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City of Miami Beach
Water Main Breaks Analysis
Introduction
Cost by Neighborhood
The City of Miami Beach Public Works Department has been using Cityworks as its Asset Management System
since 2006. The application’s database contains the history of the past performed utility work. The Engineering
Division requested an analysis of the past water main breaks to determine the priorities for future restorations.
Neighborhoods are the administrative divisions used to assign
rehabilitation funding. For this analysis, the next step was to
compare work order cost, specific to water main repair, per
neighborhood. The cost distribution is showed in Map 3. In there,
the neighborhoods areas are displayed with different tones of
greens base on the count of breaks. The lighter colors correspond
to fewer breaks and the darker colors to more breaks. Looking at
the map is easy to realize that the neighborhoods with the largest
number of water main breaks are:
For many years, Cityworks software was only a desktop application. Although Cityworks is a GIS oriented
application, the Standalone version used by the City did not have a map and the users utilized the closest address
as the work order activity location. In 2011 the software was updated to the server version which works with ESRI
map services. That option allows the selection of the real location using GIS features, even though some users
continue typing addresses.
Significant effort was performed by CDM in 2006 to add the existing data into the GIS format. Nevertheless, the
GIS data for the utility system still has several years of backlog because the new data was not added. The
engineering and GIS Division are currently working together to bring the information up to date.
In regards to water main breaks, there are 714 Cityworks work orders. From that amount, only 206 are natural
breaks (i.e. spontaneous break). The remaining 508 work orders were generated after contractors unintentionally
damaged underground utilities. This information was selected using the associated Service Request which
differentiated one problem type from the other.
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13

Bayshore.
The next tier of neighborhoods with the greatest associated cost
ranging between $10,000 and $25,000 are:
Water Main Breaks Distribution During Time
54
Flamingo/Lummus.
To not surprise, the neighborhoods with the greatest number of
breaks also have the largest associated cost. That information is
represented in the map with graduated circle in red color.
According to the map, in both neighborhoods the City has spent
between $25,000 to $59,000 dollars in water main breaks repairs.
At the beginning of the analysis, the 206 natural water main breaks were added in ArcMap using a Query Layer.
The result was a point feature that later in the analysis, was used to select the closest main from the Water main
feature class. The attributes of those selected water mains were used in this study.
The first map, Map 1, was created with the simple purpose of
showing the location of the water main breaks. They were
differentiated by the year when the break occurred. The year with
the most breaks was 2009 with approximately 35% of the breaks,
followed by 2010, 2008 and 2006.


City Center.

South and Venetian Island.

North Shore.
2006
2008
2009
2010
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Hot Spot Analysis
Frequency for Main Material and Diameter
The second map was created to find clusters of the water main breaks. Using the Cityworks Query layer and the
tool for point density, a concentration layer was obtained. The result is displayed in Map 2. That information was
compared with other statistics for population density and business concentrations. The correlation by planning
districts is described below:
The size and material of existing water main were also considered
in this analysis. After selecting the water main using the Citywork
work order location point, Map 4 was created. It represents in
different lines and colors the size and the material of the pipes. It
also shows the frequency that the water main broke given those
attributes. That statistics (Graph 6), that excludes the unknown
data, shows that the major number of water main breaks has the
following characteristics:

South Beach: shows the major concentration of water main breaks. This is also the area with the greatest
population density and where most of the businesses are located.

Mid Beach: shows the lowest density of water main breaks. The population density of the area is low. There
is a business concentration area along W 41st Street where some water main breaks have occurred. Other water
main breaks clusters in this area are not related to the population or business location, like the breaks in Sunset
Island 1 and 2 or in the area for Alton Rd between W 45th Street to W 48th Street.

North Beach: displays water main breaks density in the northern area, where there is also a high population
density.

Material Cast Iron and diameter of 6”.

Cast Iron with 8”.

Ductile Iron for 12” and 8”.
The water main breaks selection data was compared with all the
water mains in the water system. The histograms in Graphs 6 and
Graph 7 show that the mains with major breaks are also the ones
more frequent in the Water main, which means that they are the
major number of main found in the City.
Age of Water Main
The City of Miami Beach has a total of 183 miles of water main pipes. Most of them, approximately 59 %, were
installed during the 1940s, 1950s or 1960s; therefore they are more than 50 years old.
The age is an important factor in the natural breaks. The most frequent years of installations, excluding the
unknown data, are:

1944-53 with 886 main, 18.96 %.
Map 4. Graph 6:
Water Main Breaks Diameter and Material Frequency
250
200
1954-43 with 872 main, 18.86 %
Frequency

From the past 20 years, there are 248 mains, which represent the 5.30 %.
150
100
50
Graph 1 of Map 5 illustrates the quantity of water main breaks base on the date of installation, material and
diameter of pipe. This histogram shows that the major numbers of water main breaks are associated with the
following characteristics:

1934-53 Cast Iron 6” with 47 breaks

2009 and 2011 Ductile Iron 8” with 57 breaks

2008 Ductile Iron 8” with 30 breaks.
0
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1
BRS BRS BRS BRS CI
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6
CI
CI
CI
CI
CI
CI
CI
CI
CI
CI
DI
DI
DI
DI
DI
DI
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GL GL GL GL GL UNK UNK UNK UNK UNK UNK UNK UNK
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6 -999 2
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Diameter for All Types of Materials
The newest pipes are considered replacement, because as it was explained before, the selection of the water
mains was done using a point layer created from Cityworks addresses. It is possible that after the break the main
was replaced.
The oldest group of years seems to be the one related to natural breaks. That is why in the map, it is shown the
location of the pipe with those characteristics and the other existing water mains that do not have break yet but
have the same attributes. They have been considered as future possible breaks locations.
Recommendations
The rehabilitation plan should include the following neighborhoods:
South Beach:

City Center.

Flamingo/Lummus.

West Avenue.
Middle Beach:

Bayshore.

Nautilus.
North Beach:

North Shore.

Biscayne Point.

Normandy Isle.
In addition, the plan should prioritize the replacement of the water main installed during the
period 1934-53 with Material Ductile Iron and Diameter of 8” which location was displayed
in Map 5.
The methodology used in this study should be used as a model for future analysis using
Cityworks data.
MIAMIBEACH
Author: Adriana Castro, GISP