7912

• UCREFRP Catalog Number: 7912
• Author: Tennant, D. L.
• Title: Instream Flow Regimens for Fish, Wildlife, Recreation and Related Environmental Resources.
• USFW Year: 1975.
• USFW - Doc Type: Billings, MT.
• Copyright Material: NO

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it approximates the end of the growIng season; c) There is a mini.nn.nn
probable error due to the effect of ice in the records of winter flow
if the discharge for the winter period (November to April) is computed
together at one time; d) The winter or base flow period coincides
with reduced metabolic functions and decreased demands for vital life
elements by most aquatic organisms (e.g., oxygen, food, removal of
waste products, and increased tolerance to pollution); e) A low flow
winter period ~tches the downstream migration habits of many fishes
(warmwater and coldwater), when they travel to deeper more permanent
water to spend the winter. This is also the spawning and incubation
season for most salmonids, when they naturally seek less water by
moving into headwater or tributary streams and onto redds in shoal
or shallow riffle areas; and f) Higher summer flow regimens provided
by this method coincide with the frost-free, recreation season and
the major growth period for most aquatic plants and animals, when their
requirements for dissolved gases, space, food, and removal of septic
waste products are naturally higher (the attendant increased width,
depth, and velocities in the stream all serve to enhance the availa-
bility of elements vital to these recreation uses and critical life
functions). These phenomena may be seasonally reversed for anadromous
fishes using the coastal streams of Alaska, the Canadian Provinces, and
our west coast states and flow regimens should be adjusted accordingly.

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Using the ~ntana Method, it is easy to adjust to above or below
normal water years and maintain stream flows that are appropriate
portions of monthly, quarterly, or annual instream supplies of water.
This helps fish, wildlife, and aquatic resources share surpluses and

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