FLOOD05740

• County: Denver
• Community: All
• Stream Name: All
• Basin: South Platte
• Title: Landslide Loss Reduction
• Date: 1/1/1989
• Prepared For: State of Colorado
• Prepared By: CGS
• Floodplain - Doc Type: Educational/Technical/Reference Information

Communities that have landslide prob-
lems are encouraged to assess the costs of
damage to public and private property and
weigh those costs against the costs of a land-
slide reduction program. The prevention of a
single major landslide in a community may
more than compensate for the effort and cost of
implementing a control program (Fleming and
Taylor, 1980, p. 20).

Avoiding the costs oflitigation is an addi-
tional incentive to undertaking a local program
of landslide hazard mitigation.
When landslide disasters do occur, the ex-
istence of a program for loss reduction should
help ensure that redevelopment planning takes
existing geologic hazards into account.
In the U.S., only a few communities have
established successful landslide loss reduction
programs. The most notable is Los Angeles,
where, as mentioned above, loss reductions of
97 percent have been achieved for new con-
struction since the implementation of modern
grading regulations (Slosson and Krohn, 1982).
In communities that have achieved loss
reductions, decisions about building codes,
zoning, and land use take into account identi-
fied landslide hazards. The U.S. Geological
Survey (1982) has found that these communi-
ties have in common four preconditions leading
to successful mitigation programs: (1) an
adequate base of technical information about
the local landslide problem, (2) an "able and
concerned" local government, (3) a technical
community able to apply and add to the tech-
nical planning base, and (4) an informed pop-
ulation that supports mitigation program ob-
jectives. While the technical expertise to reduce
landslide losses is currently available in most
states, in many cases it is not being utilized.
Still, the success of loss reduction measures
clearly depends upon the will ofleaders to
promote and support mitigation initiatives.

Local Government Roles
At the local government level, hazard mitiga-
tion is often a controversial issue. Staff and
elected officials of local governments are
usually subjected to diverse and sometimes
conflicting pressures regarding land use and
development. Local officials, as well as build-
ers, realtors, and other parties in the develop-
ment process, are increasingly being held liable

for actions, or failures to act, that are deter-
mined to contribute to personal injuries and
property damages caused by natural hazards.
Consequently, a modefcommunity landslide
hazard management planning process should
encourage citizen participation and review in
order to identifY and address the perspectives
and concerns of the various com. munity groups
. . .
affected by landslide hazards.
Because most landslide damages are relat-
ed to human activity-mainly the construction
of roads, utilities, homes, and businesses-the
best opportunities for reducing landslide
hazards are found in land-use planning and
the administration and enforcement of codes
and ordinances.
The vulnerability of people to natural haz-
ards is determined by the relationship between
the occurrences of extreme events, the proximi-
ty of people to these occurrences, and the
degree to which the people are prepared to cope
with these extremes of nature. The concept ofa
hazard as the intersection of the human sys-
tem and the physical system, is illustrated in
. Figure 5. Only when these two systems are in
conflict, does a landslide represent a hazard to
public health and safety.

Figure 5. The relationship of people, land-
slides, and hazards (modified from Colorado
Water Conservation Board et al., 1985).

The effectiveness oflocallandslide mitiga-
tion programs is generally tied to the ability
and determination oflocal officials to apply the
mitigation techniques available to them to
limit and guide growth in hazardous areas. A
list of 27 techniques that planners and mana-

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