EP 1165-2-1
30 Jul 99
storage enough to cause the same impacts downstream as a channel.
13-7. Nonstructural Measures. Section 73 of Public Law 93-251
expresses Congressional policy and, in effect, endorses Corps practice
that consideration shall be given to nonstructural measures in the
planning and formulation of all flood damage reduction plans.
Nonstructural measures are defined as those which reduce or avoid
flood damages, without significantly altering the nature or extent of
flooding, by changing the use made of flood plains or accommodating
existing uses to the flood hazard. Examples of nonstructural measures
are flood proofing, flood warning/preparedness, temporary or permanent
evacuation, and regulation of flood plains. These measures are
considered separately, in combination and as incremental elements of
plans which may include structural measures also. Economic
justification can be based on combined flood damage reduction and
other (e.g., recreational) benefits. Nonstructural plans should be
formulated without preconception as to what would constitute an
acceptable minimum level of protection. The level of protection may
vary in order to achieve a more coherent and cohesive plan. The level
of protection is a Corps decision; individual owners may decide
whether to participate. Plans that would leave occupied buildings
inaccessible during a flood are normally not recommended. The
separable costs allocated to recreation and fish and wildlife shall
not exceed the costs for flood damage reduction.
13-8. Definition of the Flood Control Plan. The Federal flood
control project is comprised of two obvious elements: the physical
aspects of improvement recommended and the associated requirements of
local cooperation. The intended flood control plan (i.e., the outputs
from the Federal project) may, however, be dependent upon other
elements as well. The assumptions made about how the Federal project
improvements will function may depend upon other assumptions about the
continued effectiveness of already existing non-Federal developments
that shape or control flows (whether specifically intended for flood
control, or not). They may reflect the assumed existence of other
non-Federal developments planned but not yet in place. It is critical
that the non-Federal sponsor, responsible for operation and
maintenance (O&M) of the Federal project, understand the importance of
all the elements that go together to make the plan function. A
complete description of a plan includes all structural, nonstructural,
legal, and institutional features, both proposed and existing, that
contribute to the intended flood control outputs. The outputs of the
plan, and of individual elements if they have separable outputs,
should be quantified in understandable physical, economic and
environmental terms. The operating requirements should be developed
for each element requiring operation (e.g., statement of the trigger
that will say it is time to close a gate and the amount of time it
will take to close it). Finally, there should be explication of the
overall resources required to operate and maintain the plan, i.e.,
manpower, equipment, cost. The requirement for definition of the plan
in these terms begins in the preauthorization feasibility phase and
ends with preparation of the O&M manual furnished to the non-Federal
sponsor when the project is turned over (See paragraphs 10-12,
11-2.c).
13-9. Drainage. Section 2 of the Flood Control Act of 1944 redefined
flood control to include "channel and major drainage improvements."
Section 403 of WRDA 1986 modified this by inserting after "drainage
improvements" the following: "and flood prevention improvements for
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