System design

Can a borehole and rainwater system work together?

Multiple sources can share storage and pumping — with the right controls, filtration and protection between them.

4 min read

Yes — and on many properties combining sources is the more sensible design. Rainwater is seasonal and limited by roof area; a borehole is more constant but depends on the aquifer and may need treatment. Together they complement each other, with municipal supply as the fallback.

How integration typically works

  • Each source has its own inlet and appropriate pre-filtration
  • Sources feed common storage, or dedicated tanks that are linked
  • Level controls and priority logic decide which source fills the tanks first
  • A single booster pump and pressure system serves the property
  • Non-return protection and correct separation prevent cross-contamination or backfeeding into the municipal supply

Water quality between sources

The sources have different characteristics, so filtration must suit the blend that ends up in storage — or each source is treated before it enters. Where potable use is intended, testing after integration is essential.

Practical priority logic

A common approach is to use rainwater first while it lasts, fall back to the borehole, and use municipal supply only when both are short. That sequence maximises use of the free source and reduces borehole running hours.

Design it as one system

Problems generally arise when sources are added one at a time without revisiting the whole design — mismatched pressure, tanks that never fill, pumps cycling against each other. An assessment covering all sources at once avoids that.

Discuss your water requirements

General guidance only takes you so far. Tell us about your property and we will advise on what applies to your situation.

Request a Consultation

Tell us about your property and water requirements and we will come back to you with the next step.

Your details are used only to respond to this enquiry and to advise on a suitable water solution. They are not sold or shared for unrelated marketing. See our Privacy Policy.

Get a Water Assessment