Are overflow pipes always needed ?
If a conventional rainwater harvesting system diverts additional downpipes that cause the inflow capacity to exceed the tank’s overflow capacity, the tank will overtop during heavy rain.
Eaves gutter and downpipe size requirements are calculated by a formula based on a regions 1:20 Average Recurrence Interval (ARI) as detailed in AS/NZS 3500.3:2003. Calculations are based on a 5 minute rainfall intensity.
No similar regulations exist for water tank overflow pipes.
Most States have poor water tank overflow pipe regulations and many “regulations” are in fact non mandatory guidelines.
The diverting of additional downpipes to a tank often contravenes any plumbing regulations that state that the downpipe’s inflow capacity must not exceed the tank’s overflow capacity or words to that effect but few persons know how to calculate this. Overflowing tanks can cause property damage and annoyance to neighbours.
Regulations or guidelines stating that overflow pipe must be the same size as the inflow pipe do not account for wet system infeed pipes that may be supplied by multiple downpipes
The harvesting of additional downpipes by SUPADIVERTAS through a tank’s bottom inlet has little effect on the tank’s overflow capacity.
When SUPADIVERTAS are height adjusted so that the top of their reservoir walls are below the bottom of the tank’s overflow, the overflow pipe is not needed provided no other downpipes drain to the tank’s top inlet.
Stopping diversion once the tank fills also minimises tank sediment build up. Continuous sediment transfer is a failing of conventional rainwater harvesting systems that continue to divert water after the tank fills.
Supadiverta eliminates ugly archways, downpipes diverted along walls and overflow pipes. Many householders do not install tanks due to costly and ugly plumbing.
With SUPADIVERTA, this is no longer an issue.
HANDY HINT IF FITTING AN OVERFLOW PIPE:
A thin organic film often develops on the surface of tank water. When the tank fills, the film often leaves deposits as water passes through the overflow mesh to storm water. These deposits can eventually restrict or block the flow of water.
Many tanks are ordered with the overflow outlet fitted away from the tank’s top meshed inlet and this is particularly common with slimline and oval tanks. The overflow mesh should always be easily accessible from the top inlet for cleaning.
When Supadiverta is height adjusted with the top of the reservoir wall below the bottom of the tank’s overflow, the overflow pipe is not needed provided no other downpipes drain to the tank’s top inlet.
Ugly archways, downpipes diverted along walls and overflow pipes are eliminated.
Subject to the fall of the land, tanks can be located away from the house without the expense of having the overflow pipe plumbed back to storm water.
Automatically stopping diversion when the tank fills minimises tank sediment build up. Continuous sediment transfer is a failing of conventional rainwater harvesting systems that continue to divert water even when the tank is full.
Any number of downpipes can be harvested by this method