WSP08399

• File Number: 8220.101.10
• Description: Glen Canyon Dam/Lake Powell
• State: AZ
• Basin: Colorado Mainstem
• Date: 10/22/1998
• Title: Briefing Paper on Grand Canyon Adaptive Management Program
• Water Supply Pro - Doc Type: Report/Study

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may not be met by the operation of the preferred Alternative in which case
the M.O.s are revised or the Preferred Alternative Operation is revised.
The Information needs are data and information needs that are required for
achieving the M.O.s. These include information and data on endangered
species, sediment resources, water quality, etc.
. M.O. and Info Needs were approved by AMWG at its July 1998 meeting
. Subject to review and modification as necessary
Beach Habitat Maintenance Flows (BHMF)
. Flows up to power plant capacity (32,000 cfs) to maintain beaches and
backwater habitat
Beach Habitat Building Flows (BHBF)
. Flows greater than power plant capacity (up to 45,000 cfs), requires power
plant bypasses
. Originally to be implemented when Lake Powell was low; as a result of
State opposition BHBF will be implemented when Lake Powell is full as a
spill avoidance measure,
BHBF Hydrologic Trigger Criteria
. TWG developed and AMWG approved criteria under which a BHBF
could be implemented; Secretary needs to approve
BHBF Resource Criteria
. Developed by GCMRC and accepted by TWG
. Method for evaluating impacts ofBHBF on resources for January - July
period
. Criteria to be applied in 1999; subject to refinement as additional
knowledge is gained
. Both Hydrologic and Resource Criteria must be met before a BHBF can
be implemented
Flood Frequency Reduction Measures
. Original concept was to reduce flows greater than 45,000 cfs to 1 in a 100
yrs. through providing an additional 500 KAF of storage space in Lake

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