How much does a rainwater tank cost?

Saving is the key word for anyone who
builds or renovates. With a rainwater harvesting system, you
save on your water bill by using rainwater for the toilet,
the washing machine, the garden... How much does this system cost? We
put the question to Philippe Courcelle, advisor to water manager
GEP Watermanagement in Harelbeke. Prices quoted do not include
VAT. 

The
rainwater cistern

How big should
your rainwater tank be?
" In accordance with regulations, you'll need to calculate a requirement of 50 liters per
square metre of roof. For a 5,000-liter concrete cistern (the minimum mandatory
volume), you'll pay an average of 772 euros, while for a plastic
cistern, the average price is 1,650 euros" explains Philippe
Courcelle. 

The maximum authorized volume
is 10,000 liters. A 10 m³ concrete tank costs around 1,120 euros
and 2,360 euros if made of plastic. Prices exclude VAT and
transport, but include levelling and cover. "

Calculate the size
of the rainwater tank on the basis of 50 liters per square metre of roof.

"The choice of pump
depends on the type of house, the location of the cistern in relation to the house and
your own wishes," explains Philippe Courcelle. On average, a self-priming
pump costs 530 euros, and a submersible pump in the cistern costs
around 770 euros.

"The greater the distance to be covered and
the greater the number of connected devices, so the greater the need, the greater the
price. Would you like an automatic refill system for the
cistern with mains water when needed? Then you'll have to pay an additional 280 euros
for an additional pump system.

The filter

"In principle, a filter at
rainwater is the most important part of the system to prevent
leaves and clutter from finding their way to the bottom of the cistern. This
filter costs between 250 and 350 euros. 

"In addition, we always work with a
floating suction of 90 euros with self-priming pumps.
With submersible pumps, floating suction is included in the
price. A fine filter costs around 180 euros and will capture the last
particles present in the water."

The
switching system 

"Would you like
to switch automatically to mains water if the water level is
very low? This system doesn't fill the cistern with city water, but
has its own small cistern in the house, which is used for
current consumption" continues Philippe Courcelle. "You'll pay around 1,800 euros for
. 

"The choice of pump
depends on the type of house, the location of the tank in relation to the house and
your own wishes."

To commission a
rainwater harvesting system, the water supplier
must approve the system.

Installation costs
 

The costs of installing your
rainwater harvesting system are difficult to determine, as they depend on
everyone's situation. Whether it's a new build or
a renovation... Whether
the location is easily accessible or not... Whether a lot of excavation work
is required... In the case of renovation, costs are generally higher
since the installation requires the replacement of certain pipes and therefore
more demolition. Costs related to materials, such as pipes, are
limited. 

Mandatory
certificate

Before putting your system into operation, the
water supplier must check the system. Checking the indoor
system ensures that the quality of the drinking water is not affected by the
sanitary system in the house. The two must be kept strictly separate. The
price of this check depends on your municipality and water supplier.
It hovers around 130 euros.

Maintenance costs

"In principle, the
rainwater harvesting system doesn't require much maintenance, so
costs are limited. All you need to do is remove the sludge settled in the bottom
of the cistern and clean the filter 3 or 4 times a year, especially when
leaves fall and spring arrives."

At
final... 

For a rainwater harvesting system with a
concrete cistern, you'll pay between 2,000 and 4,650 euros. The price will vary
between 2,900 and 6,000 euros for a plastic cistern. Don't forget that
you still have to add VAT, transport and installation costs to the
invoice. 

Sources: EDITORIAL
LIVIOS 04-06-20