7720

• UCREFRP Catalog Number: 7720
• Author: Sinning, J. A. and J. W. Andrew
• Title: Habitat Enhancement for Colorado Squawfish in the Yampa River in Conjunction with Railroad Construction
• USFW Year: 1979
• USFW - Doc Type: Mitigation Symposium
• Copyright Material: YES

"

struction of the railroad, a Corps of
Engineers 404 permit was also required. These
approvals also involve the U.S. Fish and
Wildlife Service which was charged with deter-
mination of impacts to endangered species
(Colorado squawfish). Approval from the
endangered species branch of the Colorado
Division of Wildlife was also a requirement.
Liaison with designated representatives of
each governmental agency was initiated early
in the project. Agency representatives were
encouraged to' be present throughout the
field studies and were gathered in several
formal meetings to verify unified approval
of the entire railroad design including the
backwaters. This procedure resulted in
minimal friction and misunderstandings
between all parties concerned, and it often
provided ideas and insights for avoiding
future problems which have plagued other
mine and/or railroad construction projects.

In spite of careful planning some
problems arose during construction of the
backwaters. Projected loc~tions of fill for
the porous dams did not contain suitable
size material after excavation, and the
required size fill had to be transported
from alternate locations of railroad cuts.
In addition, fill size was not as uniform as
desired, and it is expected that proper dam
operation will not occur until the descend-
ing limb of. the hydrograph. Unusually
severe winter weather neces.sitated placing
fill for one of the dams on ice. In
addition, much of the fill was frozen into
blocks. The result was that one dam was too
porous when water first began to flow

through it. This situation is expected to
remedy itself by natural sediment deposition
during th~ first year following construction
as high water receeds. Because of lack of
adequate rip rap at the dam ends coupled
with abnormally high runoff, the upstream
dam is rapidly eroding at the offshore end
and will probably be breached. This will
require repair and possibly the. backwater
channel morphology will have to be re-
adjusted to regain the design shape and
thalweg elevation.

Actual squawfish rearing is expected to
be conducted by the Colorado Division of
Wildlife. Because it was expected that
backwater morphology would not be completely
stable during the first year of existence, a
decision was made early on to wait until the
second year of backwater existence (19~
water year) before attempting squawfisEP
rearing experiments. In. view of the con-
struction difficulties and abnormally high

spring flows during 1979, this appea rs to
have been a wise decision.

Once the porous dams have been properly
stabilized and repaired (during 1979 low
water), rearing experiments can begin.
Because of the amicable relationship estab-
lished between the coal company and govern-
ment agencies and maintained throughout the
period of construction, it is anticipated that
a series of fruitful squawfish rearing
experiments will result which would not have
occurred had the rail spur not been
constructed.

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