Rainwater harvesting systems

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What is a rainwater harvesting system?

A rainwater harvester is the best way to collect, store and re-use rainwater for a wide variety of applications, from single dwellings to commercial and municipal projects.

They are ideal for the collection of rainwater or stormwater runoff from any roof type. Installed underground, they can easily be configured for home or garden use, giving you access to abundant and free rainwater for any application that doesn't require drinking water for use.

Rewatec rainwater harvesters are the sustainable solution of choice. They can reduce drinking water consumption by as much as 50%, whilst also allowing you to save up to 50% on your water bills.

Example applications

  • homes and residential developments
  • office buildings
  • industrial buildings
  • schools
  • hospitality sites
  • breweries and wineries


Why harvest rainwater?

The average person in Ireland uses 144 litres of water at home daily. This water is treated and distributed by costly municipal systems, and yet only a small fraction of it is used for functions that actually require potable water.

The scale of waste is enormous - and so is the opportunity it gives us to protect precious drinking water supplies by making better use of rain.

Pie chart Rainwater Harvester

Uses for rainwater

Harvested rainwater can be used in countless ways. Some of the more common uses include:

  • toilets and urinals
  • washing clothes
  • washing vehicles
  • watering and irrigation
  • filling pools and spas
  • cleaning roads and sidewalks
  • gardening
  • livestock


How do our rainwater harvesting systems work?


Rainwater is first collected by rain gutters (for sloped roofs) or a drain (for flat roofs). It then reaches a primary filter that prevents leaves, insects, and other debris from entering the system. Water that passes through the filter flows into a recovery tank.


Collected rainwater is stored in a leak-proof tank that is installed on the property or inside a building.

The tank is equipped with a circulation system that prevents water stagnation. During a downpour, this system evacuates liquid at the bottom of the tank to ensure that only the freshest water remains.

Rainwater use

Using harvested rainwater is simple. A specially designed pump directs stored water through a micro-filter that removes any small particles, then provides optimal pressure to supply appliances, plumbing fixtures, and building systems.

If no rainwater is available in the storage tank, all appliances are automatically and reliably supplied from the regular water system.

Maintenance for our rainwater harvesting systems

Rewatec rainwater harvesting systems are designed to operate reliably and autonomously for years. However, like all rainwater recovery systems, they require periodic maintenance to ensure high performance.

When Premier Tech visits your property to inspect your system, we will:

  • double check for cracks and leaks in the tank
  • clean filters
  • keep and update maintenance records for your system
  • explain any areas of concern and recommend next steps

We stand by our products

For over 50 years, we have proudly developed sustainable and long-lasting products that make a real difference for our customers, our professional partners, and, above all, our planet.

Our experience in the industry allows us to give you the following warranties for our rainwater harvesting systems:

  • Rewatec GRP rainwater harvesting systems: 20 years
  • Rewatec F-Line rainwater harvesting systems: 25 years
  • Parts warranty: 12 months

Visit our office

​​​​​​At Premier Tech we strive to fully meet the requirements of our professional partners. If you require product functionality guidance or more detailed information for installations, we can provide a solution to meet your needs.

Contact us to find out more

Rainwater harvester guides and manuals

Brochure for end users

Rewatec GRP rainwater harvesters

Installation guide (granular)

Installation guide (concrete)

Technical drawings

Available products

A full range of rainwater harvesting system sizes are available to suit all residential and commercial applications. These are based upon the garden/yard size, roof area and, if applicable, the number of people in the household or building (PE).


Rainwater falling on a concrete surface.

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