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.' Design Memorandum No.1 - Hydrology," dated 10 April 1964. The 6- hour rainfall amounts were distributed in accordance with letter SWDED-XW subject: "~Iaximum Six-Hour Rainfall Distribution of the Standard Project and Probable Maximum Storms," dated 15 Febrllnry 1974. . 36. PROBABLE MAXIMUM FLOOD. The probable IMximllm flood for Fountain Creek was developed by applyin!'; probable mnximum ex"eflfl rainfall to the basin's unit hydrop,rsph. The total drninar,e Area, including areas above 9000-foot elevation, wns aSSllme" to contribute to the PMF. Pertinent Pl'lF data are shown on Plate 22. The PH], hAa a peak discharee of 412,000 c.Ls. and a volume of 355,000 ncre- feet. . 37. MAGNITUDE OF DESIGN FLOODS. The peak discharre for the probable maximum flood at the Fountain Dam site is 412,000 c.f.s. or 449 c.f.s. per square mile. This is compared with maximum experi- enced peak discharp,es on Plate 23. Also plotted are the standard project flood and the maximum experienced flood for Fountain Creek. . 38. 100-YEAR AND 50-YEAR JIYDROGRAPIIS. Studies made to de- velop the 10o-year and 50-year hydro!';raphs indicate that representa- tive hydrographs could he developed by using a combination of peak discharge data from Plate 3 and volume data from Plate 4. The 100- year and 50-year hydrop,raphs were shaped like the SPF hydrogrnph using the peak from the peak-frequency curve and the volume from th" volume-frequency curve. These hydror,raphs are presented on Plnte 24. . . 39. HYDROGRAPHS OF RECORD. The hydrop,rnphs for th" ppr10d or record for Fountain Creek at Pueblo are shown on Plates 25 thro\lp,h 27. . BASIN DESIGN FEATURES 40. GENERAL. The total storage authorized in Fountain Reser- voir is 247,000 acre-feet, consistin!'; of 187,000 acre-feet for flood control; 20,000 acre-feet for recreation; and 40,000 acre-f"et for' sediment reserve. The flood control stora!';e is subject to chnnr,e when detailed standard project flood routinps are mnde with the re- vised hydrology containerl in this report. These rO\ltin!';s wit] be presented in the Part II hydrolopy desir,n memorandum. . . 41. SEDDIENT. The Alhu<luerque District initinterl n sllspt'nded sediment samplinp prORram for the upper Arkansas River in Colorndo in 1938. Daily samples were taken on Fountain Creek at Puehlo from water year 1942 through water year 1953, inclusive. Intermittent samples were taken on Fountain Creek at Fountain from water year r. 16 .