Rainwater harvesting

it is important to get clear the different between the rainwater harvesting tanks, detention tanks, storm-water tank and types of catchments.

I think that is why in sexy architecture coffee table books, the ground plane is always emphasised.
as this concerns also the larger mechanisms of rainwater systems if in place. Sensitivity to things is usually magnified a hundred fold, when the scale of the project is larger.

Also the sequence of flow ( this affects placement of tanks) and invert levels(lowest point of tank) required for gravity feed. Otherwise, a pump is needed which we usually try to avoid, as it brings about maintenance and a need to conceal it. the understanding is that it is common for private projects, but for public housing, reducing the need for maintenance is key. As we know maintenance is tied to town councils, which is tied to the ward, which is connected to the all mighty.

Note C&S scope of work, includes " hydrau;ic rqmts for rwht, n storage tank"

The issue here is when there are 2 separate rainwater catchments.
1) ABC bioswale ( direct discharge to external drains, so water can be " dirtier?"
2) Rainwater harvesting ( for watering of plants)

1)Catchments here are open deck of carparks, ponds, roof tops of commercial

Catchement--->ABC Bioswale---> Direct Discharge

2)Residential
 - the concern is that this catchment includes the resi corridor, and when washing, the soapy water/detergent also gets collected. This bets avoided. Although this being said, there is also a treatment room, attached to the harvesting tank?

Catchment---> Harvesting tank--->Detention Tank---> "Recycled Water" for watering plants

3)Stormwater tank ( required when there is a "basement")
pub code of practice (4.10.(b), requires stormwater tank n RWHT to be separate