Results - Water conservation measures in the Rotorua NOW Home®

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Problems with the monitoring

The water system and pump have been the cause of significant issues in the Rotorua NOW Home®. 

An electrical fault in the pump, which took 12 months to diagnose, affected the electrical systems in the house.  This severely interrupted water monitoring and resulted in little useable data. 

Flow rates in the system were excessively low at 1.6-1.8 litres/minute in the showers – a very poor shower for the tenants.  As the water system is a manifold system and is a relative newcomer to the market, it is not clear whether the system itself or the installation is the issue.

Overall water use

The Rotorua NOW Home® tenants used a total of 199 litres of water per person per day.  This compares to the Waitakere NOW Home® where the tenants used 189 litres per person per day in the first year, dropping to 172 litres per person per day in the second year. 

Of this water, 26% (51 litres) was supplied from mains water and 74% (148 litres) from the tank water.  This compares to the tank in the Waitakere NOW Home® which supplied 47% of the home’s water needs in year 1, and 52% in year 2.  The Waitakere tenants used only an average 100 litres of reticulated water per person per day in Year 1, dropping to 85 litres per person per day in Year 2.

Our analysis suggests that, although the Waitakere NOW Home® had a much larger tank, it did not have an automatic switch between tank and council supply, and relied on the tenants to manually operate a bypass valve to between mains water and tank water. Switching back to the tank water was often delayed until there was a large quantity of water in the rain tank and that the occupants had confidence that the tank water was not going to run out again.

Rotorua NOW Home

Rotorua NOW Home®