OSD Volume & Cost Calculator

OSD Volume and Cost Calculator

Enter your lot size and your consent authority. This returns the detention volume your council’s Site Storage Requirement implies, the number of crate modules and 40HQ containers that volume represents, and the two cost inputs that can be sourced publicly. It does not return a supply price — see the note at the bottom for why.

Consent authority SSR and PSD are read from that authority’s published DCP or policy.

Site area The area your council applies the SSR to. Read the DCP: some size on impervious area, not total lot area.

— required detention volume

Site storage requirement applied—: —
Permissible site dischargeThe orifice is sized to this. Your engineer sets the final diameter.: —
Storm Manage crate modulesAt 0.24 m³ of usable detention storage per module.: —
40HQ containersAt up to 330 m³ of installed storage per container, optimised stacking.: —
Excavation, NSWA$70–200 per m³ — a published range, not a quote. Soil, groundwater and pit location move it.: —
Ocean freight to an Australian portUSD $4.50–6.40 per m³ of installed storage, derived from USD $1,500–2,100 per 40HQ.: —
Crate supply priceMoves with load class, volume and accessories. We do not publish a number we would have to withdraw.: Contact for quote

Send your DCP — we return volume and orifice rate in 24 hours → Or download the OSD Sizing and Cost Worksheet (PDF) →

What this is, and what it is not. This is an order-of-magnitude check you can run before you engage a hydraulic engineer, built from each authority’s published SSR and PSD. It is not a design. Only a suitably qualified engineer can certify the storage volume, the orifice diameter and the structural adequacy of the system for your site, and every council listed here requires that certification.

Where the ranges come from. Where a council publishes a band rather than a single SSR, this tool shows the band. The excavation and freight figures are the only two cost inputs on this page that can be sourced independently; everything else on a real OSD budget — the discharge control pit, service relocation, rock, dewatering — is site-specific and is why two identical tanks 400 m apart do not cost the same.