Laserfiche WebLink
<br />"' <br />f, <br />, . <br />, <br />" <br />, <br />. <br /> <br />- <br /> <br />Table 4.3. - Continued <br /> <br />I <br /> <br />Hydrologic Magnitude <br />Category (cfs) Discussion! Anticipated Effect <br /> Spring Peak, (Continued) <br />Wet: ~ 55,000 Significant motion is reached in 55% of the Colorado River, creating <br />10% exceedence and maintaining important habitats. for Colorado pikeminnow and <br /> razorback sucker in wide areas of the river. Floodplain habitats will be <br /> extensive, but surface area of those habitats is not quantified. Flows <br /> should exceed 30,000 cfs for at least four weeks to maximize the <br /> availahility of nursery habitats for razorback sucker. <br /> Base Flow <br />Dry; ~2,000, Jul- Backwaters for YOY Colorado pikeminnow will be available, but not <br />90-100% Feb at maximum number or surface area. Low stable flows will provide for <br />exceedence maximum growth ofYOY pikeminnow. <br />Moderately Dry; 3,000 - Backwaters in the lower Colorado River Nursery area should be <br />70-90% 4,000; Jul - maximized in both quantity and surface area. Stable flows will provide <br />exceedence Feb for constant habitats and maximum wanning of water for growth of <br /> Colorado pikeminnow. Stable flows will also provide a variery of in- <br />Average, Dry; channel habitats for use by juveniles and adults of all endangered <br />. species. Pools and slow run habitats will be maximized for winter use <br />50-70"10 of Colorado pikeminnow and razorback sucker. Pools and eddy <br />exceedence habitats will be maximized in canyon reaches for humpback chub. <br />A veragcl Wet; 3,500 - <br />30-50% 4,500; Jul- <br />exceedence Feb <br />Moderately Wet; <br />10-30% <br />exceedence <br />Wet: < 5,000; Backwaters will be fewer and smaller than at lower flows, but they will <br />lO% exceedence Aug - Feb still be available for YOY Colorado pikeminnow to use. Flows sbould <br /> decline to this level gradually, but as soon as possible so that larvae are <br /> not carried downstream of we prime nursery habitats in the lower <br /> Colorado River. <br /> <br />i <br />f <br />I: <br />r <br />I <br /> <br />_ft Final Report <br />January 27, 2000 <br /> <br />4-21 <br /> <br />Chapter 4 <br />