March 10, 2026
DRAINS Modelling for Stormwater Design: ARR 2019, OSD & Pipes
How DRAINS models stormwater quantity for NSW projects — hydrology vs hydraulics, ARR 2019 ensembles, OSD sizing and pipe network analysis.
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Updates from Contrive Consultants.
February 10, 2026
Stormwater Requirements Across Regional NSW: Builder’s Guide
How stormwater and OSD requirements differ across regional NSW councils — Shoalhaven, Wagga Wagga, Dubbo, Tamworth and Albury — and how builders…
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February 3, 2026
Small-Lot and Terrace Housing: Drainage for Compact Sydney Lots
Small-lot and terrace housing concentrates drainage risk. An engineer's guide to roof drainage, OSD, BASIX tanks and rear-lane lots on compact Sydney…
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January 13, 2026
Canterbury-Bankstown Stormwater & OSD Requirements Guide
Canterbury-Bankstown DCP 2023 stormwater and OSD requirements — what duplex and townhouse builders in Bankstown and Campsie need before lodging.
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September 9, 2025
Wollondilly Shire Stormwater Requirements for Builders
Wollondilly DCP 2016 stormwater and OSD requirements explained — Picton, Tahmoor and Wilton growth, rural-residential drainage and flood factors.
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August 12, 2025
City of Parramatta Stormwater & OSD Requirements Explained
City of Parramatta stormwater rules under DCP 2023 — OSD to the UPRCT handbook, drainage plans and WSUD for infill and high-density…
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May 6, 2025
Greenfield vs Infill Development in Sydney: Engineering Costs
Comparing greenfield and infill development in Sydney? A civil engineer breaks down the real cost drivers: earthworks, stormwater, services and approvals.
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March 25, 2025
Granny Flat Stormwater & Site Rules Across NSW Councils
How stormwater disposal, OSD and site rules affect granny flat approvals across NSW councils, and how to avoid the traps on downstream…
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March 11, 2025
Cumberland Council Stormwater & OSD Rules for Duplex Builds
Cumberland DCP 2021 stormwater and OSD requirements — a practical guide for duplex and townhouse builders in Merrylands, Granville and Guildford.
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March 4, 2025
NSW Low and Mid-Rise Reforms: Dual Occs and Terraces Expand
Stage 2 of the NSW low and mid-rise housing reforms commenced 28 February 2025. What the dual occupancy and terrace standards mean…
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