MINIMUM FLOW — COMMENTS REQUESTED
Key Findings: Minimum Flow
Analyzing the Costs & Benets
Supplemental Environmental Impact Study
The Corps’ Supplemental Draft Environmental
Impact Study (SDEIS) lays out predicted effects of the
projects, the extent to which the project objectives
would be achieved, and costs/benefits.
The study evaluates a “reallocation” of the
reservoirs from their current purposes:
White River: Five feet would be added to Bull
Shoals Lake’s current “conservation pool” level by
removing that water from the lake’s “flood pool.”
The additional conservation pool water would be
utilized to quadruple the current 210 cfs minimum
flow to 800 cfs, except during drought periods.
Norfork River: 3.5 feet of minimum-flow water
would be secured by reallocating 1.75 feet from
the lake’s current flood pool, and 1.75 feet from
its current conservation pool. The current 115 cfs
minimum-flow would be almost tripled to 300 cfs,
except during drought periods.
White River Quality:
• Minimum flow increases from 210 to 800 cfs
•
•
•
(flows under 1,000 cfs best for all except adult
rainbows)
Dissolved Oxygen increases but not necessarily
year-round
Water to be about 6-7 degrees cooler at mile
388 (Buffalo River confluence) during hottest
June periods; more difficulty below Calico Rock
during extreme heat under 3,000 cfs
Minimum flows likely suspended about 2.3%
of days (in droughts when conservation pool
emptied)
Norfork River Quality:
• Minimum flow increases from 115 to 300 cfs
• Dissolved Oxygen increases but not necessarily
•
•
year-round
Temperature cooler
Minimum flows likely suspended 10.1% of days (in
droughts when conservation pool emptied)
Trout Food Production
• White: “wetted area” increases 33%; increased
•
•
production of invertebrate and other trout foods
Norfork “wetted area” increases 53.7%
Increases in duration of larger “wetted areas”
in both tailwaters magnifies the effect of more
areas
Wading Conditions
• White: minimum depth increases about 7”, with
•
wading difficulty increased about 35% (velocity
x depth)
Norfork: increases about 5”
Infrastructure
• Bull Shoals Dam could accomplish via use of
•
main turbine
Norfork Dam would require additional
infrastructure
•
•
Send Comments to Support Minimum Flow
Written or email comments accepted
Comments in support of the project may
help build mobilize required federal funding for
infrastructure and utility compensation.
Send comments by mail to:
Mike Biggs, PE, Water Resource Manager
U.S. Army Corps of Engineers
PO Box 867
Little Rock, AR 72203-0867
Easy way to email comments:
Email your comments directly to the Corps by
clicking the appropriate link on our homepage:
www.friendsoftherivers.org
You will have choices of comments, which you can
then edit. Or you can write from scratch.
Benefits-to-Costs Ratios:
• Excludes initial costs
• Bull Shoals: 11.78
• Norfork: 1.39
“Conserve - Restore - Enhance”
www.friendsoftherivers.org
Friends of the North Fork
and White Rivers, Inc. is
an Arkansas non-profit
organization -- 501(c)(3)
-- devoted to creating an
ongoing dialogue where
individuals, groups, and
government agencies
can work together to
conserve, restore and
enhance these beautiful
rivers.