Estimating the Costs of 

Landslide Damage in the 

United States 

GEOLOGICAL SURVEY CIRCULAR 832 
COVER: Views of landslide damage that occurred in the San Francisco Bay region during the 

winter 1968-69. (Fred Taylor photos.) 
Estimating the Costs of 

Landslide Damage in the 

United States 

By Robert W. Fleming and Fred A. Taylor 

GEOLOGICAL SURVEY CIRCULAR 832 

1980 
United States Department of the Interior 

CECIL D. ANDRUS, Secretary 

Geological Survey 

H. William Menard, Director 

Free on application to Branch of Distribution, U.S. Geological Survey, 1200 South Eads Street, Arlington, VA 22202 
CONTENTS 

Page Page 

Abstract --------------------------------------------------------------------------- 1 Reexamination of costs of landslide damage in the San 

Introduction --------------------------------------------------------------------- 1 Francisco Bay region (1968-69) ----------------------------------- 12 

Acknowledgments ----------------------------------------------------------- 2 Costs of landslide damage in Allegheny County, PennPrevious studies of costs of landslide damage --------------- 2 

National cost of landslide damage--------------------------- 2 

Costs of landslide damage for smaller geographic 

areas ----------------------------------------------------------------------- 3 

Reduction of the costs of landslide damage ------------------- 3 

Landslides defined ----------------------------------------------------------- 4 

sylvania ( 197 0-7 6) -------------------------------------------------------- 14 

Costs of landslide damage in Hamilton County, Ohio 

( 197 3-7 8) ----------------------------------------------------------------------- 1 7 

Preliminary estimate of costs of landslide damage in 

the Manti, Utah, area (1974-76) ------------------------------- 18 

Landslide damage ------------------------------------------------------------ 4 

Categories of damage costs --------------------------------------------- 5 

Background ------------------------------------------------------------------ 18 

Costs of landslide damage -------------------------------------------- 19 

Method of obtaining cost information ---------------------------- 7 Summary -------------------------------------------------------------------------- 20 

Sources of cost information--------------------------------------------- 8 References cited --------------------------------------------------------------- 21 

Problems encountered----------------------------------------------------- 12 

ILLUSTRATIONS 

Page 

FIGURE 1. Extract from an application for State disaster relief from Contra Costa County, Calif. -------------------------------------- 9 

2. Application for Federal disaster relief from the County of Hawaii, Hawaii---------------------------------------------------------- 10 

3. View of a landslide scarp adjacent to a home in Oakland, Calif.----------------------------------------------------------------------------- 11 

4. Rockfall in Pittsburgh, Pa., that closed Parkway East on April27, 1978------------------------------------------------------------- 15 

5. Cracks in a slowly developing landslide in glacial materials damaging this house and several others in a subdivision in Hamilton County, Ohio-------------------------------------------------------------------------------------------------------------------- 17 

6. Map showing the Manti landslide, Manti Canyon, Utah---------------------------------------------------------------------------------------- 19 

TABLES 

Page 

TABLE 1. Public and private sources of data relating to the costs of landslides in the San Francisco Bay region------------- 8 

2. Estimated costs of landslide damages in the nine-county San Francisco Bay region (1968-69) ------------------------- 13 

3. Sources of information contacted on costs of landslide damage in Allegheny County, Pa. --------------------------------- 16 

4. Types and number of utility companies in Allegheny County, Pa. ------------------------------------------------------------------------ 16 

5. Costs of damage due to landslides in Allegheny County, Pa. (1970-76) ---------------------------------------------------------------- 17 

6. Sources of information on costs of landslide damage in Hamilton County, Ohio------------------------------------------------- 18 

7. Costs of landslide damage in Hamilton County, Ohio (1973-78) --------------------------------------------------------------------------- 19 

8. Sources of information on costs of landslide damage in Manti, Utah-------------------------------------------------------------------- 20 

9. Expenditures by governmental agencies on the landslide in Manti Canyon (June 197 4-August 1976) ------------- 20 

III 

Estimating the costs of landslide damage in the United Strtes 

By Robert W. Fleming and Fred A. Taylor 

ABSTRACT 

Landslide damages are one of the most costly natural 

disasters in the United States. A recent estimate of the total 

annual cost of landslide damage is in excess of $1 billion 

(Schuster, 1978). The damages can be significantly reduced, 

however, through the combined action of technical experts, 

government, and the public. 

Before they can be expected to take action, local governments need to have an appreciation of costs of damage in 

their areas of responsibility and of the reductions in losses 

that can be achieved. Where studies of cost of landslide 

damages have been conducted, it is apparent that (1) costs to 

the public and private sectors of our economy due to landslide damage are much larger than anticipated; (2) taxpayers 

and public officials generally are unaware of the magnitude of 

the cost, owing perhaps to the lack of any centralization of 

data; and (3) incomplete records and unavailability of records 

result in lower reported costs than actually were incurred. 

The U.S. Geological Survey has developed a method to 

estimate the cost of landslide damages in regional and local 

areas and has applied the method in three urban areas and 

one rural area. Costs are for different periods and are unadjusted for inflation; therefore, strict comparisons of data 

from different years should be avoided. Estimates of the 

average annual cost of landslide damage for the urban areas 

studied are $5,900,000 in the San Francisco Bay area; 

$4,000,000 in Allegheny County, Pa.; and $5,170,000 in 

Hamilton County, Ohio. Adjusting these figures for the 

population of each area, the annual cost of damages per 

capita are $1.30 in the nine-county San Francisco Bay region; 

$2.50 in Allegheny County, Pa.; and $5.80 in Hamilton 

County, Ohio. On the basis of data from other sources, the 

estimated annual damages on a per capita basis for the City 

of Los Angeles, Calif., are about $1.60. If the costs were 

available for the damages from landslides in Los Angeles in 

1977-78 and 1979-80, the annual per capita costs probably 

would be much larger. 

The landslide near the rural community of Manti, Utah, 

caused an expenditure of about $1,800,000 or about $1,000 

per person during the period 1974-76. Because a recurrence 

for such a landslide cannot be established, it is not possible to 

develop a meaningful estimate of annual per capita damages. 

Communities are urged to examine their costs of landslide 

damage and to evaluate the feasibility of several alternative 

programs that, for a modest investment, could significantly 

reduce these losses. 

1 

INTRODUCTION 

Natural disasters may bring sudden and appalling destruction to an area, or they may slovrly but 

inexorably take their toll in dollars and spirit. 

Damage from tornadoes and earthquakes is sudden and usually occurs with little or no wrrning. 

On the other hand, prolonged drought or ground 

subsidence may occur over a much longer period 

with equally damaging effects. 

Landslides are disasters that encompas~ both 

extremes: sudden and catastrophic, and slow and 

insidious. About 200,000 people were kfled in 

Kansu Province in China in 1920 when a major 

earthquake triggered massive landslides in extensive deposits of windblown silt. In 1970, a rapidly 

moving debris avalanche, also triggered by an 

earthquake, killed at least 18,000 peo..,le in 

Yungay and Ranrahirca, Peru. Nearly 3,000 

people were killed in Italy in 1963 when a landslide into the V aiont Reservoir caused the impounded water to overtop the dam and produce a 

devastating flood downstream. Other landslides 

have caused damage over a prolonged period. For 

example, a landslide in the Ventura c Hfield, 

California, has been damaging oil wells for many 

years. Roads broken by slow landslide movement 

often have layers of road patching sever~l feet 

thick, representing a significant maintenance expense over many years. 

Understanding the cost and significance of 

natural disasters allows officials at all le~rels of 

government to make decisions about how much 

money should be allocated to disaster prevention 

rather than to repair of damaged facilities and 

disaster relief after an event. Resourc~s for 

research related to natural disasters are limited, 

and priorities for research should be based in part 

on the benefits and costs of such actions. 
This report describes a method developed and 

used by the U.S. Geological Survey to obtain 

estimates of the cost of damage caused by landslides in four locations in the United States. Data 

have been collected in three urban areas and one 

rural area. The urban areas include the San Francisco Bay region, California (1968-69); Hamilton 

County including Cincinnati, Ohio (1973-78); and 

Allegheny County including Pittsburgh, Pa. 

(1970-76). The data for the San Francisco Bay 

region resulted from a reexamination of cost data 

compiled and published earlier by Taylor and 

Brabb (1972). The rural area studied is Manti, 

Utah, and vicinity, where a large landslide in a 

national forest about 6 km (4 mi) from town has 

been very costly in public funds. The studies were 

conducted independently at different times, and 

the reported cost figures have not been adjusted 

for inflation. Strict comparisons of cost of 

damage data from different years should be 

avoided. 

As this report indicates, decisions must be 

made about what actually constitutes a damage 

cost and what does not. Some of the costs 

reported here might not seem legitimate to some 

economists. Other costs, which we decided not to 

include in these estimates because they were too 

poorly defined or might be duplicated in other 

data, could perhaps have been retained. In all of 

our attempts to compile cost-of-damage data, 

when definitive data were not available, we have 

used low estimates of costs and have discarded 

data that could be duplicated. Therefore, even 

though the damage costs are only estimates, the 

totals reported generally should be lower than the 

actual costs incurred. When assumptions are applied that produce speculative totals, the assumptions are specified. 

Individual citizens and public agencies need to 

become more aware of the magnitude of annual 

damage due to landslides and the possibility of 

increased destruction. This report is intended to 

encourage governmental agencies to keep more 

complete records of the occurrence and cost of 

landslides. Such information can be used to 

facilitate comparison of preventive costs and 

restorative costs. 

ACKNOWLEDGMENTS 

We sincerely appreciate the cooperation of 

those supplying the costs-of-damage information 

2 

and introducing us to the landslide problems in 

different areas. Special thanks gc to James E. 

Hough in Cincinnati, William R. Adams, Jr., in 

Pittsburgh, and Charles R. Allred and Earl P. 

Olson of the U.S. Forest Service in Utah. An 

early form of the manuscript benefited greatly 

from a careful review by Earl E. Brabb and John 

T. McGill. 

PREVIOUS STUDIES OF COS .... S OF 

LANDSLIDE DAMAGE 

NATIONAL COST OF LANDSLIDE D 4\.MAGE 

Studies by the U.S. Geological S·1rvey of costs 

of landslide damage have not attempted to obtain 

a total annual cost for the United States. 

However, several estimates of the annual cost of 

damage have been published ove"" the past 25 

years that are probably as accur~te as can be 

obtained using the present data bGse. 

A study by the Highway Research Board in 

1958, based on responses to a questionnaire, 

reported damages in the United S~ates as "hundreds of millions'' of dollars annually (Smith, 

1958). Krohn and Slosson (1976) estimated landslide damage to private property in the United 

States by extrapolating cost of damage in Los 

Angeles to the rest of the country. The extrapolation was made by comparing the percentage of 

the population in the United States living on sites 

with similar landslide potential to Los Angeles 

and assuming that the sites were developed under 

inadequate or nonexistent grading codes. Krohn 

and Slosson concluded that the annual landslide 

damage to private property in the United States 

is about $400 million. 

Schuster (1978) concluded, in a recent evaluation of landslide losses in the United States, that 

direct and indirect losses to public and private 

property exceed $1 billion annually. The total was 

obtained using previously publisl'':!d data combined with new data obtained through interviews 

and correspondence with agencies and organizations having cost information. 

Jahns (1978) examined costs of damage from 

several types of natural disasters for the 50-year 

period of 1925-75. During that period, the combined losses from floods, hurrican~s, tornadoes, 

and earthquakes were nearly $20 billion, unadjusted for inflation. In contrast, ground 

movements of two types, landslides and sub-
sidence, totaled at least $75 billion during the 

same period. 

COSTS OF LANDSLIDE DAMAGE FOR SMALLER 

GEOGRAPHIC AREAS 

The California Division of Mines and Geology 

has estimated that landslide damages for California will cost more than $330 million annually 

during the period 1970-2000 if loss-reduction 

practices in effect in 1970 are not improved 

(Alfors and others, 1973). In the San Francisco 

Bay region, where efforts have been made to identify costs of landslide damage, preliminary 

studies documented $25 million in damages for 

the nine Bay area counties for the rainy season 

1968-69 (Taylor and Brabb, 1972). Within a 

single subdivision in this area, costs totaling over 

$760,000 between 1968 and 1971 were identified 

(Nilsen and Brabb, 1972). 

Landslide-causing storms have plagued southern California for the past three decades, but costof-damage information is incomplete and not 

comprehensive. Damage estimates ~re generally 

only for private property and may include 

damages from erosion, sedimentation, and 

flooding, in addition to the landslide damage. 

Notable landslide events occurred in 1951-52, 

1956, 1957-58, 1961-62, 1968-69, 1977-78, and 

1979-80. Slosson and Krohn (1979) reported that 

the incidence of landsliding in earlier years was 

comparable to that in 1977-78 but that the cost 

of damages in 1977-78 was about seven times 

larger than for previous years. The differences in 

cost of damages were attributed to increased property values and construction costs, a larger 

number of structures exposed to damage as a 

result of development, and greater intensity of 

storms in 1978. Damages in 1977-78 were 

estimated at about $50 million. Damages from 

earlier storms were estimated at $7.5 million for 

1951-52 (Jahns, 1969), $7.5 million for 1961-62 

(Slosson, 1969), and $6 million for 1968-69 

(Slosson, 1969). On the basis of studies in other 

areas by the U.S. Geological Survey, public costs 

of damage probably were at least equal to private 

costs. Therefore, the damage costs from Los 

Angeles, quoted above, should be doubled to produce a better estimate of total cost. 

Tubbs (1974) conducted a study of landslides 

and associated damage that occurred during the 

3 

early part of 1972 in part of west-central King 

County, Wash. He identified 80 landslides that 

caused estimated minimum damage of $250,000. 

The damage estimates were only for restor~ng the 

property as nearly as possible to its origill al condition and did not include decrease in property 

value, emergency repair, costs in time and energy 

to property owners, or any of the other indirect 

costs that might have been associated w~th the 

landsliding. 

Briggs and others (1975), reporting data collected by the Allegheny County Depar'tn1ent of 

Planning and Development, placed B verage 

damages for Allegheny County includin~: Pittsburgh, Pa., for the period 1970-74 at abnut $2 

million annually. 

Other published estimates of costs of landslide 

damage have generally been applied to single 

projects or landslide events. For example. Jones 

and others (1961) estimated that the filling of the 

reservoir behind Grand Coulee Dam in Washington cost at least $20 million in landslide damage 

and avoidance between 1934 and 1952. M~rriam 

(1960), in describing the famous Portuguef9 Bend 

landslide in the Palos Verdes Hills, Calif., noted 

that property damage during the period 1956-59 

was in excess of $10 million. About $5.3 million of 

the damage, recovered by property owners 

through litigation with the county of Los Angeles 

(Morton and Streitz, 1967), became a public 

rather than private cost. 

The above damage studies, particularly those 

in the San Francisco Bay region (Taylor and 

others, 1975; Nilsen and others, 1976), r~vealed 

three facts: First, costs to the public and private 

sectors of our economy due to landslide damage 

are much higher than anticipated. Second, taxpayers and public officials generally are unaware 

of the magnitude of the cost, perhaps because of 

the lack of any centralization of data. Finally, 

incomplete records and unavailability of records 

resulted in lower reported costs than actually 

were incurred. 

REDUCTION OF THE COSTS OF 

LANDSLIDE DAMAGE 

Knowing the costs of damage from landslides 

in the United States is of little value unless the 

costs can be reduced through better and less expensive damage repair and through governmental programs designed to prevent landsliding 
or to mitigate damage that does occur. A wide 

variety of engineering alternatives are available 

to correct landslide problems once they have occurred; however, the engineering solutions are 

usually very expensive and the costs of repair can 

exceed the intrinsic value of the property being 

repaired. Local governments, through planning 

and regulation, have several options to reduce the 

costs of landslide damage. Kockelman (1980) has 

prepared a comprehensive summary of the tools 

that can be used to avoid landslide hazards and 

reduce damage. 

The technology is available to greatly reduce 

losses from landslides by avoiding or preventing 

them. Leighton (1976) estimated that, in California, a reduction in damaging failures of 95 to 99 

percent is technically attainable through the use 

of three levels of investigation: regional, tract or 

community, and site, with progressively greater 

detail being obtained in the investigations of the 

smaller areas. However, solutions to the technical 

problems are only a part of the process of achieving landslide hazard reduction. The political 

problem of transferring the information into a 

governmental system to reduce hazards and 

damages is perhaps more formidable than the 

technical one. Requirements for technological 

solutions to landslide problems are subject to 

resistance or pressures from groups that dislike 

regulation or interference, that do not consider 

landslides amenable to loss-reduction measures, 

or that do not consider landslides a serious 

enough economic problem to justify the effort required to make a program work. 

The City of Los Angeles provides an impressive 

example of an effective program to reduce landslide damages. Prior to 1952, controls on hillside 

grading and development in Los Angeles were 

very limited. In 1952, following severely damaging winter storms, a grading code was adopted 

that improved procedures for safe development of 

hillsides. The grading regulations were revised in 

1962 to provide a more restrictive code and to 

specify responsibility for geologic and engineering participation in design, construction, and 

final inspection and certification of the adequacy 

of a grading project. The procedures and controls 

received a stern test with the winter storms of 

1968-69. After the extensive flooding and landsliding, the Los Angeles Department of Building 

and Safety examined the damage to sites relative 

to when the site was developed and what grading 

4 

regulations were in effect at the tin~e of development. During the storms of 1968-r9, for a comparable number of sites, the dan1age to sites 

developed before 1952 was near1y 50 times 

greater than that to those developed between 

1963 and 1969 (Slosson, 1969). 

The urban areas studied in this report have all 

undertaken some form of action designed to 

reduce landslide damages. Several local and county governments in the San Francisco Bay region 

have adopted planning devices and grading 

regulations. Allegheny County, Pa., established a 

Geotechnical Center in the Departrr~nt of Works 

that maintains a technical data bank, recommends sources of assistance to individuals and 

organizations with problems, provides for public 

education about hazards, and condu~ts a data exchange with public agencies and conqulting firms. 

Cincinnati, Ohio, has adopted a C'lt-and-fill ordinance similar to the grading regulations in Los 

Angeles. 

Other communities with landslide problems 

generally have not adopted loss-reduction programs. They are apparently unaware of the 

magnitude of landslide losses or the potential for 

loss mitigation, partly because of a paucity of 

economic studies both locally and nationally. 

Major landslide disasters receive mr~h attention, 

but the day-to-day accumulation of landslide 

events results in surprisingly larg,; losses that 

receive little attention. 

LANDSLIDES DEFINED 

Landslides are downward and outward movements of slope-forming materials composed of 

natural rock, soils, artificial fills, or combinations 

thereof. Landslides can be classified in many different ways-by manner of moven1ent, type of 

materials, or age. But, for the purr0se of determining costs of damage caused by htndslides, no 

differentiation was made here. Scme agencies 

reporting landslide damage use the term 

"slipout" to describe an area in whiclt a section of 

a road has moved downward or th~ underlying 

material has "slipped out" from unier the road. 

Slipouts are included as landslides. 

LANDSLIDE DAMAGE 

Landslides commonly are considered to be only 

a local or a California problem. Ne~ther is true. 
Although single landslides may appear as 

isolated events both in time and place, the aggregate sum of individual landslides involves surprisingly large areas of land. In a nationwide 

study of the distribution of failed hill slopes and 

of materials susceptible to failure, Radbruch-Hall 

and others (1976) found significant problems in 

nearly every State. Colton and others (1976) 

mapped areas of previously failed slopes in Colorado and found that about 8 percent of the area of 

that State is underlain by landslide deposits. 

Similarly, in this report, we show that annual per 

capita1 damages in some other parts of the country are probably larger than those in some of the 

more landslide-prone areas in California. Landslides, in contrast to some other natural 

disasters, may have longer lasting damage that 

may, in fact, render land unsuitable for an intended use. Landslides can damage most types of 

manmade structures and have been reported to 

have damaged buildings, roads, transportation 

and communication facilities, utility installations, pipelines, reservoirs, irrigation ditches, and 

canals, as well as lots, parks, cultivated fields, 

pasture, and timberland. Some landslides may involve no out-of-pocket expense for damage, but 

may require an expenditure of the property 

owner's time and effort, such as picking up debris 

or cleaning or realining an irrigation ditch. Other 

landslides may cause damage in the millions of 

dollars and perhaps loss of life. Loss of life from 

landslides in the United States averages about 25 

persons annually (Krohn and Slosson, 1976). If 

deaths caused by collapse of trenches and other 

excavations are included, the annual total is between 100 and 150 persons. 

Damages from landslides vary greatly from 

area to area and, as smaller and smaller parcels of 

land are examined, damage is found to vary from 

neighborhood to neighborhood, block to block, 

street to street, and lot to lot. This pattern is 

roughly analogous to that for earthquakes, which 

produce similar variations in damage. In both 

cases, damage differences are due to several 

1 Reducing the damage costs to a common figure is desirable so that crude comparisons of damage can be made for different areas. In this report, per capita costs 

of damage are obtained by dividing the total annual cost of damage by the population of the area studied. In doing this, we knowingly introduce some distortions in 

the data. For example, per capita costs include not only costs borne by the inhabitants of a given city or county, but also public costs shared by inhabitants of 

higher and larger government entities ~State and Federal). Also, the costs within a 

study area are not evenly distributed. Private property owners with landslide 

problems carry the largest expense and the only truly distributed costs are public 

funds that are entirely generated within the study area. 

5 

natural and manmade conditions including 

method and materials of construction, ty"Je and 

condition of rock and soil, and steepness of 

slopes. 

It is possible to separate some of the causal factors that contribute to differences in landslide 

potential, evaluate their significance, ard produce useful maps that show where lanislides 

have occurred in the past and that shov· areas 

having different relative potential for land sliding 

in the future. Newman and others (1978) found 

that a composite map which combined stE:epness 

of slope, geological materials, and locatjons of 

past landsliding was sufficient to separate areas 

according to potential for future landsliding. 

Such a map readily identifies those areas that require more investigation or protection through 

land-use strategies designed to insure that. future 

use is compatible with the risk of landsliding. The 

characteristics of the different special-r~upose 

maps for landslide studies have been dir~ussed 

by Fleming and others (1979). 

Landslides are also a secondary effect cf other 

natural events and, as a result, the damage 

caused by landslides is often attributed to other 

natural disasters which trigger them. For example, it has been estimated that 65 percent of the 

damage of the Alaskan earthquake of 19~4 was 

caused by ground failure (Youd, 197r). The 

damage and deaths in central Virginia in 1969 are 

commonly associated with Hurricane Camille, 

but most of the nearly 150 people killed at that 

time were caught in rapidly moving debris avalanches triggered by the high-intensity rainfall 

(Williams and Guy, 1973). 

CATEGORIES OF DAMAGE COSTS 

Costs of damage due to landslides have often 

been classified as being direct or indirect, without 

either term being defined. Probably no definitions, unless they are complex, will provide for a 

clearcut assignment of every cost into on~ or the 

other of these categories. For the purpose of this 

report, a direct cost is defined as follows: the cost 

of physical damage and (or) related restoration 

costs to structures and land within the boundaries of the responsible landslide. All oth~r costs 

are indirect. 

The greatest value of separating direct and indirect costs may be to help insure that ell costs 

related to landslides are identified. The following 
lists, although incomplete, are intended to suggest the types of expenses in each category. 

Direct costs include destruction or damage to 

structures and other improvements, loss or 

damage to land, and (or) reestablishment of structures, other improvements, and land as nearly as 

possible to the same condition and degree of 

usefulness as prior to the landslide. 

Indirect costs include the following: relocation 

of buildings and roadways, measures to prevent 

or mitigate additional landslide damage, secondary physical effects such as flooding and 

adverse effects on water quality in streams and irrigation facilities, measures to prevent secondary 

effects, decrease in agricultural or industrial production, decrease in market value of affected 

properties, tax loss due to decrease in appraised 

value, and measures to protect health and safety 

of the public. Indirect costs can also include time 

lost from work and the associated effects of 

decreased earnings: the loss of purchase power 

which is passed on through the economy, possible 

foreclosure of mortgages and other loans, depletion of savings accounts, and lack of funds for insurance or investment plans. Obviously, many of 

these costs are seldom if ever determined, and 

damage assessments tend to be conservatively 

low. 

Perhaps the taxpayer and officials of involved 

agencies are more concerned with who pays the 

bill than with whether the cost is directly or indirectly attributable to a landslide. For that 

reason, costs compiled in this study are reported 

in two main categories: public and private. Public 

costs are dollars spent or lost by local, county, 

State, or Federal governmental agencies; these 

costs are ultimately paid by the taxpayer. Private 

costs are expenses to individuals and nonpublic 

groups, such as publicly owned utility companies, water districts, sanitation districts, communication companies, and businesses. Many of 

the private costs are probably passed on to 

clients and may be distributed to a large part of 

the public. 

Public costs are mainly expenditures for repairing, restoring, or relocating roads. These include 

expenses readily attributed to specific large landslides and an educated guess for smaller landslides that are included in budgets for routine 

road maintenance. Lesser expenses resulting 

from damage to sewerlines, storm drains, street 

lighting, sidewalks, and other publicly owned 

6 

facilities should also be included in cost compilations. In some instances, public agen~ies must obtain title to privately owned land in order to take 

measures to further protect property or to repair 

existing landslides. For example, in Daly City, 

Calif., title was obtained by the city for nine 

homes and the land damaged by lRndsliding in 

1969. In addition to the procurement cost, continuing minor costs are incurred by the city for 

erosion control and weed abatement. 

When possible, it may be more e~onomical to 

obtain title to property and have it vacated than 

to attempt to maintain access and services that 

are continually disrupted by an active landslide. 

However, tax revenue is lost when land is 

transferred from private to public ownership. 

Revenue loss also results from the d~valuation of 

private property because of landslide damage. 

Although these losses are substantial, to our 

knowledge no attempt has been mad<:'! to estimate 

their value in tax revenue because assigning an 

amount would be too speculative to b<:'! of use. Additional public cost includes emergency expenses 

such as salaries to firemen, policeme'l, and others 

responsible for protecting public heF lth and safety; but because records of these expenses are 

seldom available, the costs are not included in 

this report. 

Private costs are mainly the loss of real estate 

value and possessions, and the cost cf any repairs 

that are required because of lands~ide damage. 

Possessions can be replaced and inprovements 

undertaken if an individual is financi~lly able, but 

property may become unusable. In addition to 

the direct costs of repairs, real and p~~rsonal property that has been damaged by a landslide is 

often depreciated in value. Reapprairal by the tax 

assessor's office, which indicates a dE'~rease in the 

fair market value of property due to ~·nch damage, 

represents a loss to the property owner. Property 

adjacent to a landslide may also be depreciated, 

even though it has received no physical damage. 

Other private costs may include legal fees, consultant services, moving expenses, cleaning fees, 

and perhaps intangible social and f'i1ychological 

costs. 

Loss in the private sector can affe~t the public 

sector, and vice versa. When a busin ~ss is severely damaged, a loss occurs in the area's economy. 

This may be limited to a reduction in employee 

spending due to lost wages. If a plant is out of 

production for an extended period of time, it can 
result in a shortage of products and a reduced demand for supplies, both of which affect employees 

of undamaged businesses. Decreased production 

can also cause a loss in tax revenue and a decrease 

in utility use. Loss of these revenues for fixedcost services must then be spread among remaining users. 

Some costs cannot be classified as public or 

private; and others, though recognized to exist, 

cannot be estimated at present. The first are 

classified as "miscellaneous," and the second as 

''undetermined.'' 

Whenever feasible, it is advisable to assign 

costs of landslide damage as closely as possible to 

the segment of the economy in which the funds 

originate and minimize use of the category of 

miscellaneous costs. With adequate data, it 

should be possible to accurately place costs to the 

Federal government, State, county, township or 

city. However, this is not as simple as it seems. 

For example, total costs for repair of a city, county, State, or Federal highway are commonly the 

sum of support from two or more levels of government. If a detailed breakdown of costs is to be obtained, the sources and amounts of funds must be 

identified, as well as costs incurred by the agency 

that actually spends the money. 

Miscellaneous costs are those that cannot be 

assigned to the public or private sector. Ideally, 

these would include only costs for which the 

amount of damage is known but responsibility is 

disputed, in addition to the litigation costs between the public and private parties. Litigation 

costs are common but difficult to determine 

because of reluctance to release information. 

Available data indicate that the expense of civil 

suits can quickly exceed the amount of the 

original damage. The amount of awards in civil 

suits and whether they will be borne by the public 

or private sector may not be known until years 

after the damage occurs. 

Miscellaneous costs in the study by Taylor and 

Brabb (1972) of costs of landslide damage in the 

nine-county San Francisco Bay region in 1968-69 

amounted to nearly 25 percent of the total. Included were costs to the Federal government, 

cities, and publicly owned utilities, as well as 

litigation costs and costs where responsibility 

was disputed. In the estimate of damages for the 

same region in 1972-73 (Taylor and others, 1975), 

no miscellaneous costs were reported. Costs to 

cities were grouped with public costs, and costs 

7 

to publicly owned utilities were treated as private 

costs. 

Undetermined costs include, for example, the 

loss caused by landslides occurring directly into a 

reservoir or in the tributaries of its watershed. 

Such landslides contribute to siltation, which will 

reduce the reservoir's holding capacity. Although 

the dollar value of the lost storage is available, 

data on how much is due to landslides are not. 

Damages from landsliding that occur in conjunction with an earthquake or tropical storn also 

may not be separately identified. An exanple of 

an undetermined cost in the San Francisco Bay 

region was a proposed $10 million road project 

necessitated by a continuing landslide problem. 

This item was not included in the San Francisco 

Bay region estimate of costs, because relocation 

of the road was only planned but not furrfed at 

the time of the study. Construction would include 

modernization and an increase in the nurnber of 

traffic lanes, so the cost of the project would have 

to be discounted to a lower loss figure. 

METHOD OF OBTAINING COST INFORMATION 

The first step in obtaining cost information was 

to define the geographical limits of the ar€f.l to be 

examined. For the study areas described in this 

report, the urban areas are bounded by county 

lines, and the rural area is partly within a national 

forest and partly within city limits. The next step 

was to obtain background information on the 

types of landslides, their abundance and distribution, and some of the notable landslide events in 

each area. The first personal contact was made 

with geologists and engineers in Federal and 

State geological agencies who either were working or had worked in the area. In addition to providing specific information on landslide~·, these 

contacts were helpful in providing the nemes of 

knowledgeable persons in outside agenc~es and 

organizations. N ewsclippings maintained in 

scrapbooks, clipping services, and newspaper 

libraries were used to obtain partial datP and a 

list of potential contacts. The preliminary contacts with geologists and engineers served two 

purposes: they identified individuals and organizations that might have information on costs of 

landslide damage and they informed other.~ that a 

comprehensive study was underway. 

The next step was to interview agency personnel who might have data on landslide costs. If the 
appropriate individual within an agency was identified from the background study, initial contact 

was made with that person. Otherwise the head of 

the agency was contacted, because that official 

either had knowledge of, and access to, the information or could delegate the request to the appropriate individual and approve release of data. 

In most cases only one individual per agency was 

interviewed, and thus the information obtained 

may or may not be complete or even representative of the agency as a whole. 

Knowing the name of the person within an 

agency or organization to whom a request should 

be directed facilitated the work. When going from 

one governmental unit to another, it is helpful to 

obtain from a person in the first unit the name of 

someone working in a similar capacity in another 

agency. This also facilitated the study in another 

way, for when the new contacts found that others 

in similar positions were contributing information, they were more apt to cooperate. 

In the interest of impartiality, estimates of 

costs should be made by the agencies that contribute the data. If experience indicates that an 

estimate does not seem reasonable, an additional 

opinion can be sought from another official in the 

agency, but the estimate should be theirs. 

Requested information may be provided by 

written or oral communication, or by copies of official records. When no records are maintained, 

the written communication is preferred from the 

standpoint of documentation; however, oral information is more common. When given orally, costs 

are apt to be in a range of amounts rather than 

specific figures. Attempts to arrive at a more 

precise cost may result in settling for the figure 

at the low end of the range or for the median 

amount. Either of these procedures probably 

results in a conservative cost estimate. 

It should be recognized that the need for information on landslides is a new concept to most 

agencies, which usually do not maintain records 

useful for this purpose. As the need to be more 

aware of landslide problems becomes more widely 

accepted, we hope that losses and cost data will 

be more complete and accurate and can be obtained more easily. 

SOURCES OF COST INFORMATION 

Table 1 lists the public agencies and private 

sources in the San Francisco Bay region that con8 

TABLE I.-Public and private sources of data relating to 

the costs of landslides in the San Francisco Bay region 

Public Sources: 

Advanced Planning--------

Agricultural Commission 

Assessor's Office--------

Building Inspector-------

Local 

Chamber of Commerce------ X 

City Manager------------- X 

Civil Defense------------

Community Developers----- X 

Corps of Engineers-------

Department of Sanitation 

Department of Survey----- X 

and Mapping. 

Department of------------

Transportation. 

Design Office------------

Disaster Office----------

Division of Mines and----

Geology. 

Educational institutions X 

Emergency Services-------

Engineers---------------- X 

Farm Advisor-------------

Fire Department---------- X 

Fish and Game Department 

Flood Control District---

Forest Service-----------

Irrigation District------

Land D-evelopment---------

National Guard-----------

National Weather Service 

Parks and Recreation----- X 

Planning Commission------ X 

Public Information-------

Off ice. 

Public Works Department X 

Roads Department--------- X 

Seismic Safety-----------

Small Business-----------

Administration. 

Soil Conservation--------

Service. 

State Senator's Office---

Storm Damage Coordinator 

U.S. Geological Survey---

Utility departments------ X 

(gas, electric, water). 

Private Sources: 

C:...,.mmunication cvroranies 

Consulting engineers-----

and geologists. 

Gas and electric---------

companies. 

Homeowners---------------

Insurance companies------

Land developers----------

Private businesses-------

Real estate agents-------

Sanitation districts-----

Water companies----------

Governmental level 

County State Federal 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X--

X 

X X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

tributed information and indicates the level of 

government at which each public agency operates. Sources of information for the other examples in this report are listed in tb e discussion 

of damage costs for the particular area. Although 

these lists reflect our sources for the2e particular 

examples and we recognize that sour~es will vary 

froni region to region, nevertheless, ,~re hope that 
~ 

STATE OF CALIFORNIA 

DEPARTMENT OF FINANCE 

APPLICATION FOR STATE AID 

UNDER THE EMERGENCY FLOOD RELIEF LAW 

Section<, 54150-54164 of Government Code 

LIST OF STORM AND FLOOD DAMAGE 

Local Agency Contra Costa County 

(a) (b) (c) 

Item No. Description and Location of Facility Description of Damage & Repairs 

6 FAS 794, San Pablo Dam Road, 2.2 miles Major slip-out encroaching into shoulder, north of Wildcat Canyon Road, at "Sta. 235" progressing toward traveled way. StabiRoad 0961 

lize and/or reconstruct slope, install 

subdrainage, move road, if necessary. 

7 FAS 794, San Pablo Dam Road, 2.1 miles Major slip-out breaking across AC berm at 

north of Wildcat Canyon Road, at "Sta. 226" edge of pavement. Install subdrainage, 

replace cross culvert, cut back hillside 

Road 0961 and grade for road relocation. 

8 FAS 794 Camino Pablo, Orinda, opposite Slip-out and creek erosion resulting in 

Ard i 11 a Road roadway settlement. Stabilize roadbank, 

install subdrainage, construct culvert 

Road 0961 H.O. 6265 for creek if necessary. 

9 FAS 794, Moraga Way, Orinda, at northerly Slip-out of shoulder due to creek erosion. 

intersection with Ivy Drive Install culvert in creek, reconstruct 

roadbank over it. 

Road 0961 W.O. 6469 

Total Estimated Approximate 

Cost Expenditure 

To Date 

$200,000 -0-

$350,000 -0-

$ 82,400 $ 3,500 

$ 14,000 $ 1 ,000 

j 

10 FAS 1019 Camino Tassajara, Danville, at Slip-out of shoulder and damaged traveled $ 16,200 $ 5oo I 

M.P. 5.15 way due to cre€k erosion. Fill eroded 

bank with riprap, reconstruct roadbank, 

Road 4721 W.O. 6474 repair pavement. 

11 FAS 1019, Camino Tassajara, Danville, at Slide blocking part of one lane. Remove $ 3,140 

M.P. 8.25 slide, flatten cut slope. 

Road 4721 W.O. 6426 

--

(a) Care should be exercised in designating items since covering agreement will correspond if State aid is granted. Cost must be segregated accordingly in local 

agency accounting records. 

(b) If application covers damage to roads, streets and bridges, include F AS or County route designations. 

(c) If application covers damage to roads, streets and bridges, include net length. 

$ 500 

FIGURE 1.-Extract from an application for State disaster relief from Contra Costa County, Calif., listing landslide location, description of 

damage, and total estimated cost of repairs. What the "total" cost includes is not stated, and experience indicates that it may not represent 

the complete cost of damage including such items as emergency services and engineering costs. 

I 
Form Approved 

OMB No. 063-R1424 

U.S. DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT 3. DECLARATION NO. 

DAMAGE SURVEY REPORT FDAA 5/16/73 

FEDERAL DISASTER ASSISTANCE ADMINISTRATION 4. INSPECTION D/\TE 

(See instntctions on reverse' o.f last cnpy) 1:./1 /7'l 

1. TO ' REGION _Jl_ FEDERAL DISASTER ASSISTANCE ADMINISTRATION (FDAAI ) 

5. WO'lK A~<!o'MP'tTSHED BY 

ijl GOI\ITRACT 

2. APPLICANT (State Agency, Cou11ty, City, etc.) 1PAN0_ 0 FORCL ACCOUNT I Countv of Hawaii 1 P-1927 7. WORK CATEGORY ("X" Applicable Bo:IC) liTEM NO. 6. PERCENTAGE OF WORtf 

0 Etlt'Er.GFNC'! I COMPLETED TO DATE 

IIJ PERMANENT OA DB ~c Do DE OF OG OH 01 I 22 90 "' 8. DAMAGED FACILITIES (Location, identi{icatioilqnd description_) 

Mamalahoa Highway at Kolekole Gulch, Honokaa side of Kolekole Park. 28' roa-iway with 16' A.C. pavement and C.R.M. wall at down hi 11 side. 

9. DESCRIPTION OF DAMAGE 

C.R .• M. wall badly ruptur~d but still intact. Earth cracks and pavement cracks 

110' long parallel to the road at downhill side of road. 

10. SCOPE OF PROPO:iED WORK 

Relocate road closer to uphill side by cutting back at a 1 :2 slope and 

surfacing the widened area. Patch all cracks and C. R . M. wa 11 . Provide stripin, and delineators. 

11. f;STIMATED COST OF PROPOSED WORK 

QUANTITY UNIT MATERIAL AND/OR DESCRIPTION UNIT PRICE COST (dolliJrr) (a) (b) ·(c) (d) (e) 

696 c._v. Unclassified Excavation 20.00 13.920.00 

95 C.V Subbas~ 15 _no 1 .4?5 nn 

32 C .V Bas!=! Course __2_5_. no snn_no 

33 Ton~ 211 A C for wid~nina 40 nn 1 ~?n nn 

84 Tons 1-1/2" A C for n .1:! • . ina 32 no 2 6R8 no 

16 Each RM-1 Delineators 75 00 1.200.00 

1 Each R-7-1 "No Parkina At Anv Time" sian 75 00 75.00 

L /S Strinino 900 on qnn nn 

I /C:.. R,::~n;drino Exi~tino r. R M w~u flOO_ on 1 nnn nn 

Construction ~ub Total 23,328.00 

Survevina 150 00 

Enaineerina 250.00 

Drafti no and C ms .T IL inn F'noin~~rino ""n nn· 12. EXISTING INSURANCE (Type) :AMOUNT T.OTAL Nnt " I t4,378.00 ~ 1$ 

13. RECOMMENDATION BY FEDERAL INSPECTOR (Signature, Agenc-y, date) El~il)lu ATTACHMENTS 

O--rEs 0 NO 

14. CONCURRENCE IN REPORT BY STATE INSPECTOR (Signature, Age11cy, date) AT"i'ACt<MENTS 

DYES 0 NO 

15. CONCURRENCE IN REPORT BY LOCAL REP~CC-SENTATIVE (Signat:tre, Agency, date} ATTACHMENTS 

Ov·£s 0No 

16. FEDERAL. REVIEW (Signature, Agency, date) l FDAA REV•Ew (Initials and date} 

_j_ 

HUD· 484 (9-74' REPLACES OEP FORM 164 WHICH IS OBSOLETE COPY 1 - FINAt.fCIAL MANAGEMENT SHEET __ OF ___ SHEETS 

FIGURE 2.-Application for Federal disaster relief from the County of Hawaii, Hawaii. In addition to providing location and 

description, this document itemizes estimated costs of construction and engineering that are included in the total. 

10 
FIGURE 3.-View of a landslide scarp adjacent to a home in Oakland, Calif., illustrating some of the problems of assigning 

dollar values to landslide damage. The landslide occurred during the winter of 1968-69 and destroyed several 

houses. Although access to this house was impaired and resale value reduced, the house remained habitable. 

these lists will serve as a starting place to identify organizations that otherwise might be 

overlooked. 

Names of agencies fulfilling the same function 

may vary from place to place. For example, what 

is known as "Design Office" in one county may 

be called "Public Works" in another. In addition, 

several offices may be included under any one 

heading and so, for example, a Road Division may 

be divided into grading, materials, design 

engineering, construction engineering, maintenance, accounting, and perhaps other units. 

Each may have cost figures but may not be aware 

of information in other offices. 

Probably the most extensive and accessible 

records, when they exist, are agency applications 

for State or Federal disaster relief. Such applications include location, type of damage, and 

11 

estimated restoration costs. Even these records 

vary in completeness (figs. 1, 2), however, and do 

not include administrative staff time. Almost 

equally useful are records in any agency where a 

separate file is kept of information relating to 

landslides. If the agency has one person responsible for maintaining such data and being aware 

of all work on landslides, relatively complete information can be obtained. 

Although an agency may maintain files of work 

orders or job tickets for damage repair, they may 

not be indexed by type of occurrence. This 

necessitates an examination of all work orders for 

the time period in question in order to locate data 

pertaining to landslides. The same process may 

be necessary with contracts or requisitions when 

an agency has used outside contractors or suppliers in conjunction with repair of damage. 
Agencies that do not categorize road work by 

type of damage may provide a radio log that 

gives an indication of the type of occurrence, its 

location, and date. By knowing the location and 

date, further search of job files may reveal cost 

figures filed under those headings. Commonly, 

cost estimates must be based on the memory or 

field notes of employees, and it may be helpful to 

them to mention specific landslides in the area to 

prompt recall. 

In some agencies the only pertinent data may 

be a total figure from the yearly report or budget 

in which a specific amount is allotted for landslide 

problems. It may or may not include costs of 

emergency services, restoration, maintenance, inspection, fees for outside services, and related 

staff time. 

PROBLEMS ENCOUNTERED 

The major problems encountered in obtaining 

cost information are lack of, or incomplete, 

records; difficulty experienced by sources in 

retrieving information; unwillingness of sources 

to attempt to locate data; confidentiality of data; 

and data that do not separate damage from other 

costs. For various reasons some sources simply 

refuse to release information, leading to the conclusion that documented costs are minimum 

figures. 

Numerous additional problems are encoun~ 

tered. Different periods of data recording (fiscal 

year, calendar year, seasonal year) are used by 

various contributing agencies. Litigation, 

whether threatened or in progress, results in a 

natural reluctance to release information. 

Difficult decisions may be required pertaining 

to what part of a total cost is attributable to landsliding (fig. 3). In the studies reported here, when 

interpretation of cost data was necessary or 

duplications of costs could exist, a low or conservative estimate was used. For example, the 

SBA (Small Business Administration) loans for 

landslide losses indicated private damages in Cincinnati and Delhi Township, Ohio, during 1973 of 

$1.2 million. This figure was larger than the 

reported costs provided by the consulting firms. 

The data from the consultants for those areas 

during 1973 were dropped because some duplication of costs was probably involved. 

Establishing a yearly cost for a landslide event 

is a problem if its movement is a chronic, contin12 

uing, or yearly process, or if the landslide occurs 1 

year but no funds are available for repair until a 

later year. The first instance might require taking 

one-tenth of the amount spent over a 10-year 

period, while the other might necessitate taking 

one-tenth of the amount spent in 1 year to repair 

damage during the preceding 10 years. 

Probably the greatest shortcoming in recordkeeping is that few agencies maintain a centralized record of the total amount of money ,or time 

expended on any specific landslide problem, or on 

landslides in general. 

The net effect of problems associated with the 

data gathering is that reported costs of landslide 

damages tend to be less than those actually incurred. Investigations following preliminary published reports of landslide damage in the San 

Francisco Bay region (for example, Taylor and 

Brabb, 1972) show that, as further studies are 

made, additional costs can be identified. Assumptions must be made in order to compare costs 

from county to county and from year to year. Until more complete data are available, however, 

these costs provide a conservative estimate of the 

total cost of landslide damage. 

REEXAMINATION OF COSTS OF LANDSLIDE 

DAMAGE IN THE SAN FRANCISCO BAY REGION 

(1968-69) 

The winter storms of 1968-69 in the ninecounty San Francisco Bay region produced an 

unusually large amount of landslide damage. In 

an attempt to determine direct and indirect costs 

of landslides to public and private interests, the 

U.S. Geological Survey undertook one of the first 

detailed studies of the cost of landsliding in so 

large a geographical area in the United States 

(Taylor and Brabb, 1972). Although the investigation followed the methodology described 

earlier, practically no guidelines existed at that 

time. Nevertheless, the study identified landslidedamage costs totaling about $25 million. In a 

followup study of damages that occurred in the 

same area during the winter of 1972-73, Taylor 

and others (1975) identified nearly $10 million in 

landslide damages. The second study revealed 

new sources of information and improved familiarity with record-keeping practices; as a· result, 

previously undetected costs in sources that had 

been examined were uncovered. The improved 

perspective on types of costs and locations of in-
TABLE 2.-Estimated costs of landslide damages in the 

nine-county San Francisco Bay region (1968-69) 

Source 

Public: 

State------------------

Coun t y-----------------

C it y-------------------

Tax loss---------------

Private: 

Initial survey 

(Taylor and 

Brabb, 1972) 

$ 4,996,000 

5. 177,000 

12,000 

Reexamination 

$ 7,000,000 

6,000,000 

4, 200,000 

Property depreciation-- 7,106,000 7,100,000 

Utilities-------------- 213,000 200,000 

Property damage-------- 1,983,000 12,000,000 2 C$25,800,000) 

Miscellaneous------------- ·--'5eJ.-, 9=0.:.J.7 •=00"'-0 -~5 ,~90~0,'-'-00~0 

Total---------------- $25,394,000 $32,400,000 ($56,200,000) 

1Assumes SBA loans duplicated or did not exceed cost of damage 

as determined from other sources. The estimate is conservative. 2Assumes costs of damage to private property were equal to 1.5 

times public costs. Ratio was determined from SBA data on loans 

provided during the winter of 1972-73. The estimate probably eKceeds 

actual costs of damages. 

formation led us to reexamine the sources and 

data for 1968-69. The data are summarized in 

table 2, which shows the results of the initial 

analysis and the reevaluation. 

In the initial survey (Taylor and Brabb, 1972), 

State expenses were reported to be about $5 

million for damage to highways. However, subsequent information indicates that amount should 

be about 40 percent greater (Robert M. Schroll, 

California Department of Transportation, oral 

commun., 1976). This is an 8 percent increase in 

the reported total of $25 million due to landslide 

damage for that single winter. Data as originally 

furnished did not include staff time and complete 

engineering costs. For similar reasons county 

expenditures previously reported, which were 

mainly for county roads, should be about 15 percent higher (Edward H. Meyer, Alameda County 

Public Works Department, oral commun., 1976) 

or an additional 3 percent of the total. A report 

covering the same area for the winter of 1972-73 

(Taylor and others, 1975) indicated that the costs 

to cities (about $1,195,000) were about 0.7 as 

great as those of the county (about $1,653,000). 

With a few exceptions, which would not materially change the results, city costs were not included 

in the report covering 1968-69.2 Revised county 

costs for the period of 1968-69 are $6,000,000, 

and if city costs are 0.7 as great it would add 

2

That city costs are substantial and nearly as large as county costs was not 

learned until the costs of damage were compiled for the winter of 1972-73 (Taylor 

and others, 1975). During the initial survey, city costs were thought to be relatively insignificant and to not justify the time required to document them. 

13 

about $4,200,000 or 17 percent to the total initially reported for the 1968-69 period. 

Information not previously available suggests 

that costs initially assigned to the private sector 

could have been greatly understated. In Marin 

County, the SBA gave assistance to thos€. suffering storm damage during the winters of 1968-69 

and 1972-73. Data have been made available for 

only the 1972-73 period but will serve as a basis 

for better estimates of private costs. The f'BA interviewed 1,967 prospective applicants fc..- loans 

to cover expenses due to flooding and landslide 

damage. Ninety percent of permanent damage 

was due to landsliding (Herbert Wimmer, Marin 

County Building Inspector, written co'llmun., 

1976), and SBA data herein quoted are reduced to 

this amount. Approval was given for 691 home 

loans amounting to about $2,300,000 and 65 

business loans for about $900,000; this is an 

average of $3,000 per home loan, with business 

loans averaging $14,000 (Robert Belloni, SBA, 

oral commun., 1976). 

Of the 952 persons interviewed but no~ applying, SBA estimated that 85 percent or 809 had 

damage that would have been covered h!:ld they 

been willing to go through the required procedure, or if the request exceeded $6,000, to 

secure the loan application with real pror~rty. If 

these prospective applicants had only ab0ut onethird the average ~orne damage ($1,000), it would 

be an additional $800,000. 

These three items-home loans, businers loans, 

and potential loans-amount to $4,000,000 

which, to avoid duplication, replar~s the 

$1,094,000 already reported as private expense. 

The costs, which are for only one county (Marin) 

of the nine counties in the San Francisco Bay 

region, increase the estimate of cost of c.::tmages 

for 1972-73 of Taylor and others (1975) b~r 30 percent. If costs of damage to private property as 

revealed by SBA loans in the other eight counties 

were in the same proportion to those initially 

compiled in Marin County, the estimate of costs 

of private damages is $8,700,000 larger than 

reported (Taylor and others, 1975) and the total 

cost of damages for 1972-73 is about 

$18,400,000. This revised value has been based on 

some assumptions that may not be cons~rvative 

and may overestimate the cost of damq_ges for 

1972-73. 

SBA data on loans to repair costs of l!:lndslide 

damage for the winter of 1968-69 ~·~re not 
available, and assumptions are necessary to 

revise the estimate of costs to the private sector. 

In table 2, two values are provided: The lower 

value assumes that SBA loans were equal to or 

less than the estimate of private costs obtained 

from other sources, in which case the SBA value 

would be discarded because of possible duplications. The higher estimate was obtained by comparing ratios of public to private costs for 

1968-69 and 1972-73. Costs for damage to 

private property in Marin County in 1972-73 

were about 1.5 times as large as the reported 

public costs of about $2,000,000 (Taylor and 

others, 1975). In 1968-69, the estimated public 

costs (as revised) for the nine-county region were 

approximately $17,200,000. Assuming that the 

1.5 ratio of private property damage to public 

costs in Marin County in 1972-73 is approximately valid for the entire nine-county region for 

the winter of 1968-69, the revised costs of 

damage to private property in 1968-69 are about 

$25,800,000. 

These increases in cost estimates for State 

highways, county roads, city expenses, and 

damage to private property indicate that the 

total of $25,394,000 initially recorded for 

1968-69 was understated and should be increased 

at least by an additional $7,000,000 and perhaps 

by as much as $30,800,000. The total cost of 

damages for the nine-county San Francisco Bay 

region for the winter of 1968-69 is probably between $33,200,000 and $56,200,000. 

The upper value ($56,200,000) is probably 

unrealistically large. Although the total amount 

of rainfall and number of landslides were about 

the same in 1972-73 as in 1968-69, the cost of 

damage was only about half as much in 1972-73 

and more than 30 percent of it was in Marin County. In 1968-69, only about 4percent of the cost of 

damage was in Marin County. The extrapolation 

of cost-of-damage data from Marin County in 

1972-73 to all nine counties of the Bay region in 

1968-69 is speculative but serves to place an upper limit on the costs. The lower value of 

$33,200,000 is a conservative estimate. The procedure discards information that could be 

duplicated and uses a low value if interpretation 

or apportionment of costs is necessary. 

The incidence of landsliding in the San Francisco Bay region is related to patterns, intensity, 

and total amount of rainfall. In some years, 

numerous landslides occur and in others, practically none. To obtain an annual per capita 

estimate of costs of damage for the S·::m Francisco 

Bay region, it is necessary to determine the recurrence of landslide-causing storms and to apportion the costs over years of little or no landslide 

activity. During the past 30 years in southern 

California, damaging landslides have been triggered about every 4 years. Nilsen and others 

(1976) estimated that mean aniJual rainfall 

similar to that in 1968-69 and 1972-73 has occurred in about 4 out of every 10 yearr~ in the Bay 

region during about the past centur~'· The total 

estimated costs of damages for 1968-69 and 

1972-73 are assumed to represent a 10-year 

period of landslide damage (probably a conservative estimate). Taking the m~~an of the 

estimated costs of damage for 1968-69 and 

1972-73, adding them, and dividin!l~ by ten produces an estimate of the average annual costs of 

about $5,900,000. Dividing this by the 4,600,000 

population of the nine Bay region CC1lnties gives 

an estimate of annual per capita cost.s of damage 

of about $1.30. This estimate ignores litigation 

and repair costs accrued in years other than the 

years when the landslides occurred and costs of 

damage were compiled. 

COSTS OF LANDSLIDE DAMAGE IN ALLEGHENY 

COUNTY I PENNSYLVANIA (19T1-76} 

Costs of landslide damage have been documented for several areas in the Wertern United 

States, but few studies have been c'>mpleted of 

losses in the East. William R. Ad::tms, Jr., of 

the Allegheny County Geotechnical Center, conducted a preliminary study of the costs of landslide losses in Allegheny County. His study 

revealed that large losses occur annually and that 

a more complete accounting of landsl~ile damages 

could be obtained through interviews with some 

of the affected agencies and individuals. The 

assistance of Mr. Adams in providi"lg data and 

information on organizations is gratefully 

acknowledged. 

Allegheny County is a highly urbanized county 

in western Pennsylvania, and Pittsburgh is its 

principal city. The county has 1.6 million inhabitants within its 1886-km2 (7Z~-mi ) area. 

Landslides have been a continuing problem for 

many years (fig. 4). The areas susceptible to landsliding in Allegheny County have b~en mapped 

by Pomeroy and Davies (1975). 

14 
FIGURE 4.-Rockfall in Pittsburgh, Pa., that closed Parkway East on April27, 1978. Photo courtesy of William R. Adams, Jr. 

This is a summary of the estimated costs of 

landslide damage in Allegheny County for the 

7-year period of 1970-76. All costs are in terms of 

dollars expended during a given year, and no adjustments have been made for inflation. Information reported here was obtained from interviews 

conducted in Allegheny County during the week 

of August 8-12, 1977, from Mr. Adams, and with 

followup correspondence. Only a small percentage of all the potential sources of information was 

contacted. Undoubtedly a more comprehensive 

survey would reveal additional losses. Public 

sources that were contacted included Federal, 

State, county, and city agencies such as road 

departments, planning departments, environmental departments, and assessors; utility companies; sewage disposal agencies; and schools. In 

most organizations, only one individual was con15 

tacted. A listing of organizations that were 

contacted or that contributed information is in 

table 3. 

The principal problem in obtaining data on 

costs of damage from landslides in Allegheny 

County is the very large number of sources 

that might have information. Only the most obvious sources could be contacted in the time 

available. There are 129 municipalities in 

Allegheny County. Some of these have offices 

that maintain records of costs for repair of landslide damage; others contract such work through 

private consulting companies and may have an 

incomplete account of costs. At least 200 utility 

companies exist in the county (table 4); added to 

these are several railroads, various river transportation authorities, and numerous commercial concerns. Other organizations that might have infor-
TABLE 3.-Sources of information contacted on costs of landslide damage in Allegheny County, Pa. 

Source 

City of Pittsburgh: 

City Parks 

Department of Lands and 

Buildings. 

Department of Public Works 

District Permit Engineer 

Personal property Tax Office 

Pittsburgh Public School System 

Planning Department 

Police Department 

Statistical Information 

Water Department 

Allegheny County and 

Regional Off ices: 

Allegheny County Geotechnical 

Center. 

Allegheny County League of 

Municipalities. 

County Parks 

Intermediate Unit (schools) 

Police Disaster Office 

Public Works Planning and 

Development. 

Regional Parks 

Source 

Non-county agency: 

Allegheny County Sanitary 

Authority. 

Commonwealth of Pennsylvania: 

Bureau of Topographic and 

Geologic Survey. 

Department of Environmental 

Resources. 

Department of Transportation 

(PennDOT). 

National Guard 

Property Tax Assistance 

Bureau. 

Solid Waste Management 

State Forestry 

Water Quality 

Federal government: 

Corps of Engineers 

Soil Conservation Service 

Private: 

Consulting engineering and 

geology firms. 

Utility companies 

mation but were not contacted are the Allegheny 

County Assessor's Office, Southwest Pennsylvania Regional Planning Commission, Pennsylvania Department of Mine Subsidence, and 

various other county and city of Pittsburgh offices. Additional Federal and private costs might 

have been obtained, particularly for 1972, from 

the SBA and the Federal Disaster Assistance 

Administration. 

The willingness or ability to provide data 

varied from organization to organization. Some 

sources could give a fairly complete account of 

expenditures for landslide damage, whereas 

others could give only a yearly estimate. Some 

consultants were reluctant to release information 

out of concern for the confidentiality of their 

clients. 

Most of the costs data in this report are for the 

calendar years 1970-76. However, because so~e 

agencies use different recording periods-fiscal 

year or seasonal year-some costs may not have 

occurred in the calendar year to which they are 

ascribed. This discrepancy probably does not 

materially affect the total cost estimates. 

Two categories of costs are reported: public and 

private. Most of the public landslide costs is the 

direct expense of repairing and restoring roads. 

This includes expenses readily attributed to 

specific large landslides and an educated guess 

for smaller slides, as these costs are included 

within budgets for routine road maintenance artd 

repair. Public costs also include damage to 

municipally owned utilities and sidewalks and to 

16 

TABLE 4.-Types and number of utility companies in 

Allegheny County, Pa. 

[W. J. Adams, Jr., written commun., 1978) 

Type Number 

Telephone companies------------------------------------------ 8 

Gas companies------------------------------------------------ 11 

E lee t r ical companies----------------------------------------- 3 

Heating transmission companies------------------------------- 1 

Petroleum transmission companies----------------------------- 11 

Cable television companies----------------------------------- 15 

0 il companies------------------------------------------------ 30 

Water companies---------------------------------------------- 58 

Sewerage companies------------------------------------------- _jU_ 

To tal-------------------------------------------- 200 

other publicly owned facilities. Some public costs 

could not be classified as Federal, State, or county and were grouped as "municipal and other 

public funds.'' I terns under this heading include 

expenses jointly funded by several levels of 

government, expenses of schools and parks, and 

those for several landslides believed to have 

resulted in local expenses but for which documentation was incomplete. Private costs are expenses 

to individuals and nonpublic groups. 

Table 5 shows amounts attributed to both the 

public and private sectors for the years 1970-76. 

Damage repairs, including construction ' and 

maintenance costs, by the Department of Transportation are generally the highest single yearly 

expense. Several sources indicated that costs of 

preliminary design and engineering work and inspection, which are not routinely included in 

quoted construction costs, are almost 15 percent 

of the construction cost. This amount has been 

added to repair costs for each yearly total. Extensive Federal funds were expended in 1972 to 

repair landslide damage caused by Hurricane 

Agnes. 

Private costs for the 7-year period range from 

15 to 45 perc~nt of the yearly total. The 

15-percent figure is for 1972, when additional 

public monies were spent owing to Hurricane 

Agnes. The yearly average of private costs is 31 

percent of the total. Informati9n regarding 

private expenses was provided almost exclusively 

by seven private consulting engineering and 

geology firms. More extensive participation by 

other such firms would have resulted in a more 

complete account of costs and a higher yearly 

total. Note that the estimated costs of damages 

provided by consultants is the same amount for 

each of the years 1970-72. This is a result of all 

seven consulting firms estimating that the costs 

of landslide damages were the same or in the 

same range for those years. 
T ABLE 5.-Costs of damage due to landslides in Allegheny County, Pa. (1970-76) 

7- year Yea r ly Annual per 

Sour ce 1970 1971 1972 1973 1974 1975 1976 total avet:age capita cost 

Public: 

Federa l----------- $3 , 000 $3' 000 $903 , 000 $3 ' 000 $3, 000 $3 , 000 $3 , 000 $92 1, 000 $132,000 $0 . 08 

State------------- no data 3 19 , 000 1,801, 000 703 , 000 290 , 000 1 ,768 , 000 952,000 5 , 833,000 833,00C .52 

Count y------------ no da t a 10,000 122 , 000 10 ,000 20,000 2,000 2,000 166, 000 24, 000 . 0 1 

Mun icipal and 

other public 

f unds----------- 878 , 000 393 , 000 600 . 000 466 ,ooo 705. 000 793 ,000 450 , 000 4, 285 , 000 6 12 , 000 . 38 

Sub t ota l--- 88 1 ,000 725.000 3,426 , 000 1,182,000 1,0 18,000 2,566,000 1, 407,000 11 , 205 , 000 1,601,000 . 99 

Private------------- 582 . 000 582 , 000 582 , 000 621, 000 590 ,000 574 , 000 554 , 000 4 , 085,000 584,000 .36 

Total---- - - $1 , 463,000 $ 1 ' 307,000 $4,008,000 $1,803,000 $1 , 608,000 $3,140,000 $1,96 1, 000 $ 15, 290,000 $ 2,185 , 000 1 ($4,000,000) $ 1. 35 

($2.50) 

Percent of total 

that is private 40 45 15 34 37 18 28 27 27 ----------- 1Because only a few of t he more obvious sou r ces of cost s- of- damage i nformation were contac t ed, t he aut hor s t h ink t ha t the annua l cost 

exceeds $4 million. 

This study, limited in both time and in the 

number of sources contacted, indicates that an 

average of nearly $2.2 million per year is spent in 

Allegheny County owing to landslide damage. 

Studies of the San Francisco Bay region (Taylor 

and Brabb, 1972; Taylor and others, 1975; and 

this report) have shown that preliminary documentation of economic loss due to landslide 

damage may be less than half the actual total. 

This is likely true for Allegheny County, and 

landslide damage probably costs the public and 

private sectors there an average of at least $4 

million per year. 

If the $2.2 million figure is divided by Allegheny County's 1975 population of 1,605,016, the 

annual per capita cost of landslide damage is 

$1.35. Using the more realistic $4 million figure 

would raise this to $2.50 per capita per year. 

COSTS OF LANDSLIDE DAMAGE IN HAMIL TON 

COUNTY, OHIO (1973-78) 

Hamilton County, Ohio, and nearby counties in 

Ohio and Kentucky have experienced severe landslide problems in both public and private land. 

Landslides occur most commonly in colluvium 

developed on shales of the Kope Formation and in 

glacial deposits, principally till and lake clays. 

The types and physical setting of the landslides 

in the Hamilton County area have been described 

by Fleming (1975). Figure 5 shows a typical landslide problem involving several homes in the 

northern part of Cincinnati. The landslide, which 

is developing very slowly in glacial-lake clays, has 

produced obvious cracks in the house, sidewalk, 

and driveway. The small scarps and bumps in the 

17 

lawn could be easily overlooked as landslide 

features by an unsuspecting observer. 

FIGURE 5.-Cracks in a slowly developing landslide in glacial 

materials damaging this house and several others in a subdivision in Hamilton County, Ohio. Landslide problems in 

1973 in this same subdivision did not affect homes but 

necessitated expensive repairs. 

Local officials and the general public are 

working to reduce landslide damages. The City of 

Cincinnati enacted an excavation and fill ordinance in 1974, and the City Planning Department is regulating development through the use 

of zoning districts for hillside areas. The City of 

Cincinnati has also sponsored a project to identify and map slopes susceptible to landsliding. 

The Hamilton County Departments of Planning 

and Engineering have active programs to reduce 

landslide losses. Landslide events receive extensive coverage in the news media, and the public is 

being informed of the signs that a slope failure 
TABLE 6.-Sources of information on costs of landslide 

damage in Hamilton County, Ohio 

Source 

Cities, villages, and townships 

City of Cincinnati: 

Structures, Permits, and Highways, sections of Engineering 

Division. 

Highway Maintenance 

Planning Department 

Building, License, and Permit 

Office. 

Metro Sewage Disposal 

Water Works 

City Park Board 

City Public Utilities 

· City Public Library 

Regional Computer Center 

Hamilton County: 

Engineering Division 

Auditor's Office 

Real Estate Tax Office 

Planning Department 

Building Department 

Ohio: 

Department of Transportation 

Bureau of Employment 

Source 

Federal Government: 

SBA 

Federal Housing Administration 

Cincinnati Metro Housing 

Authority 

U.S. Department of Agriculture 

Soil Conservation Service 

Internal Revenue Service 

U.S. Geological Survey 

Private: 

Engineering Society of 

Cincinnati 

Cincinnati Institute 

Salvation Army 

Cincinnati Gas and Electric 

Cincinnati Bell 

N & W Railroad 

Conrail 

Chesapeake and Ohio Railroad 

"Cincinnati Enquirer" 

Private consulting firms 

may be occurring and of potential remedial 

techniques. 

Contact was made with 39 of the 50 municipalities within Hamilton County. Calls to the 

telephone numbers of 11 cities and townships 

were unanswered, but it is likely that data supplied by the Hamilton County Engineer's office 

include damages incurred by most of these 

municipalities. Other agencies that might have 

cost data were also contacted. Table 6 lists the 

organizations contacted. 

The local interest in landslide problems facilitated the collection of costs-of-damage information. Virtually everyone contacted gave freely of 

time and costs data. Although 38 cities, 12 townships, and a large unincorporated area compose 

the 1072-km2 (414-mi2)area, we believe that the 

survey of costs of damage is reasonably complete. 

Although the data are considered complete, an 

event that would have greatly increased damage 

figures was intentionally not included. A major 

landslide in Cincinnati in 1974 resulted in damage 

to a highway under construction and to several 

private structures. Some public and private funds 

have been expended for study, emergency services, and temporary repairs; and some of these 

costs may be included in our compilation. In 

1979, estimates for permanent repair of the landslide went upward from about $22 million and 

litigation is in process. Many interests are involved, including public agencies, private landowners, consultants, and attorneys; and it is like18 

ly that the landslide will be one of the most costly 

to date in the history of the United States. 

Because the landslide has not been repaired and 

the legal issues have not been resolved, the only 

costs associated with it included in this tabulation are relatively insignificant. 

The costs of landslide damage in Hamilton 

County, Ohio, for the years 1973-78 are summarized in table 7. Total damage costs for the 

6-year period are $30,990,000. The annual 

average cost of damage is $5,165,000 unadjusted 

for inflation. Dividing this figure by the population of Hamilton County (883,800 in 1977) produces an average annual cost per capita of about 

$5.80. 

PRELIMINARY ESTIMATE OF COSTS OF LANDSLIDE 

DAMAGE IN THE MANTI, UTAH, AREA (1974-76) 

BACKGROUND 

The city of Manti, with a population of about 

1,800, is situated near the geographic center of 

Utah. It is located on an alluvial fan at the mouth 

of Manti Canyon, which is about 14.5 km (9 mi) 

long from east to west and as much as 5 km (3 mi) 

wide (fig. 6). Most of the canyon slopes, particularly on the south side of Manti Creek, are 

characterized by hummocky topography and 

scars of past landslides. One of these old landslides, located within the Manti-La Sal National 

Forest and about 6.5 km (4 mi) from the city of 

Manti, was reactivated in the spring of 197 4 

(fig. 6). 

Reactivation of the landslide was triggered by a 

rock slide from the south rim of the canyon. The 

rock slide, mixed with abundant water from 

snowmelt, mobilized into a debris flow. Part of 

this debris flow came to rest on, and thus loaded, 

the upper portion of the old landslide. Cracks 

propagated downslope in the landslide mass, and 

a waterline supplying water and providing hydroelectric power for Manti was broken. During the 

first year, movement was confined to the upper 

two-thirds of the landslide. Movement rates locally exceeded 6 m (20ft) per day, and a total of 

more than 60 m (200 ft) of downslope displacement occurred. In mid-1975, cracks formed in the 

lower part of the landslide; by August 197 5 the 

active landslide, comprising perhaps 15 million 

m3 (20 million yd3

) of debris, was about 3.2 km (2 

mi) long and as mu~h as 0.8 km (0.5 mi) wide. Dif-
TABLE 7.-Costs of landslide damage in Hamilton County, Ohio (1973-78) 

6-year Yearly Annual per 

Source 1973 1974 1975 1976 1977 1978 total average capita cost 

Public: 

Cincinnati and other 

cities and townships $1,410,000 $560,000 $3,460,000 $1,000,000 $320,000 $400,000 $7,150,000 $1,192,000 $1.35 

Hamilton County------- 200,000 350,000 150,000 540,000 160,000 2,000,000 3,400,000 567,000 .64 

State----------------- no data no data 120,000 60,000 no data 580,000 760,000 126,000 .14 

Federal--------------- 40,000 2,310,000 2,400,000 1,640,000 1,760,000 120,000 8, 270,000 1,378,000 1.56 

Miscellaneous public-- no data 70,000 50,000 no data no data no data 120,000 20,000 .02 

Subtotal------- 1,650,000 3,290,000 6,180,000 3,240,000 2,240,000 3,100,000 19,700,000 3,280,000 3. 71 

Private: 

Consultants, utilities, 

and SBA disaster 

loans------------- 1,650,000 30,000 2,980,000 1,480,000 1,370,000 3,470,000 10,980,000 1,830,000 2.07 

Total-------- $3,300,000 $3,620,000 $9,160,000 $4,720,000 $3,610,000 $6,570,000 $30,680,000 $5,110,000 $5.80 

Percent of total 

that is private--- 50 33 

ferent parts of the landslide moved at different 

rates. The lower part moved at about the same 

rate that the now nearly stationary upper part 

had moved a year earlier. Federal, State, and local 

officials were concerned that the landslide would 

block Manti Creek and that subsequent large 

"breakout" flows of the creek would inundate a 

large part of the city of Manti with floods or 

debris flows. 

The concern over the potential blockage of 

Manti Creek precipitated a significant expenditure of money for analysis and preparation for a 

disaster that fortunately has not occurred. 

Various local, State, and Federal agencies worked 

on contingency plans and examined alternatives 

for remedial or preventive treatment of the 

unstable areas. The risk to the city of Manti was 

concluded to be small compared with the costs of 

any of several possible remedial plans, especially 

considering that the success of the plans could 

not be assured. 

Since the initial movement during 197 4 and 

rapid movement of the lower part of the landslide 

in 1975, the rate of movement has decreased. This 

supports the decision not to attempt to stabilize 

the moving ground or the channel of Manti Creek. 

However, a large fractured mass of rock remains 

in the canyon rim above the landslide, and a 

renewed cycle of movement could start if the 

events of 1974 were to be repeated. The landslide 

will likely continue to be a troublesome problem 

for many years to come. 

COSTS OF LANDSLIDE DAMAGE 

Although the landslide is 6.5 km (4 mi) from the 

nearest permanent dwelling, it has proven to be a 

31 38 53 36 36 -----------

19 

.A 

/\. 

-'\ 

-\ 

-'\ 

-'1,/ront of Wasatc~ Plateau 

2 KM 

2 Ml 

t 

N 

I 

FIGURE 6.-Map showing the Manti landslide, Mall ti Canyon, 

Utah. (Modified from Fleming and others, 1977.) 

costly problem for the Manti area. The broken 

waterline caused loss of revenue fr·om the 

hydroelectric system and has necnssitated 

development of an emergency water supply and 

replacement of the waterline. In addition, large 

amounts of debris introduced into the creek by 

the landslide resulted in the depo~·i.tion of 

sediments in the irrigation systems and 

agricultural fields downstream. Doc~lmented 

costs attributable to the landslide wer~ nearly 

$1.8 million by August 1976. Approximstely onethird of this cost was related to physical damage 

or cleanup work resulting from the earth movement. The greater portion, some $1.1 million, was 

spent for investigation of the landsHde and 

preparation for the potential disaster thB t did not 

occur. 

Additional funds have been expend"d since 

August 1976, but they are small in cmnparison 
TABLE B.-Sources of information on costs of landslide 

damage in Manti, Utah 

Source 

City of Manti: 

Mayor's office 

County of San Pete: 

Civil Defense 

Public Works Department 

State of Utah: 

Off ice of Emergency Services 

Utah Geological and Mineral 

Survey. 

Utah National Guard 

Source 

Federal Government: 

National Weather Service 

Soil Conservation Service 

U.S. Army Corps of Engineers 

U.S. Forest Service 

U.S. Geological Survey 

Off ice of Senator Hoss 

with funds spent earlier. This preliminary 

accounting of expenditures documents costs 

through August 1976; it does not, however, include some known losses that could not be 

evaluated and for which a cost could not be 

assigned. For example, on the landslide, a large 

number of trees were killed, a small reservoir was 

destroyed, and a few animals, mostly deer, were 

killed. Also, damage from siltation to cropland 

and the irrigation system was an undetermined 

cost. 

Costs of the Manti landslide were obtained by 

interviewing individuals in the different organizations known to have expended funds (table 8). In 

general, only one individual was interviewed in 

each governmental unit, and the information may 

not be complete. 

The costs attributable to the Manti landslide 

are summarized in table 9. The amounts listed are 

actual expenditures, except that the figure for the 

State of Utah includes an estimated value of 

$59,000 for service provided by the Utah National Guard. As part of their training, they 

donated manpower, equipment, and emergency 

water treatment units to the city of Manti. Including this amount seems appropriate because 

the services were essential and would have been 

required of another source if the Utah National 

Guard had been unable to cooperate. 

The costs to the city of Manti include $67,000 

directly attributable to landslide damage. The additional $816,000 includes funds for replacement 

of the waterline and valves, the drilling of a water 

well for an auxiliary water supply, and preventive 

maintenance on drainage channels. A 30.5-cm 

(12-in.) waterline was installed to replace the 

original line of 20.3 em (8 in.) and 25.4 em (10 in.), 

thus doubling the capability for water delivery. 

The installation of a new well and pump and a 

booster pump in the city of Manti provides a 

TABLE 9.-Expenditures by governmental agencies on the 

landslide in Manti Canyon (June 1974-August 1976) 

20 

Federal Government------------------------ $ 769,000 

State of Utah----------------------------- 76,000 

County of San Pete------------------------ 61,000 

City of Manti----------------------------- 883,000 

Total--------------------------------- $1,789,000 

standby water system not previously available. 

Some part of the cost should perhapf be assigned 

to upgrading the water-supply facilities and not 

be treated as landslide damage. However, the 

total amount has been included because the expenditure was precipitated by the landslide. If 

this results in an overstatement of costs attributable to the landslide, it is offset somewhat 

by undetermined costs associated with the loss of 

timber and siltation damage to crop1'ind and the 

irrigation system. 

The cost to the city and, therefore, to the 1,800 

residents of Manti was about $883,000 or nearly 

$500 per person. The total cost of the landslide, 

excluding the items that could not be defined, 

was about $1,800,000 or $1,000 pnr person in 

Manti. The costs were accrued oyer a 3-year 

period, making the average cost $33~ per person 

per year. Obviously, this was an ur'tsual event 

for Manti, and some estimate of recurrence 

should be applied to obtain a meaningful cost. 

Unfortunately, we do not know whether the landslide was a 50-, 100-, 500- or even a 1,000-year 

event. The range of per capita cost of landslide 

damage in Manti, U tab, is probably between $1 

and $20 per year. 

SUMMARY 

In those communities for which estimates of 

costs of damage have been compiled, the costs are 

much larger than generally believed l'y the public· 

and by government officials. SchustE'r' s estimate 

(1978), placing the national cost of landslide 

damage at in excess of $1 billion per year, is 

reasonable. 

In areas where landslide control programs have 

been implemented, however, they haYe proven effective in reducing damages. Communities that 

have landslide problems are encourag~d to assess 

the costs of damage to public and private property and weigh those costs against the costs of a 

landslide 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. 

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21 

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'tl U.S. GOVERNMENT PRINTING OFFICE 19E'0-677-1Z9J60