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<br />!: ',"iI <br /> <br />" <br /> <br />· Letters from the Colorado congressional representatives have been sent expressing concerns <br />regarding the Corps' study activities <br /> <br />· Legislation was enacted by the Colorado State Legislature directing appropriate <br />Departments/Divisions to perform a technical review of the study <br /> <br />· Approximately 300 to 500 homes would be impacted due to the proposed plan of improvement. <br /> <br />· Study delays are causing economic and property value hardships to nearby property owners. <br /> <br />· Adverse impacts to the Cherry Creek School District are expected <br /> <br />· The upper basin dry dam proposal has adverse economic impacts to adjacent property owners <br /> <br />· Why should there be a "zero risk" policy for a PMP event for the downstream floodplain areas? This <br />type of practice is not the standard for any other type of design in any industry. 40,000 people are <br />killed every year in automobile accidents. Why shouldn't we accept the risk (a very small risk) that <br />thousands may die in the event of a catastrophic flood and/or dam break? <br /> <br />· There may be environmental impacts to existing wildlife habitats and State Park features <br /> <br />· Any dam embankment modifications will have adverse impacts (construction related) to the <br />surrounding communities and traffic patterns <br /> <br />Historical data for the Cherry Creek basin: <br /> <br />· Correlation of the 1994 hydrologic analyses to the past major flood events of 1864, 1876, 1885, <br />1912, 1933, 1935, 1955, 1965, and 1973 is needed. The question is how many times greater is the <br />PMF value compared to these historical flood events and to the published 100-year peak flow value. <br /> <br />· The PMP value should be compared to the hydrologic values of the 1935 storm event. It is <br />understood that the 1935 precipitation/flood values for storms along Monument Ridge and the <br />Republican River basin were used for the Cherry Creek basin. <br /> <br />· The original project design hydrology values (original Cherry Creek dam design) should also be used <br />to correlate the PMF analysis. <br /> <br />· Comparison of historical precipitation values compared to the 17 inch value is needed <br /> <br />· Completion of a regional study is needed to determine what is an appropriate PMP to 100-year <br />rainfall ratio. <br /> <br />· Determination of the average percentage of hail vs. the percentage of rainfall in a major storm event <br />should be done. Hail is almost always present in a major event. Extracting the hail values will <br />reduce rainfall values and resulting runoff rates. <br /> <br />· What is the antecedent moisture source for a PMP event and does it assume the maximum rain that <br />can be expected along the Front Range of Colorado? <br /> <br />2 <br />