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Saca County 4.1.4.2 Estimated Point Precipitation Return Periods The estimated precipitation return periods in Baca County are presented in Table 4.1-4. The 6-hour, 12-hour, and 24-hour storm durations for the 10- year and 100-year return interval were taken from the maps and nomogram provided in NOAA Atlas 2, Precipitation-Frequency Atlas of the Western United States, Volume ill - Colorado (1973). Table 4.1-4 10-year and 100-year Point Precipitation Values for Various storm Durations Storm Duration 10-vr Precinitation 100-vr Precipitation 6 hours 3.3 inches 5.2 inches 12 hours 3.8 inches 6.0 inches 24 hours 4.2 inches 6.8 inches As noted earlier, the magnitude of precipitation that fell over Baca County in July and August of 1997 did not produce the damaging floods experienced in other counties; instead, the damage was the result of the frequency of storm events over a short time (August 5 through 12). Consequently, none of the rainfall totals exceeded the 100-year estimates. Table 4.1-5 shows rainfall amounts, duration, and comparison with lO-year estimates for all four storm events that produced over one inch of rain. Table 4.1-5 Summary of,Storm Precipitation, Duration, and Return Period for Baca County Maximum Estimated Point Return Source Location Date PreciDitation Duration Period Colorado Springfield July 29 1.13 inches 24 hours <10-year, Climate 24-hour Center 1998 event Colorado Stonington August 5 2.46 inches 8 hours <lo-year, Climate 6-hour Center 1998 event Colorado Walsh , August 5 2.17 inches 24 hours <lO-year, Climate 24-hour Center 1998 event Colorado Walsh August 9 1.52 inches 24 hours <10-year, Climate 24-hour Center 1998 event Colorado Campo August 11 1.13 inches 24 hours <lo-year, Climate 24-hour Center 1998 event ~ I d479/chap4.1.doc 08117/98 4.1-7