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<br />. <br /> <br />. <br /> <br />. <br /> <br />G02733 <br /> <br />near full condition through the mid-1990s and possibly <br />beyond, periodic flood control releases may be required <br />during this time, and any reduced flood forecasting <br />capabilities would pose increased risks to those along the <br />Colorado River. <br /> <br />RECOMMENDATlON <br /> <br />ff.I~ is strongly recoImfmend~ed ~hat the Congress pcovifde ~~ <br />SU lClent annual federa un 109 1n 1990 and thereafter or /' <br />the full operation and maintenance of the National Weather <br />Service's Colorado River Flood Warning System. <br /> <br />IV. ISSUE <br /> <br />The existence of hazardous river navigation conditions <br />and damage to public and pc ivate property, river bank D" <br />stabilization and erosion control works caused by power boats <br />when river flows are over 28,000 cubic feet per second (cfs). <br /> <br />DISCUSSION <br /> <br />Since the closure of Hoover Dam in 1935 and until 1983, <br />monthly average river flows in the lower Colorado River have <br />exceeded 28,000 cfs on only one occasion. Flood control <br />releases from Davis Dam in excess of 28,000 cfs are about <br />5,000 cfs greater than daily peak releases for power,~ <br />generation and nearly twice the maximum monthly average <br />release for downstream ....ater needs. Flows over 28,000 cfs <br />will sometimes cover channel training structures and create <br />navigational hazards. In addi tion, waves generated by power <br />boats operating on the river during these flow levels can and <br />do cause severe river bank and structure damage. <br /> <br />RECOMMENDATION <br /> <br />For purposes of public safety and protection of <br />property, it is recommended that the United..st-ates"'Cocfst <br />Guard-make...deter mi na t.ions-as-to..the-aposs t ble..restr_ict ion of <br />the ri~~r.~to.navi9ation ....hen.flood contror"releases-fcom <br />Davis Dam....exceed-28~OOO cfs. -In this regard, it is <br />recommended that the Bureau ot. Reclamat.ion...be required.....as_ <br />part of its ..emergency notification and coordination <br />procedures, to notify the Coast-Guard, the county sherif~ <br />departments of each county, and the tribal police or the.. <br />tribal official of each Indi:-an reservation in .....hich the <br />Colorado River Floodway is located sufficiently in advance <br />of anticipated releases from Davis Dam or Parker Dam in <br />excess of 28,000 cfs to alIa.... for adequate time to make <br />determinations and public notice of such restrictions. <br /> <br />II 1-9 <br />