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Elements common to all alternatives, described in detail in the Final EIS, include: eAdaptive management eFlood frequency reduction measures eNew population of humpback chub eEmergency exception criteria eMonitoring and protecting cultural resources eBeach/habitat-building flows eFurther study of selective withdrawal Habitat maintenance flows, designed to reform backwaters and maintain sandbars, will consist of high, steady releases within the powerplant capacity of 33,200 cfs for one or two weeks in March, or other months if recommended through the AMP. These flows have been selected to redistribute sediment accumulation in pools and backwaters, rebuild portions of sandbars above the normal peak stage, and prevent return channels from becoming dominated with vegetation. Habitat maintenance flows, defined as steady flows with minor fluctuations of up to .I-. 1 ,000 cfs, would permit limited voltage regulation within the power grid. The month of March was selected to allow backwater channels to reform prior to the humpback chub spawning period and because more sediment is likely to be supplied by tributary flow in March than later in the spring. Habitat maintenance flows would not be scheduled when the projected storage in Lake Powell on January 1 is greater than 19 million acre-feet (maf). Annual release volumes under such conditions are typically greater than the minimum annual release volume of 8.23 maf, and such flows already may be near or exceed powerp/ant capacity. Maintenance flows would begin by increasing flows at a rate no greater than 4,000 cfs per hour and would conclude by decreasing flows back to the normal operating range at a rate no greater than 1,500 cfs per hour. The limit on daily change in flow would not apply during these transitions. Habitat maintenance flows would differ from beach/habitat-building flows because they would be within powerplant capacity and would occur nearly every year when the reservoir is low. Beach/habitat-building flows would be less frequent. Habitat maintenance flows would not occur in years when a beach/habitat-building flow occurs. Neither of these special releases would be scheduled in a year when there is concern for endan- gered fish or other sensitive resources. 38 ,