Common
Problems

If you are finding your rainwater is leaving your tank with an unfavourable smell or the taste is off, you may find

Algae growth in tank.  Ensure tank is sealed to prevent sunlight entry. Reduce nutrient loads by using gutter mesh, rain heads, first flush diversion and tank screens. Chlorinate water (chlorine shock) to kill existing algae.

Dust and organic matter in the water from the roof.  Reduce organic matter and dust loads by using gutter mesh, rain heads, first flush diversion and tank screen.

Sediment at base of tank is re-suspended following rainfall.  Reducing organic matter and dust loads by using gutter mesh, rain heads, first flush diversion and tank screen will reduce the rate of sediment accumulation. Use of a calmed inlet will reduce the probability of re-suspension. Periodic removal of sediment is needed.

Animal in tank (frogs, birds, snakes, rodents).  Check and remove if present. Either discard water or sterilise via chlorine shocking. Ensure tank inlets (including manhole) and outlets are sealed to prevent.

You may have one or more of the following causing the issue

Algae growth in tank.  Ensure tank is sealed to prevent sunlight entry. Reduce nutrient loads by using gutter mesh, leaf and debris filters, first flush diversion and tank screens.

Dust and organic matter in the water from the roof.  Reduce organic matter and dust loads by using gutter mesh, rain heads, first flush diversion and tank screen.

Sediment at base of tank is re-suspended following rainfall.   Reducing organic matter and dust loads by using gutter mesh, rain heads, first flush diversion and tank screen will reduce the rate of sediment accumulation. Use of a calmed inlet will reduce the probability of re-suspension. Periodic removal of sediment is needed.

Animal in tank (frogs, birds, snakes, rodents).   Check and remove if present. Either discard water or sterilise via chlorine shocking. Ensure tank inlets (including manhole) and outlets are sealed to prevent.

You could have blockage in your system, or a leak. You may need to do a full review of your system and see where the water is being diverted before reaching your tank. This may be as far up the system as your gutters.

Overhanging vegetation or tall nearby vegetation depositing leaf and branch litter on the roof and in gutters – leading to blocked gutters and overflow during rainfall.

Trim overhanging vegetation. Consider installation of gutter mesh.

Gutters which have been installed according to AS/NZS 3500.1 are sized for one in twenty years peak rainfall intensity.  In rainfall events with rain heavier than this overflow may occur.

There could be a number of causes

a. Your tank screen is blocked with organic matter.   Trim overhanging vegetation. Consider installation of gutter mesh or install rain heads or at tank leaf filtration devices (Maelstrom filter).

b. Tank overflow outlet size is  smaller than the sum of the inflow pipelines.   Ensure overflow outlet size is at least as large as combined inflow pipelines.

c. Tank overflow screen is blocked.  Clean the mosquito screening – consider installing spring loaded screen for easy maintenance.

d. Tank overflow pipeline is blocked.  Check and remove blocking material – ensure exit end of pipeline has flap valve (aka. frog flap) to prevent animal entry.

For devices which have a diversion chamber this is normal as the device is designed to allow water to discharge from the chamber slowly – to reset the device for the next rainfall event.