providing a novel solution for monitoring water distribution
systems from space
by Utilis Corporation & SUEZ Advanced Solutions UK
screenshot shows the 100m radius that was targeted wherein
the leak was found to be right in the centre. The detected
leak that was later repaired
increasing pressure on water utilities to reduce their levels of
leakage. The man-hour effort required to find and locate leaks
only gets greater as network managers struggle to reduce leakage
to lower levels. Costs associated with the treatment and
distribution of water can be high and the penalties that
utilities can face for missing leakage reduction targets set by
Ofwat can also be high. Due to the rise in effort to prevent
water loss through leakages, utilities are compelled to explore
new methods of leak detection. One such method that some UK
companies are now trialling is satellite leak detection.
What is satellite leak
► Images are captured by
using an existing satellite that searches for water on other
planets. These images are then analysed by Utilis to detect
leaks in urban distribution systems.
► The satellite-based
methodology combined with onsite acoustic detection can
dramatically increase the efficiency in which leaks are found.
► No installation costs,
changes to existing infrastructure or capital expenditure are
required. The entire system can be surveyed several times a year
as opposed to just once every two to three years.
► The information can be
provided periodically, on a monthly, quarterly or half-year
basis and is presented on a graphic or tabular leakage report
containing the locations of suspected leaks.
► By using this
innovative method, utilities are quickly able to identify and
tend to emergent leaks within their networks.
How did it start?
The idea of using remote sensors to
find underground treated water started at the Hebrew University
of Jerusalem. An Israeli scientist was conducting research for
his thesis in geophysics and radiation transfers in the
atmosphere by using microwave technology to find underground
water on Venus and Mars.
As the technology showed indications
of water on other planets, it was soon discovered that there was
potential for locating water leaks on Earth, thereby helping to
reduce NRW around the world. With its many successes, the
technology continues to grow and currently has partners in 25
How it works
Images are acquired from
a low orbit satellite that revisits the same points on earth
every two weeks for recurrent analysis. Equipped with
airborne-mounted sensors, the satellite is at an altitude where
it can capture 3,500km3 of imagery. By overlaying
identified leaks on a map together with streets, pipes and leak
size information, the resulting technology can cover thousands
of square kilometres.
The satellite mounted
synthetic aperture radar (SAR) sensor works by sending
electromagnetic waves to earth and back to the satellite.
Depending on what was penetrated, above or below ground, the
returning waves have a wide range of spectral signatures.
Detecting leaks in urban distribution pipes is dependent on the
focus of spectral signatures that looks for potable water and
works to filter out non-potable water sources.
Once the wave touches or
penetrates the ground, data is sent back to the satellite which
then scours the spectral signature that holds all emittance of
material with respect to a wavelength. The satellite then looks
for the signature of treated water that has been lost. The
signature then helps to reduce false readings of already treated
water such as fountains, pools, lawn watering etc.
This reading shows the reduction in minimum nightline
after the identified leak had been repaired
Click to enlarge
Once the image is
received, it undergoes a three-step process before delivery to
the client. The first step requires no field works and instead
focuses on collecting data for actual locations on Earth to
In the second step,
signals returns are filtered from common objects such as
buildings, cars and vegetation that one can expect to find in
dense and complicated urban environments. It is at this stage
that utility pipe layers are applied as it is assumed that at
this depth, treated water can only come from pipes, however,
other possibilities are not discarded.
In the third step,
algorithm analysis detects treated water by looking for a
particular spectral signature that is common to drinking water.
The user is then presented with a graphic report overlaid on a
map with streets and pipes that show the areas of interest.
Previous testing has shown that varying water types might appear
differently to the waves and made identifying the true
signatures of treated water a crucial step. The technology now
eliminates water sources such as oceans, rivers, water tables
The end result is the
simplest output imaginable - locations of potential leaks
throughout the monitored area.
Locating leaks on the
Once the process is
finished, the client will receive the data in the shape of a
keyhole markup language (KML) format. This ensures the data can
be added to their GIS systems, web or mobile applications, Excel
and leak sheet and can then be used when carrying out field
The leaks are assigned according to the probability and are
divided into a four-colour category: blue, green, yellow and
red. Blue represents the lowest probability of a leak and red
signifies the highest probability of a leak.
Yorkshire Water trials
In the UK, the technology
is currently being trialled with Yorkshire Water as they explore
ways to reduce leaks in their network. One set of results showed
a 100 metre radius having five areas of interest that were
identified as having potential leaks. Of the five areas, one
resulted in a leak on an old clamp that was quickly located and
Experienced leakage inspectors stand by the located area
marked for repair.
Eddy Segal of Utilis (center left) and Nick Haskins of
SUEZ Advanced Solutions (center right).
Benefits of satellite
Some benefits of the
► No preparations or
► Lower operational
► Increased efficacy of
► Surveying of entire
systems up to six times a year.
► Routing to leaks
through geographic clusters.
► Priority leaks can be
targeted quickly reducing potential damage and claims
Every water distribution system
experiences leaks. The effort required to determine where
the leaks originate from is greatly decreased with
technologies like satellite leak detection which can help
utilities to better manage their overall systems.
about satellite leak detection can be found at: