIJRATio.'l OF FLOODI~jG is brIef due to the steep slopes and :>mill I 5; le of the drainage areas. Ingeneral,thoduratlonoffloodingwould Increase In the downstrOdm direction due to the flatter channel slopes and the increased si.e of the drainage "rea. . . . HAZARDOUS CONDITIONS occur durl~ flooding because of the rapidly rising streams, high velocities, and deep Ilows. Velocities exceed- ing 3 feet per second combined with depths of 2 feet or more are 2 ; I