ANALYSIS OF GROWTH RATES OF RESIDENTIAL LAND
VALUES ON AND NEAR THE REGULATED FLOOD PLAIN
by
LARRY JAMES WARN ICK
A RESEARCH PAPER
submitted to
THE DEPARTMENT OF GEOGRAPHY
in partial fulfillment of
the requirements for the
degree of
MASTER OF SCIENCE
July 1977
1
ACKNOWL EDGMENTS
There are several people to whom I am indebted for their efforts in
the research for and writing of this report.
I wish to thank Dr. Keith
Muckleston, my major professor, for fostering my interest in flood plains
and for his encouragement, timely comments, and criticisms in the completion of the project.
The help and cooperation from the staff in general,
and Joe Trost in particular, at the Clackamas County Assessor's office is
sincerely appreciated.
A special thanks goes to Connie Burke for the
extended use of her typewriter, and finally, to Ruthanne Rubenstein for
her infinite patience, editing skills, and long hours at the typewriter.
11
TABLE OF CONTENTS
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LIST OF FIGURES .
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LIST OF TABLES
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INTRODUCTION.
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ACKNOWLEDGMENTS.
ABSTCT. .
STATEMENT OF THE PROBLEM AND OBJECTIVES .
STATEMENTOF HYPOTHESES...... .
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METHODOLOGY
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The Flood Hazard District
5 1 t e Se lee t ion .
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ANALYSIS OF VALUEDATA
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Collection and Computation of Land Values
VALUE DATA
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The Basic Procedural Format
Study Years
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Analysis of Site 1 Value Data
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Analysis of Site 2 Value Data
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ANALYSIS OF TEST RESULTS
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CONCLUSIONS .
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COMMENTS
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FOOTNOTES
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APPENDIX A
APPENDIX B
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APPENDIX C
APPENDIX D
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APPENDIX E
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APPENDIXF
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LIST OF FIGURES
FIG. 1
GENERAL SITE LOCATION MAP
F1G. 2
SITE 1
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F1G. 3
SITE 2
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FIG. 4
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COMPARISON OF VALUE APPRECIATION RATES TO SELECTED EVENTS
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LIST OF TABLES
TABLE 1
SITE 1 MEAN RATES OF LOT VALUE APPRECIATION
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TABLE 2
SITE 2 MEAN RATES OF LOT VALUE APPRECIATION
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TABLE 3
SITE 1:
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NUMBER OF LOT VALUE CHANGES BY
ASSESSMENTINTERVAL
TABLE 4
SITE 2:
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NUMBER OF LOT VALUE CHANGES BY
ASSESSMENTINTERVAL
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ANALYSIS OF GROWTH RATES OF RESIDENTIAL LAND
VALUES ON AND NEAR THE REGULATED FLOOD PLAIN
ABSTRACT.
Flood plain regulations are one of six major adjustments
used to cope with flood hazard in the United States.
This adjust-
ment was essentially neglected in the national flood hazard policies
until Congress enacted the National Flood Insurance Act of 1968.
The implementation of regulations, as called for in the Act, has
been slow.
One possible reason for the slow pace of implementation
is that there has been little evidence regarding the influence of
regulations on land values.
This study sought to determine, for
two selected sites on the Willamette River, whether land values of
flood plain parcels have been responsive to the implementation of
flood plain regulations.
The measure of responsiveness was the
assessed land value appreciation rates.
Statistical analysis showed
that, subsequent to the implementation of regulations, parcels on
the regulated flood plain tended to appreciate in value at rates
less than those of parcels near the regulated flood plain.
Prior
to enactment of flood plain regulations, the flood-prone parcels
tended to appreciate more than nearby parcels from above the
100-year flood plain.
INTRODUCTION
The flood plain is probably the most widespread natural hazard area
in the United States.
It has been estimated that there are approximately
20,000 flood-prone communities in the nation.
One out of every six acres
in urban areas is within the 100-year natural flood plain, covering an
2
area of about 16,500 square miles.1
The type and severity of flood hazard varies from region toregion.
The means by which these flood hazards are dealt with, collectively
known as adjustments, also differ among regions.
There are six major
types of adjustments currently utilized in the United
States0
These are:
control and protection works; flood-proofing buildings and their contents;
forecast and warning systems; land use management, including land plan-
ning and land treatment upstream; flood insurance; and relief and rehabilitation services.2
One of the most important, and promising, is the
regulation of the use of flood plain lands.
Only since 1960 has it been
recognized in federal policies and programs regarding flood hazard mitigation as a viable alternative to structural
adjustments0
Flood plain management was officially introduced into the nation's
flood hazard policies in the Flood Control Act of 1960.
That Act started
the Flood Plain Information Office in the Corps of Engineers, and authorized it to compile and disseminate flood information to responsible
non-federal entities.3
In 1966, a Task Force Report entitled A Unified
National Program for Managing Flood Losses (HD 465) advocated proper
management of flood plain lands as one of five topics of recommendations
aimed at bringing balance to the nation's flood hazard policies.4
Sub-
sequent to HD 465, implementation of flood plain regulations was slow.
With the enactment of the National Flood Insurance Act of 1968, the
federal government offered the economic incentive of federally subsidized
flood insurance for increased implementation of flood plain regulations.
As a prerequisite for obtaining the subsidized insurance, each city or
county had to implement several specified regulatory measures which
.5
applied to the flood plain.
3
Until 1973, participation in the flood insurance program was optional.
The Flood Disaster Protection Act of 1973 essentially made participation
mandatory for all cities and counties subject to flood hazard.
Provisions
in the Act specified that after a community is identified by the Federal
Insurance Administration as flood-prone, it must qualify for the insurance program or lose all federal financial assistance for construction
or acquisition of buildings in the designated flood hazard districts.6
In spite of repeated demonstration of the need for flood plain management and the federal insurance program, and its current mandatory
status, the program has not gained widespread acceptance.
If implemented
it could become a vital cog in the nation's adjustments to flood problems,
because it is the only one designed to modify future development on flood
plain areas.
STATEMENT OF THE PROBLEM AND OBJECTIVES
Perhaps one reason for the lack of acceptance of the flood insur-
ance program is the limited knowledge about possible repercussions which
might result from the implementation of flood plain regulations.
One
such possibility is decreasing land values of parcels situated on the
regulated flood plain.
A generally accepted notion is that restrictions imposed upon land
reduce the expected economic gains and thus reduce the land value.
Reg-
ulations imposed upon flood plain lands are restrictive and, accordingly,
are assumed to induce a negative influence on the values of the restricted
parcels0
There is little evidence to support such a
notion0
This study is designed to determine, for selected sites, whether or
not flood plain parcels have been responsive to the implementation of
4
flood plain regulations through the reduction of value appreciation rates.
The first objective is to design a standardized set of procedures, applicable throughout the state of Oregon, for evaluating the value appreciation rates of private residential land parcels on regulated flood plains
as compared to those of adjacent, unregulated private residential parcels.
The second is to provide a case study of selected sites on the Willamette
River, Oregon0
The results from the selected study sites will be used to determine
if there have been significant differences in the rates of change in
value between the regulated properties and adjacent unregulated parcels
during all, or various segments of, the period 1960 to 1976.
Second,
they will be used to determine whether any differences occurred in association with the implementation of flood plain regulations in the selected
study areas.
Finally, they will help discover any changes in the rate
of value appreciation of the flood plain parcels that occurred in con-
junction with significant flood events that took place during the study
period.
STATEMENT OF HYPOTHESES
The primary hypothesis is that the rate of appreciation in the land
value of private residential real property for parcels within the regu-
lated flood plain is less than that of adjacent, unregulated private
parcels0
There are also two secondary
hypotheses0
The first is that
the most significant differences in the value appreciation rates will be
between regulated and unregulated parcels contiguous with the line delineating the regulated flood plain.
The second is that statistically
significant differences in rates of value change between the regulated
and unregulated parcels will reflect the dates of implementation of flood
plain regulations and major flood events affecting the selected study
sites during the study period.
METHODOLOGY
There have been several previous investigations dealing with the
general topic of land values and flood hazard.
Many of the studies were
concerned with the estimation of benefits from flood control structures,
while others were attempts to isolate the specific effects of a particular aspect of flood and flood hazard mitigation on land values.
Clarenbach (1954) studied the relationships between benefit estimation
techniques for structural protection measures and land prices in protected areas.7
Struyk (1971) investigated flood control benefits for
agricultural lands and land values.8
Greenberg, et al. (1974) analyzed
the methods used for estimating the benefits of floo,d protection for
urban flood plains.
They also attempted to isolate the effect of flood
risk on property values in St. Louis County, Missouri.9
Shabman and
Damianos (1976) sought to estimate the influences of flood hazard reduction alternatives on sales prices of residential lands.1°
Boyet, et al.
(1976) reported on the impact of flooding upon land values.11
All of the previous studies utilized some variation of regression
analysis to measure the effects of flood hazard on land values.
In none
of the studies were the effects of public policies, such as flood plain
regulatory measures, isolated.
This study is not an attempt to isolate
the effects of flood plain regulations on land values in terms of a
specific dollar per acre figure.
Rather it is a trend analysis designed
to compare the relative value appreciation rates of regulated and unreg-
ulated parcels with respect to the implementation of flood plain regulations on selected sites.
The Basic Procedural Format
The following is a synopsis of the order of procedures used in this
study.
Subsequent sections will provide details and descriptions of the
procedures and data inputs for the study.
(a)
Adequate study sites and the study period were selected, based
on criteria that will be discussed in detail in following sections;
(b)
all parcels in the selected sites that had, for any reason,
changed size or shape during the study years were omitted from consideration;
(c)
assessed lot values for all of the parcels included in the
study were collected for each year of assessment that occurred during
the study years;
(d)
the total study period was broken up into several significant
time spans.
The assessed lot values for all of the parcels were then
converted to percentage rates of appreciation for each time span;
(e)
the mean rates of lot value appreciation for each time span
were calculated for both the regulated and the unregulated parcels;
(f)
the mean rates of lot value appreciation for the two groups of
parcels, for each time span, were then tested to determine if any statistically significant differences existed between the two (see Appendix E
for description of the statistical tests);
(g)
12
any visible trends and/or differences were compared to the
dates of implementation of flood plain regulations applying to the study
areas and to major flood events affecting the sites during the study period.
7
Study Years
Two flood plain areas on the Willamette River in Clackamas County,
Oregon, were selected for investigation.
The study period was from 1958
to 1976 for one area, and from 1957 to 1976 for the other.
The difference
of one year was because of the availability of assessed lot values for
the two areas.
The two-decade study period (19 years for one site) was
chosen for several reasons.
First, it was intended that the time range
coincide with the beginnings of the shift of the national flood hazard
policies, which began around 1960.
Second, the initial years of the study
preceded the implementation of regulatory measures by well over a decade.
This was important because it allowed for value appreciation rate comparisons for several time spans before, during, and after the implementation
of flood plain regulations.
Finally, the assessed lot value records were
available for those years.
The Flood Hazard District
The flood plain, the regulated flood plain, the 100-year flood plain,
and the Flood Hazard District (FHD) are all used interchangeably in this
report (see Appendix A).
The source for the delineation of the FHD was
a study by the Corps of Engineers (l970).13
For purposes of this study,
the parcels within the FHD and the parcels outside the FHD were separated
for the entire time period from 1957-58 to 1976.
there was no FHD before 1971 in either study area.
Technically, however,
Naturally, the fact
that the 100-year flood plain had not been designated as the FHD did not
detract from the
hazard0
Therefore, the differentiation between parcels
on either side of the mythical line for values prior to 1971 was made so
that all comparisons of appreciation rates would remain consistent.
Site Selection
The following criteria were used for selection of the two study
sites (see Figure 2)
(a)
For ease of travel time and expenses, all sites had to be in
the Willamette Valley and in relatively close proximity to one another;
(b)
the sites had to be existing residential areas with little or
no commercial or industrial development.
The two selected areas had no
development other than residential;
(c)
the 100-year flood plain boundary etablishing the regulated
Flood Hazard District, as delineated by the Corps of Engineers, had to
bisect the selected areas;
(d)
the areas had to be subject to flood plain regulatory measures;
(e)
the desired assessed lot values for all of the parcels in
and
question had to be available from the appropriate County Assessor.
The two selected study sites are located on the Willamette River in
Clackamas County near the city of Lake Oswego (see Figure l)
Site 1
(see Figure 2) is on the east side of the river across from Lake Oswego.
Site 2 (see Figure 3) is on the west bank of the river, just north of
Lake Oswego.
Both areas are in the jurisdiction of the Clackamas County
Planning Department.
The parcels that were included in the study were those that had
remained unchanged in size and/or shape for the entire study period.
Those that were omitted from consideration had been subdivided or had
changed shape through road construction or consolidation with another
parcel(s).
In a few instances, parcels eligible for consideration were
omitted because of errors in the records at the County Tax Assessor's
office.
For detailed descriptions of the parcels in each study site,
see Appendix D.
Collection and Computation of Land Values
The source of land value data was assessed lot values, which were
collected from the Clackamas County Assessor's office.
They were used
as the data source for several reasons, first of which was that they are
the most comprehensive source of land value data available on a statewide
basis.
Second, they are also divided into lot and improvement values,
which was essential, because this study was focused on the land (lot)
values only.
No sales prices were used because of incomplete records
dating back through the study years, although sales records might have
expressed the actual market values more accurately than assessed values.
For the purposes of this study, however, assessed values were assumed to
represent the true cash value of the parcels of interest.
Assessed lot values were collected for Site 1 for the years 1958,
1962, 1965, 1969, 1972, and 1976.
For Site 2, values were collected for
the years 1957, 1961, 1965, 1968, 1970, and 1976.
The values for those
particular years were utilized because they were, for the most part, the
years of reassessment for the parcels in the selected sites.
There were
a few exceptions that should be noted, however.
Prior to 1968, Clackamas County assessed land at 25 percent of its
market value, but has since been assessing land at 100 percent of its
true cash value.
To compensate, all values collected for years prior to
1968 were multiplied by four.
Secondly, values for the years in between
reassessment years were not listed in the records before 1968 and were
assumed by the County Assessor to remain constant until the next
FIGURE 1.
GENERAL SITE LOCATION MAP
2 IE
RY
AIN BOUNDARY
3ER
FIGURE 2.
PARCELS OMITTED FROM STUDY
SITE 1
200
300 m
290
100
0
400
SCALE
600
a6o
idoo ft
3600
/
3600
'O
'>3
/
300
I
I
,
I
400
/
500
/
/
II
/
/
600
I
700
I
I
/
I
/
800
600
900
,
/
700
II
/
3100
100
200
/ lOO
3000
200
/
'00
12Q
/
I
14
2 IE 2BA
I
35o
7
900
100
/
2IE2BB
/
/
1
2000
I
F
2Go
,1/
/ 2, <'0
,
// 2700
2400
1
,
100
/
FQ
0
I
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/
/
I
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0Q
2IE2BD
/
,1
0o
/
LEGEND
600
STUDY SITE BOUNDARY
2BC
K
100-YEAR FLOOD PLAIN BOUNDARY
21>
TAX LOT NUMBER
1700
2 IE 2BB
/1/
TAX LOT MAP NUMBER
SOUTHERN PACIFIC RAILROAD
I
I
PARCELS OMITTED FROM STUDY
o
0
200
460
SCALE
/1
FIGURE 3.
200
100
SITE 2
660
3?0m
860
i000ft
13
assessment.
In 1965, less than half of the parcels under investigation
were reassessed, leaving the remainder of the parcels with the previous
assessed value.
Of the parcels that were reassessed in 1965, nearly all
were within the 100-year flood plain.
Since 1968, parcel values for the years in between reassessments
have been appreciated through the application of blanket percentage increases each year.
Because of the recent effort by the County to assess
land at ± 5 percent of its market value, which has been required by law
since 1968, the lot values from 1970 on are probably more reliable than
the earlier values.
Once the collected lot values were corrected to represent 100 percent value, they were calculated into mean rates of value appreciation
for several time spans within the overall study period.
used for Site 1 were:
1976, and 1958 to 1976.
The time spans
1958 to 1969, 1962 to 1972, 1965 to 1976, 1972 to
The time spans used in the tests for Site 2 were:
1957 to 1968, 1961 to 1970, 1965 to 1976, 1970 to 1976, and 1957 to 1976.
The individual assessed lot values were converted into mean rates
of value appreciation in the following manner.
First, for each individ-
ual parcel for each time span, the assessed value of the most recent
year was expressed as a percent of the value of the earlier year.
Next,
mean percentages were calculated for both regulated parcels and for unregulated parcels for each of the time spans.
The pairs of means for
each time span were then tested for statistically significant differences.
VALUE DATA
The calculated mean rates of value appreciation for the various
groupings of parcels within each site are displayed in Tables 1 and 2.
14
In addition to the percentage figures shown in Tables 1 and 2, further
insight into the times within the study period during which most of the
lot value appreciation took place is given in Tables 3 and 4.
Here, the
parcels are classified as either below or above the 100-year flood plain
boundary.
For each assessment interval is listed:
the number of parcels
with lot value increases, those with value decreases, and those with no
change of
value0
See Appendices B and C for complete listings of indi-
vidual parcel values and rates of appreciation.
Figure 4 displays the
relative value appreciation rates for each time span compared to the
dates of selected flood, legislative, and administrative events and actions
that may have affected the study sites.14
ANALYSIS OF VALUE DATA
Several significant patterns are evident upon examination of Tables 1
through 4 and Figure 4.
During the examination of the value data, it
should not be forgotten that, even though the FHD was not enacted until
1971, the 100-year flood plain was used as the dividing line between the
flood plain parcels and the parcels adjacent to the flood plain.
Analysis of Site 1 Value Data
This area had more observations than Site 2, and, therefore, the
data and results are probably more reliable.
first in the analysis of Site 1.
Table 3 should be inspected
This shows that, with the exception of
the 1962-1965 assessment interval, the two groups of parcels were almost
identical in the type of value changes each parcel exhibited for each
interval.
Nearly every parcel, as might be expected, appreciated in
assessed lot value from 1958 to 1962.
The drastic change to a lot value
depreciation of about 70 percent of the 100-year flood plain parcels and
TABLE 1.
SITE 1 MEAN RATES OF LOT VALUE APPRECIATION
Time Segments
1958-1969
Parcel Group
1962-1972
1965-1976
1972-1976
1958-1976
l637
3827
l897
l,9l57
All FHD Parcelsa
5O97
FHD:
Waterfront
4897
l867
l,8797
FHD:
Adjacent to FHD Line
6O97
2O47
2,2577
2O77
l,4767
2l77
2,3O77
1970-1976
1957-1976
38l7
All Non-FHD Parcels
Non-FHD:
Adjacent to FHD Line
2l77
44570
5467
1971.
a
This coincides with parcels on 100-year flood plain prior to
b
This includes 17 lakefront parcels along with 34 riverfront parcels.
TABLE
2.
SITE 2 MEAN RATES OF LOT VALUE APPRECIATION
Time Segments
Parcel Group
1957-1968
1961-1970
1965-1976
All FHD Parcels
l767
l487
38l7
23O7
47370
All Non-FHD Parcels
l447
l427,
3l57
2197,
43470
TABLE 3.
SITE 1:
NUMBER OF LOT VALUE CHANGES BY ASSESSMENT INTERVAL
Assessment Intervals
Type of Lot Value Change
1958-1962
1962-1965
1965-1969
1969-1972
1972-1976
Parcels in 100-Year Flood Plain
Value Appreciation
76
0
2
74
75
No Change in Value
0
23
72
0
0
Value Depreciation
0
53
1
1
0
Values Not Available
0
0
1
1
1
Parcels Above 100-Year Flood Plain
Value Appreciation
72
0
4
80
81
No Change in Value
2
74
74
0
0
Value Depreciation
0
4
2
1
0
Values Not Available
7
3
1
0
0
TABLE 4.
SITE 2:
NUMBER OF LOT VALUE CHANGES BY ASSESSMENT INTERVAL
Assessment Intervals
Type of Lot Value Change
1957-1961
1961-1965
1965-1968
1968-1970
1970-1976
Parcels in 100-Year Flood Plain
Value Appreciation
27
0
23
34
37
No Change in Value
0
15
14
0
0
Value Depreciation
7
21
0
3
0
Values Not Available
4
2
1
1
1
Parcels Above 100-Year Flood Plain
Value Appreciation
11
0
3
14
17
No Change in Value
0
16
12
1
0
Value Depreciation
3
0
1
2
0
Values Not Available
3
1
1
0
0
(I)
4J
Q)
qj
(N
Cl)
q)
Q)
4_)
r4
C))
.r-4
0
0
C))
q)
>
U
p
ctj
C))
Q)
C))
cj
qj
Q)
4J
p
(_)
U)
Q)
z
Site 2 Years 1953
Site 1 Years
65
61
62
76I
170
I
1958
65
I
I
69
I
'I
72
Study Period
a
Floods on Willamette River- December 1964, January 1965
b
Change in Clackamas County assessment procedures
c
National Flood Insurance Act of 1968
d
Enactment of Flood Hazard District- 12/21/71
e
Comprehensive Plan- 8/7/74
d
Comprehensive Plan amended- 12/13/76
FIGURE 4.
COMPARISON OF VALUE APPRECIATION RATES TO SELECTED EVENTS
76
19
an almost complete "no change" of value for the off-flood plain parcels
during the next interval coincided with the catastrophic floods of 1964
and 1965.
Apparently, the effects of the floods on land values lingered
through the 1965 to 1969 assessment interval, because both groups of
parcels, with a few exceptions, had no lot value change.
This period
also marked the change in assessment procedures in Clackamas County.
During the 1969 to 1972 and the 1972 to 1976 assessment intervals,
every parcel in both groups, with the exception of two, appreciated in
value.
The introduction of the FHD occurred before the last interval.
In spite of that, all FHD parcels continued to appreciate, as did all of
the non-FHD parcels.
Table 1 displays five time intervals, three of which are approximately
a decade in length.
The 1958 to 1969 period shows that, despite the fact
that nearly all of the Site 1 parcels appreciated initially and the flood
plain sites depreciated midway through the period, the three groups of
flood plain parcels appreciated more than their off-flood plain counterparts.
This was reversed during the 1962 to 1972 period.
During that time,
the post-flood value depreciations of most of the flood-prone sites were
most evident.
The All Non-FHD Parcels appreciated significantly more
than the All FHD Parcels, at mean rates of 217 percent and 163 percent,
respectively.
The third interval, 1965 to 1976, showed that the Non-FHD
Parcels continued to increase faster,
The difference was not statisti-
cally significant, however.
The 1972 to 1976 period is probably the most accurate, because of
the shorter time span and thus smaller variances, and because of the
assessment procedure changes in 1968.
In this period, all of the parcels
appreciated in value, but the groups of Non-FHD Parcels appreciated more
20
than the FHD counterparts.
These results are significant, because they
show that subsequent to the enactment of flood plain regulations in 1971,
the regulated parcels appreciated in value relatively less than the
unregulated parcels.
Analysis of Site 2 Value Data
The size and physical setting of Site 2 made it much less conducive
to the variety of tests performed on the data from Site 1.
The linear
shape of the study area made the division of sub-groups impossible, since
nearly all of the FHD parcels were both waterfront and adjacent to the
FHD line.
Table 4 shows that the types of lot value changes for the two groups
of parcels for each assessment interval were similar to those of Site 1.
Again, the initial interval showed that nearly all of the parcels in the
site experienced value appreciations.
During the 1961 to 1965 interval,
the majority of the FHD parcels depreciated, while the remainder of the
FHD and all of the Non-FHD parcels did not change in value.
As with the
comparable Site 1 interval, this coincided with the floods of 1964 and
1965.
The 1965 to 1968 interval displayed a quick recovery of value for
the FHD parcels, where 23 of 37 parcels appreciated in value.
The Non-FHD
parcels did not tend to appreciate, however, as 12 of 16 parcels failed
to change in value through the interval.
The final two assessment inter-
vals were consistent with Site 1 because both groups of parcels appreciated, with only a few exceptions from 1968 to 1970.
As before, the FHD
parcels continued to appreciate in lot value despite the enactment of
flood plain regulations.
Table 2 shows that the FHD parcels appreciated more than the Non-FHD
21
parcels for each time segment.
The first decade interval was consistant
with Site 1, as the FHD parcels appreciated more than the Non-FHD parcels,
although the difference was not significant.
The trend continued through
the next time segment of 1961 to 1970, as the occurrence of the catastrophic floods did not seem to restrain the rapid appreciation of the
FL-ID parcels in relation to the growth of the Non-FHD parcel values.
Also,
the enactment of the FHD and related regulations did not appear to influence the mean lot value appreciation rates during the 1970 to 1976 segment,
since the FUD parcels continued to appreciate at a quicker pace than the
Non-FHD parcels.
This was an interesting and unexplainable contrast to
the value appreciation rates for Site 1.
ANALYSIS OF TEST RESULTS
Sixteen statistical tests, eleven on the Site 1 mean appreciation
rates and five on the Site 2 mean rates, were conducted to test the validity of the study hypotheses.
The null hypothesis for all of the tests
was that the mean rates of lot value appreciation for FHD parcels was
equal to the mean rates of lot value appreciation for Non-FHD parcels.
See Appendix F for summary of the individual test results.
In four of the Site 1 tests, the null hypothesis was rejected, mdicating significant differences between the respective mean values.
The
first was for the initial time span 1958 to 1969 and showed the mean rate
of the FHD parcels at 5097. as significantly different from the mean rate
of Non-FHD parcels at 3897..
The mean appreciation rates for the two
groups of parcels were also significantly different for the next time span
of 1962 to 1972, except that the Non-FHD mean was high.
The impact of the
1964-1965 floods are most apparent during that time period.
22
The two most important test results, in terms of the study hypotheses,
are from the tests comparing the All FHD parcels- to the All Non-Fl-ID par-
cels and the Waterfront Only parcels to the All Non-FHD parcels for the
time span 1972 to 1976.
Both tests indicated significant differences
between the respective mean rates with the Non-Fl-ID values being higher in
both instances.
Both tests show that, subsequent to the enactment of reg-
ulations, the unregulated parcels adjacent to the FHD appreciated in value
significantly more than the regulated parcels in the FHD.
All five tests conducted with the Site 2 data indicated that there
were no statistically significant differences between the mean rates of
value appreciation for the FHD parcels and the Non-FHD parcels.
CONCLUS IONS
The Site 1 data and test results supported two of the three study
hypotheses.
The primary hypothesis was supported by the test which shoved
that there was a statistically significant difference between the mean
rates of appreciation of the Fl-ID and Non-FHD parcels for the time segment
1972 to 1976.
The difference between the two means was a complete rever-
sal from the result of the test for the 1958 to 1969 time segment, in
which the parcels on the 100-year flood plain increased in value significantly more than the parcels above the 100-year flood plain.
The first of the secondary hypotheses was not supported by the test
results, as there was no significant statistical difference between the
mean rates of lot value appreciation for any of the time segments tested.
The second of the two secondary hypotheses did receive support from the
data tables and test results.
The value data and test results for Site 2 failed to either support
23
or refute the study hypotheses.
In each of the five time segments, the
mean assessed value appreciation rates for the FHD parcels were more than
those for the Non-FHD parcels.
The differences in the respective means
were not statistically significant.
In summary, the FHD parcels generally appreciated at a rate less than
that of the Non-FHD parcels subsequent to the implementation of flood
plain regulations on the selected study sites.
There was no evidence
that supported the hypothesis that the most significant differences in
the value appreciation rates would be between regulated and unregulated
parcels on either side of the line delineating the regulated flood plain.
Thirdly, the statistically significant differences in mean rates of value
appreciation did reflect major flood events and the implementation of reg-
ulations in one of the two study sites.
C OMNENTS
The events that appeared to affect the lot values of the parcels in
both study areas most drastically were the floods of 1964/1965.
The detri-
mental effects of flooding on land values has been documented many times,
and this study offers yet another example.
The test results from the two study sites were not entirely consistent.
The data and results for Site I tended to support the hypotheses,
while the results for Site 2 were inconclusive.
The results for Site 1
are probably more reliable than for Site 2 because of the larger number
of parcel observations.
This one selected instance displaying the respon-
siveness of land values of regulated parcels to the implementation of flood
plain regulations relative to those of nearby unregulated parcels merely
scratches the surface of the research that needs to be completed.
24
FOOTNOTES
1
James E. Goddard, "The Nation's Increasing Vulnerability to Flood
Catastrohpe," Journal of Soil and Water Conservation, March-April
(1976), Vol. 31, Number 2, p. 48.
2
Gilbert F. White, Flood Hazards in the United States:
A Research
Assessment, Program on Technology, Environment, and Man,
Monograph # NSF-RA-E-75-0O6 (Institute of Behavioral Science, The
University of Colorado, 1975), p. 7.
3
Keith W. Muckleston, "The Evolution of Approaches to Flood Damage
Reduction," Journal of Soil and Water Conservation, March-April (1976),
Vol. 31, Number 2, p. 54.
4
U. S. Congress, A Unified National Program for Managing Floods,
H. Doc. 465, 89th Cong., 2d Session, Washington, D. C., 1966.
5
Rod Emmer, Problems and Issues of Implementing the National Flood
Insurance Act in Oregon, (unpublished doctoral dissertation, Oregon
State University, 1974), p. 14.
6
Muckleston, "The Evolution...," footnote 3, p. 56.
7
Fred Clarenbach, Reliability of Estimates of Agricultural Damage from
Floods, Task Force Report on Water Resources and Power, Vol. III,
Commission on Organization of the Executive Branch of Government,
1954, pp. 1277-98, cited by Demetrios Damianos and Leonard A. Shabman,
Land Prices in Flood Hazard Areas:
Applying Methods of Land Value
Analysis, Bulletin 95 (Blacksburg:
Virginia Water Resources Research
Center, 1976), p. 4.
8
Raymond J. Struyk, Agricultural Flood Control Benefits and Land Values,
U. S. Army Engineer Institute for Water Resources, (Alexandria,
Virginia, 1971).
25
9
Edward Greenburg, Charles L. Levin, and Alan Schlottmann, Analysis of
Theories and Methods for Estimating Benefits of Protecting Urban Flood
Plains, IWR Pamphlet No. 3, (St. Louis:
Washington University,
Institute for Urban and Regional Studies, 1974).
10
Demetrios Damianos and Leonard A. Shabman, Land Prices in Flood Hazard
Areas:
Applying Methods of Land Value Analysis, Bulletin 95,
(Blacksburg:
Virginia Polytechnic Institute and State University,
Virginia Water Resources Center, 1976).
11
Wayne Boyet, Kenneth W. J4ollman, and Wayne L. Sterling, The Impact of
Flooding Upon Land Values in the Big River Basin, (Mississippi State
University, Water Resources Research Institute, 1976).
12
William Mendenhall, Lyman Ott, and Richard F. Larson, Statistics:
A Tool for the Social Sciences, (North Scituate, Massachusetts:
Duxbury Press, 1974), pp. 264-69, 305-08.
13
U. S. Army Corps of Engineers, Portland District, Flood Plain
Information:
Willamette River, Johnson, Kellog, and Mt. Scott Creeks,
Milwaukie, Oak Grove, Lake Oswego, Oregon, (Portland, 1970), plates 8-11.
14
Following are the sources from which the information in the time-line
in Figure 4 was derived.
U. S. Army Corps of Engineers, Portland District, Postflood Report:
December 1964, January 1965 Flood, (Portland, 1966), p. 73.
Emmer, Problems and Issues..., footnote 5, pp. 106-10.
This provides
detailed discussion of the Clackamas County regulations in comparison
with the most restrictive standards of the FIA.
Clackamas Board of County Commissioners, Clackamas County Zoning
Ordinance Amendment, Final Court Order No. 71-1151, December 12, 1971.
Clackamas Board of County Commissioners, Comprehensive Plan Amendment,
Court Order No. 77-136, December 13, 1976.
26
APPENDIX A
WORKING DEFINITIONS
*
Flood - The condition existing when the waters of a watercourse,
drainway, lake or ocean temporarily arise to unusual heights
above the normal level of such watercourse, drainway, lake or
ocean.
The rise in water may be caused by excessive rainfall,
snbwmelt, natural stream blockages, ocean wind storms, tsunamis,
extremely high tides, or any combination of such conditions.
*
Flood Hazard - A general term meaning the risk to life or property
caused by flooding.
*
Flood Hazard Area - An area where risk to life or property exists
because of possible flooding.
Flood Hazard District (FHD) - The areas subject to Section 29 of the
Clackamas County Zoning Ordinance Amendment (Final Court Order
No. 71-1151), which established three sub-classifications of land
within the 100-year flood plain.
They are the floodway, the flood
fringe, and where differentiation between the two is not possible,
flood hazard district.
Flood Insurance - Insurance on structures and facilities for the
restoration or replacement of those facilities if damaged by floodwater.
The term is usually applied to federally subsidized flood
insurance under the Housing and Urban Development Act of 1968, as
administered by the Department of Housing and Urban Development.
*
Flood Plain - The area adjoining a river, stream or watercourse
which may be subject to periodic inundation by floodwaters.
*
Flood Plain Management - A combination of all of the practical flood
damage reduction measures.
This combination will vary in different
27
areas, depending on existing and proposed use and development of
the flood plains and the availability of feasible flood control
possibilities.
Sometimes refers to nonstructural flood damage
reduction measures only.
*
Flood Plain Regulations - Legal tools by which flood plain use and
development can be regulated, including land use zoning, building
codes provisions, subdivision regulation provisions, health code
provisions, and exercise of other regulatory authorities with
respect to flood prone areas.
*
Flood Prone Area - The area or lowlands adjoining a river, stream or
watercourse, lake or ocean which may be subject to periodic
inundation by floodwaters.
One-Hundred Year Flood (Intermediate Regional Flood) - A flood
occurring on the average of once in 100 years and having a one
percent chance of occurring in any single year.
It is based on
a statistical analysis of available streamfiow records or analysis
of rainfall and runoff characteristics in the general region of
the watershed.
Sometimes referred to as a regional flood.
*
Regulation of Flood Plain Use and Development - Regulation of land
use and development in flood plain areas to insure that any use
and development is compatible with the flood hazard that exists
in the area as well as with the land use plan for the area.
*
State Water Resources Board, Oregon's Flood Plains:
A Status Report
and Proposed Flood Plain Management Program, Dec. 1972.
**
Clackamas Board of County Commissioners, Clackamas County Zoning
Ordinance Amendment, Final Court Order No. 71-1151, Dec. 12, 1971.
APPENDIX B
INDIVIDUAL PARCEL ASSESSED VALUES
Site 1 Regulated Parcels
1958
Parcel No.
1962
1965
1969
1972
1976
Map 2 lE 11BA
280
$ 9,280
$ 6,520
$ 6,520
$ 8,500
$19,000
700
2,000
8,680
6,480
6,480
7,500
13,500
800
2,000
6,440
4,520
4,520
7,000
16,500
1900
2,000
7,160
5,000
5,000
8,000
16,500
2000
2,120
7,160
5,360
5,360
9,200
16,500
2100
2,120
7,160
5,000
5,000
8,500
17,000
2200
2,120
7,280
5,080
5,080.
7,500
16,000
2300
2,120
7,920
5,520
5,520
9,000
15,000
4700
480
3,520
2,480
2,480
5,800
9,000
4800
2,000
9,600
6,680
6,670
12,080
19,500
4900
2,240
9,600
6,720
6,720
11,500
21,000
5000
2,480
10,520
7,360
7,360
11,500
22,500
5300
2,760
10,680
7,480
7,480
11,500
19,500
5400
2,480
10,800
7,560
7,560
12,000
20,500
5500
2,320
10,920
8,200
8,200
12,000
20,500
5600
80
3,600
2,520
2,520
6,500
9,500
5700
440
2,360
1,800
1,800
5,000
10,000
6000
120
3,120
2,160
2,160
7,000
11,000
6100
520
3,640
2,920
2,920
6,500
10,000
480
2,640
2,640
2,640
5,500
15,000
600
$
Map 2 1E 11BD
1600
29
1958
Parcel No.
1965
1969
1972
1976
280
$ 3,840
$ 3,840
$ 3,840
$ 7,500
$16,000
1800
280
3,520
3,520
3,520
6,000
16,000
1900
600
3,840
3,840
3,840
7,500
16,000
2000
N/A*
3,080
3,080
3,080
7,000
16,000
2700
200
2,440
1,840
1,840
4,000
6,000
2800
1,600
6,640
5,000
5,000
16,000
25,000
2900
800
5,000
3,760
N/A
N/A
20,000
3000
600
4,240
3,400
3,400
8,000
18,000
3100
880
3,960
3,160
3,160
8,000
18,000
3200
280
640
520
520
1,400
7,500
3300
360
2,560
1,920
1,920
4,000
8,500
3400
280
3,360
2,680
2,680
7,000
13,000
3500
800
4,560
3,440
3,440
9,780
14,000
3700
600
4,680
3,720
3,720
7,000
16,000
3800
200
3,200
2,240
2,240
7,500
13,000
4200
600
3,920
2,760
2,760
8,200
13,000
4300
600
3,720
2,520
2,520
8,000
12,500
4400
3,080
13,560
9,480
9,480
15,500
28,000
4500
1,920
9,400
6,600
6,600
11,000
20,000
4600
3,360
11,600
8,680
8,680
12,000
22,000
4700
2,480
10,520
8,920
8,920
12,000
20,000
4800
2,480
8,840
7,520
7,520
10,500
18,000
4900
2,520
9,840
8,360
8,360
11,500
20,000
5000
2,480
9,760
8,280
8,280
12,000
20,000
5100
2,480
9,760
8,760
8,760
12,000
20,000
1700
*
1962
$
No1 Available
30
Parcel No.
1958
1962
1965
1969
1972
1976
5200
$2,520
$ 9,920
$ 9,920
$ 9,920
$13,000
$20,000
5500
2,480
10,120
10,120
10,120
13,000
20,000
5600
2,480
10,120
10,120
10,120
13,500
20,000
5700
2,480
9,120
9,120
9,120
12,000
18,000
5800
840
3,320
3,320
3,320
5,500
8,500
6100
760
3,000
3,000
3,150
6,200
10,000
300
880
2,840
2,120
2,120
5,400
9,500
400
400
2,360
1,760
1,760
4,800
9,000
500
760
3,080
2,320
2,320
5,600
10,000
600
600
1,120
840
3,500
2,800
8,000
700
640
2,600
1,960
1,960
4,800
9,000
800
640
2,000
1,600
1,600
4,400
7,500
1100
760
3,080
3,080
3,080
5,000
9,500
1200
440
2,720
2,720
2,720
4,500
8,000
1300
400
1,880
1,880
1,880
2,500
6,000
1600
600
3,240
3,240
3,240
5,500
10,000
1700
680
3,040
3,040
3,040
5,000
10,000
1800
760
3,000
3,000
3,000
5,000
10,500
2100
880
4,040
4,040
4,040
7,000
10,500
2200
880
3,760
3,760
3,760
7,000
10,500
2300
840
3,400
3,400
3,400
5,500
9,000
2400
840
3,400
3,400
3,400
5,500
9,000
2500
2,480
10,240
9,240
9,240
13,500
20,000
2600
2,480
10,280
9,240
9,240
13,500
19,500
2700
2,480
10,320
9,280
9,280
13,500
19,500
Map 2 1E 11CA
31
Parcel No.
1958
1962
1965
1969
1972
1976
2800
$2,480
$10,400
$10,400
$10,400
$12,500
$20,000
3100
1,760
5,800
5,240
5,240
22,000
55,680
3300
5,240
13,760
12,400
12,400
20,000
38,600
3600
2,080
6,640
4,640
4,640
12,500
25,000
4000
2,800
8,800
7,040
7,040
14,000
29,000
4100
520
1,760
1,760
1,760
4,500
7,500
Site 1 Unregulated Parcels
Map 2 1E 11BA
100
920
2,880
2,880
2,880
5,200
8,500
200
800
2,560
2,560
2,560
5,200
8,500
300
760
2,400
2,400
2,400
4,800
8,000
400
760
2,520
2,520
2,520
5,200
8,000
500
760
2,560
2,560
2,560
5,200
8,000
1100
N/A
1,640
1,640
1,620
3,200
7,000
1200
N/A
1,600
1,600
1,600
3,000
7,000
1300
320
1,760
1,760
1,760
3,200
7,000
1400
560
1,760
1,760
1,760
3,200
7,000
1500
560
1,600
1,600
1,600
3,000
7,000
1600
240
1,360
1,360
1,360
3,000
7,000
1700
240
N/A
N/A
320
500
3,000
1800
240
320
320
1,240
2,800
7,000
2600
600
2,200
1,640
1,640
3,800
7,000
2700
240
1,120
760
760
2,500
5,000
2800
240
1,120
760
760
2,500
5,500
3100
1,200
2,520
2,520
2,520
5,200
1,100
3300
640
2,400
2,400
2,400
4,800
8,500
32
Parcel No.
1962
1958
1972
1969
1965
1976
3,120
$ 3120
760
3,040
3,040
3,040
5,500
9,000
4100
760
2,880
2,880
2,880
5,000
8,500
4500
1,080
3,000
3,000
3,000
4,800
8,500
4600
N/A
1,640
1,640
1,640
4,600
8,000
6300
400
3,000
2,720
2,720
5,600
10,000
6400
520
2,720
2,720
2,720
5,600
10,000
6500
680
3,160
3,160
3,160
5,800
10,500
6600
400
3,200
3,200
3,200
5,600
9,500
6700
400
3,000
3,000
3,000
5,600
10,000
6800
160
2,600
2,600
2,600
4,600
8,500
6900
160
2,600
2,600
2,600
1,730
8,000
100
320
3,080
3,080
3,080
4,500
8,000
200
280
2,240
2,240
2,240
4,400
8,000
600
600
1,600
1,600
1,600
3,100
8,500
700
600
1,000
1,000
1,000
2,900
8,500
800
480
720
720
2,800
4,500
8,500
900
480
480
480
760
3,220
8,500
1200
N/A
N/A
3,160
3,040
5,600
9,000
1300
N/A
N/A
3,160
3,160
5,600
9,000
1400
240
2,360
2,360
2,360
4,600
8,000
1500
480
2,400
2,400
2,400
4,600
8,000
400
400
400
400
3,500
8,500
3900
$1,080
4000
$
$
1,500
$
3,600
$
7,000
Map 2 1E 11BD
Map 2 1E 11CA
100
33
Parcel No.
1958
1962
1965
1969
1972
1976
Map 2 1E 11AB
840
$ 2,920
$ 2,920
$ 2,920
$ 4,500
$10,500
900
960
2,480
2,480
2,480
4,200
9,000
1700
1,400
3,120
3,120
3,120
6,000
10,000
1800
880
2,400
2,400
2,400
4,600
9,000
1900
800
2,560
2,560
2,560
4,600
8,500
2000
2,520
4,680
4,680
4,680
11,000
16,000
2100
880
2,160
2,160
2,160
4,800
9,000
2200
880
2,240
2,240
2,240
4,800
9,000
2300
760
1,480
1,480
1,480
3,800
7,500
2800
1,760
3,560
3,560
3,560
5,000
11,000
2900
760
2,480
2,480
2,480
4,500
9,000
3000
760
2,480
2,480
2,480
4,500
9,000
3100
1,280
3,200
3,200
3,200
5,500
10,000
3200
3,400
1,560
1,560
1,560
2,500
7,000
3600
1,120
3,240
3,240
3,240
5,600
9,500
3700
480
1,520
1,520
1,520
3,500
6,000
3800
880
3,480
3,480
3,480
5,500
10,000
3900
560
1,960
1,960
1,960
4,000
8,000
4000
640
2,080
2,080
2,080
4,200
8,500
4100
1,280
2,600
2,600
2,600
4,000
11,000
4300
520
1,760
1,760
1,760
4,400
7,500
4500
440
1,760
1,760
1,760
3,800
7,500
4700
400
1,280
1,280
1,280
1,500
2,000
4800
440
1,560
1,560
1,560
3,500
7,000
5100
1,040
1,200
1,200
1,200
900
2,430
800
$
34
1958
1962
640
$ 1,480
$ 1,480
$ 1,480
$ 3,450
$ 7,500
6000
760
2,200
2,200
2,200
4,000
8,500
6400
800
1,640
1,640
1,640
3,000
6,500
1400
760
1,480
1,480
1,480
2,800
7,200
1500
760
1,480
1,480
1,480
2,800
3,000
1600
1,480
2,840
2,840
2,840
6,000
10,500
1700
760
2,200
2,200
2,200
4,000
8,000
1800
760
1,840
1,840
1,840
4,000
7,500
1900
880
2,160
2,160
2,160
4,300
9,000
2000
480
1,320
1,320
1,320
3,600
6,500
2100
560
1,480
1,480
1,480
3,000
9,000
2500
960
3,240
3,240
3,240
5,500
13,000
2600
560
1,480
1,480
1,480
3,800
9,000
2800
320
1,960
1,960
1,960
4,830
9,500
3100
680
2,280
2,280
3,800
6,200
11,000
1961
1965
1968
1970
Parcel No,
5200
$
1965
1969
1972
1976
Map 2 1E 11AC
Site 2 Regulated Parcels
Parcel No.
1957
1976
Map 2 1E 2BA
100
2,600
4,240
4,040
4,200
7,000
17,640
200
640
1,720
1,720
1,730
2,400
5,250
300
4,960
7,200
7,200
9,040
10,900
26,460
400
2,400
3,400
3,400
3,480
6,900
17,640
500
4,160
10,800
10,800
16,520
15,700
35,280
600
5,000
6,640
6,320
6,600
9,600
22,050
35
Parcel No.
1957
1961
1965
1968
1970
1976
700
$3,040
$ 4,360
$ 4,360
$ 4,560
$ 7,200
$19,840
800
8,720
7,920
7,520
7,900
10,500
23,150
900
8,640
8,200
7,360
8,200
9,800
23,150
1000
N/A
2,040
2,040
2,040
2,500
6,300
1100
N/A
3,280
3,280
3,280
3,500
4,200
1200
9,720
4,600
4,600
4,600
4,500
8,400
1300
5,120
8,120
7,720
7,720
11,600
24,250
1400
2,320
5,920
5,920
5,920
7,000
18,740
1500
2,320
5,800
5,800
5,800
7,000
18,740
1700
2,200
6,720
6,360
6,700
7,900
19,840
1800
2,720
6,960
6,640
7,000
8,100
19,840
1900
1,720
5,440
5,440
5,440
7,000
17,640
2000
1,200
1,640
1,080
1,700
4,000
7,710
2100
7,200
8,000
7,600
8,000
9,400
22,050
2200
6,000
8,040
7,680
8,100
8,800
22,050
2300
4,480
6,160
5,560
6,200
600
900
2400
1,360
1,760
1,680
1,800
4,000
7,710
2600
N/A
N/A
7,240
7,240
8,200
22,050
2700
6,800
7,520
400
400
600
1,570
100
5,760
5,600
5,600
5,600
10,200
20,940
200
2,520
3,000
3,000
3,240
5,900
14,330
300
3,880
840
840
840
2,760
9,450
400
2,880
1,120
1,120
1,120
4,000
7,710
500
N/A
N/A
2,200
2,200
4,000
8,400
600
3,800
4,560
2,480
2,480
7,000
12,120
Map 2 1E 2BC
36
Parcel No.
1961
1957
1965
1968
1970
1976
Map 2 1E 2BD
100
$4,960
200
5,800
$ 5,240
$ 5,800
$ 7,500
$17,640
3,760
3,800
3,040
3,800
6,000
15,430
300
7,840
7,360
5,880
9,860
10,700
23,150
400
6,800
7,640
6,160
N/A
N/A
22,050
500
7,840
8,840
7,080
8,900
9,700
23,150
600
6,400
7,400
5,920
9,860
10,700
22,050
700
7,120
8,120
6,480
8,100
9,350
19,840
$
Site 2 Unregulated Parcels
Map 2 IE 2BA
2800
N/A
3,240
3,240
3,240
4,400
13,230
2900
1,680
2,600
2,600
2,600
2,400
6,300
3000
2,800
4,040
4,040
4,040
6,800
15,430
3100
720
N/A
N/A
240
400
520
3200
2,000
6,320
6,320
6,320
9,100
17,640
3300
3,680
4,600
4,600
5,040
7,900
23,150
3400
2,000
4,400
4,400
4,520
9,000
18,740
3500
N/A
2,600
2,600
2,600
1,800
5,250
3600
640
800
800
800
1,200
2,100
3700
2,240
3,200
3,200
3,200
6,200
15,430
3800
1,560
1,720
1,720
1,720
2,600
3,670
3500
4,000
3,240
3,240
3,800
3,800
8,820
3600
2,640
2,200
2,200
2,200
3,000
7,350
3700
2,000
3,760
3,760
5,720
6,200
12,120
Map 2 1E 2BB
37
Parcel No.
1957
1961
1965
1968
1970
1976
Map 2 1E 2BC
700
$2,640
$ 2,720
$ 2,720
$ 2,720
$ 3,600
$ 7,160
800
4,200
3,760
3,760
3,760
4,000
7,710
900
4,720
5,120
5,120
5,120
6,600
12,120
APPENDIX C
INDIVIDUAL PARCEL APPRECIATION RATES
Site 1 Regulated Parcels
Parcel No.
1958-69
1962-72
1965-76
1972-76
1958-76
Map 2 1E 11BA
600
2,3287
927
2917,,
2247
6,7867
700
324
86
208
180
675
800
226
109
365
236
825
1900
250
112
330
206
825
2000
253
128
308
179
778
2100
236
119
340
200
802
2200
240
103
315
213
755
2300
260
114
272
167
708
4700
517
165
362
155
1,875
4800
334
127
292
161
975
4900
300
120
313
183
938
5000
297
109
306
196
907
5300
271
108
261
170
707
5400
305
111
271
171
827
5500
353
110
250
171
884
5600
3,150
181
377
146
11,875
5700
409
212
556
200
2,273
6000
1,800
224
509
157
9,167
6100
562
179
342
154
1,923
550
208
568
273
3,125
Map 2 lE 11BD
1600
39
Parcel No,
*
1958-69
1962-72
1965-76
1972-76
1958-76
1700
l,37l7
l957
4l77
2l37
5,7l47
1800
1,257
170
455
267
5,714
1900
640
195
417
213
2,667
2000
*
N/A'
227
519
229
N/A
2700
920
164
326
150
3,000
2800
313
241
500
156
1,563
2900
N/A
N/A
532
N/A
2,500
3000
567
189
529
225
3,000
3100
359
202
570
225
2,045
3200
186
219
1,442
536
2,679
3300
533
156
443
213
2,361
3400
957
208
485
186
4,643
3500
430
214
407
143
1,750
3700
620
150
430
229
2,667
3800
1,120
234
580
173
6,500
4200
460
209
471
159
2,167
4300
420
215
496
156
2,083
4400
308
114
295
181
909
4500
344
117
303
182
1,042
4600
258
103
253
183
65.5
4700
360
114
224
167
806
4800
303
119
239
171
726
4900
332
127
239
174
794
5000
334
123
242
167
806
5100
353
123
228
167
806
Not Available
40
Parcel No.
1958-69
1962-72
1965-76
1972-76
1958-76
5200
3947.,
1317
2O27
1547.,
7947,
5500
408
128
198
154
806
5600
408
133
198
148
806
5700
368
132
197
150
726
5800
395
166
256
155
1,012
6100
414
207
333
161
1,316
300
241
190
448
176
1,080
400
440
203
511
188
2,250
500
305
182
431
179
1,316
600
583
250
952
286
1,333
700
306
185
459
188
1,406
800
250
220
469
170
1,172
1100
405
162
308
190
1,250
1200
618
165
294
178
1,818
1300
470
133
319
240
1,500
1600
540
170
309
182
1,667
1700
447
164
328
200
1,471
1800
395
167
350
210
1,382
2100
459
173
260
150
1,193
2200
427
186
279
150
1,193
2300
405
162
265
164
1,071
2400
405
162
265
164
1,071
2500
373
132
216
148
806
2600
373
131
211
144
786
2700
374
131
211
144
786
Map 2 1E 11CA
41
Parcel No.
1958-69
1962-72
1965-76
1972-76
1958-76
2800
4l97
l207
3100
298
379
1,063
253
3,164
3300
237
145
311
193
737
3600
223
188
539
200
1,202
4000
251
159
412
207
1,036
4100
338
256
426
167
1,442
l927
l607
8067
Site 1 Unregulated Parcels
Map 2 1E 11BA
100
313
181
295
163
924
200
320
203
332
163
1,063
300
316
200
333
167
1,053
400
332
206
317
154
1,053
500
337
203
313
154
1,053
1100
N/A
195
427
219
N/A
1200
N/A
188
438
233
N/A
1300
550
182
398
219
2,188
1400
314
182
398
219
1,250
1500
286
188
438
233
1,250
1600
567
221
515
233
2,917
1700
133
N/A
N/A
600
1,250
1800
517
875
2,186
250
2,917
2600
273
173
427
184
1,167
2700
317
223
658
200
2,083
2800
317
223
724
220
2,292
3100
210
206
437
212
917
3300
375
200
354
177
1,328
42
Parcel No.
1958-69
3900
l397
ll57
2247,
l947
4000
400
181
296
164
1,184
4100
379
174
295
170
1,118
4500
278
160
283
177
787
4600
N/A
280
488
174
N/A
6300
680
187
367
179
2,500
6400
523
206
368
179
1,923
6500
465
184
332
181
1,544
6600
800
175
297
170
2,375
6700
750
187
333
179
2,500
6800
1,625
177
327
185
5,313
6900
1,625
66
308
462
5,000
100
963
146
260
178
2,500
200
800
196
357
182
2,857
600
267
194
531
274
1,417
700
167
290
850
293
1,417
800
583
625
1,181
189
1,771
900
158
N/A
N/A
264
1,771
1200
N/A
N/A
285
161
N/A
1300
N/A
N/A
285
161
N/A
1400
983
195
339
174
3,333
1500
500
192
333
174
1,667
100
875
2,125
243
2,125
1962-72
1965-76
1972-76
1958-76
6487.
Map 2 1E 11BD
Map 2 1E 11CA
100
43
Parcel No.
1958-69
1962-72
1965-76
1972-76
1958-76
Map 2 1E 11AB
800
3487
1547
3607
2337
900
258
169
363
214
938
1700
223
192
321
167
714
1800
273
192
375
196
1,023
1900
320
180
332
185
1,063
2000
186
235
342
145
635
2100
245
222
417
188
1,023
2200
255
214
402
188
1,023
2300
195
257
507
197
987
2800
202
140
309
220
625
2900
326
181
363
200
1,184
3000
326
181
363
200
1,184
3100
250
172
313
182
781
3200
46
160
449
280
206
3600
289
173
293
170
848
3700
317
230
395
171
1,250
3800
395
158
287
182
1,136
3900
350
204
408
200
1,429
4000
325
202
408
202
1,328
4100
203
154
423
275
859
4300
338
250
426
170
1,442
4500
400
216
426
197
1,704
4700
320
117
156
133
500
4800
355
224
449
200
1,591
5100
115
75
203
270
234
1,2507.
44
Parcel No.
1958-69
1962-72
1965-76
1972-76
1958-76
5200
2317
233L
5O77
2l77
1,1727.
6000
289
182
386
213
1,118
6400
205
183
396
217
813
1400
195
189
486
257
947
1500
195
189
203
107
395
1600
192
211
370
175
709
1700
289
182
364
200
1,053
1800
242
217
408
188
987
1900
245
199
417
209
1,023
2000
275
273
492
181
1,354
2100
264
203
608
300
1,607
2500
338
170
401
236
1,354
2600
264
257
608
237
1,607
2800
613
246
485
197
2,969
3100
559
272
482
177
1,618
1957-68
1961-70
1965-76
1970-76
1957-76
100
162
165
437
252
678
200
270
140
305
219
820
300
182
151
368
243
533
400
145
203
519
256
735
500
397
145
327
225
848
600
132
145
349
230
441
Map 2 1E 11AC
Site 2 Regulated Parcels
Parcel No.
Map 2 1E 2BA
45
Parcel No.
1957-68
1961-70
1965-76
1970-76
1957-76
1657,
4557,
276
6537.
91
133
308
220
265
900
950
120
315
236
268
1000
N/A
123
309
252
N/A
1100
N/A
107
128
120
N/A
1200
47
98
183
187
86
1300
151
143
314
209
474
1400
255
118
317
268
808
1500
250
121
323
268
808
1700
305
118
312
251
902
1800
257
116
299
245
729
1900
316
129
324
252
1,026
2000
142
244
714
193
643
2100
111
118
290
235
306
2200
135
109
287
251
368
2300
138
10
16
150
20
2400
132
227
459
193
567
2600
N/A
N/A
305
269
N/A
2700
6
8
393
262
23
100
97
182
374
205
364
200
129
197
478
243
569
300
22
329
1,125
342
244
400
39
357
687
193
267
500
N/A
N/A
382
210
N/A
600
65
154
489
173
319
700
l5O7
800
Map21E2BC
46
Parcel No.
1957-68
1961-70
100
ll77
l297
337%
235%
3567.
200
101
158
506
257
410
300
126
145
394
216
295
400
N/A
N/A
358
N/A
324
500
114
110
327
239
295
600
154
145
372
206
345
700
114
115
306
212
279
1965-76
1970-76
1957-76
Map 2 1E 2BD
Site 2 Unregulated Parcels
Map 2 1E 2BA
2800
N/A
136
408
301
N/A
2900
155
92
242
262
375
3000
144
168
382
227
551
3100
33
N/A
N/A
130
72
3200
316
144
279
194
882
3300
137
172
503
293
629
3400
226
205
426
208
937
3500
N/A
69
202
292
N/A
3600
125
150
263
175
328
3700
143
194
482
249
689
3800
110
151
213
141
235
3500
95
117
272
232
221
3600
83
136
334
245
278
3700
286
165
322
195
606
Map 2 1E 2BB
47
Parcel No.
1957-68
1961-70
1965-76
1970-76
1957-76
Map 2 1E 2BC
700
l037
800
900
l327
2637
l997
27l7
90
106
205
193
184
108
129
237
184
257
48
APPENDIX D
PARCEL INVENTORY FOR EACH SITE
Site 1.
(a)
parcels:
The breakdown of the parcels in this site is as follows:
Total number of parcels, including both FUD and non-FHD
325;
Kb)
number of parcels in the FHD:
(c)
number of parcels in the FHD omitted from consideration:
(d)
number of parcels in the FHD considered in study:
76;
(e)
number of parcels in the non-FHD portion of site:
197;
(f)
number of non-FHD parcels eliminated from consideration:
(g)
number of non-FHD parcels considered:
(h)
number of waterfront parcels:
128;
51.
52;
116;
81;
This includes 34 riverfront
parcels and 17 lakefront parcels on River Forest Lake;
(i)
number of parcels adjacent to the FHD boundary line:
39, which
includes 20 FHD parcels and 19 non-FHD parcels.
Site 2.
(a)
parcels:
The breakdown of the parcels in this site is as follows:
Total number of parcels, including both FHD and non-FHD
60;
Kb)
number of parcels in the FHD:
(c)
number of parcels omitted from consideration in the FHD:
(d)
number of parcels in the FHD considered:
(e)
number of parcels in the non-FHD portion of the site:
all 17 used in the study.
43;
5;
38;
17, with
49
APPENDIX E
DESCRIPTION OF STATISTICAL TESTS
Two variations of the statistical test for comparing two population
means were used to determine if there were significant differences
between the rates of lot value appreciation for the FHD and non-FHD
parcels.
One variation was used in each test where n values for both
means were at least 30, while the other was used in each test where the
n values for one or both means was less than 30.
The null and alternative hypotheses used for all the statistical
tests in this study were:
H:
The mean rate of lot value appreciation for FHD parcels is
equal to the mean rate of lot value appreciation for non-FHD parcels, or
FHD
Ha:
non-FHD = 0.
The means of the two groups of parcels (FHD and non-FHD) are
not equal, or
FHD
non-FHD
A rejection region of
= .05 (for two-tailed test) was used for
all tests.
Following are brief descriptions of each test.
(a)
The test for comparing two population means where n1 and
are equal to 30 or more.
Null Hypothesis (H):
(p
= 0 (i.e.,
l
Alternative Hypothesis (Ha):
l
Test statistics:
(for a two-tailed test).
X2
=J2
2
+
Vni
Rejection Region:
n2
Reject the null hypothesis if z is larger
than z12 or less than -z12,
Use s
to approximate
and s
and
respectively.
(b)
The t test for comparing two means where n1 and/or n2 is less
than 30.
Null Hypothesis (H0):
l
Alternative Hypothesis (Ha):
Test Statistic:
#
(for a two-tailed test).
sgl/n + 1/n
- 1)s
where s
\I
y
+ (n - 1)s
n+n-2
Reject the null hypothesis if t is greater
than ta or less than -.t, where a =
degrees of freedom0
u
X1 - X2
t=
Rejection Region:
= 0
-
/2 and t is based on (n + n - 2)
51
APPENDIX F
TEST RESULTS
Summary of Site 1 tests:
Comparison of All FHD Parcels to All Non-Fl-ID Parcels
1.
2.
1958-1969:
1962-1972:
z = -2.04
z =
3.52
Reject H
0
Reject 1-I
0
3.
1965-1976:
z =
1.48
Fail to reject H
4.
1972-1976:
z =
2.03
Reject H
1958-1976:
z = -1.76
5.
0
Fail to reject H
0
Comparison of FHD: Waterfront Only to All Non-Fl-ID Parcels
6.
7.
8.
1958-1969:
z = -1.61
1972-1976:
z =
1958-1976:
z = -1.40
2.47
Fail to reject H
Reject H
0
0
Fail to reject H
0
Comparison of FHD: Contiguous with FHD Line to
Non-Fl-ID: Contiguous with FHD Line
9.
10.
11.
1958-1969:
1972-1976:
1958-1976:
t = -.368
t =
.68
t =
.091
Fail to reject H
Fail to reject H
0
Fail to reject H
0
0
Summary of Site 2 tests:
Comparison of All FHD Parcels to All Non-FHD Parcels
1.
2.
3.
1957-1.968:
1961-1970:
1965-1976:
t =
t =
-
-
72
.35
t = -1.43
Fail to reject H
Fail to reject H
0
0
Fail to reject H
0
4.
1970-1976:
t = - .86
Fail to reject H
0
5.
1957-1976:
t =
-
.47
Fail to reject H
0