Central Coast Council Stormwater Requirements (DCP 2022)

One Coast, One DCP – and Plenty of Building

The Central Coast remains one of NSW’s busiest growth corridors. Apartment and mixed-use development continues in and around Gosford under the city-centre revitalisation push, greenfield estates keep expanding through Warnervale, Hamlyn Terrace and Woongarrah, and infill dual occupancies and townhouses are common across Wyong, Erina, Terrigal and Woy Woy. Sydney’s housing pressure continues to send buyers – and builders – up the M1.

Since the merger of Gosford and Wyong councils, the planning rulebook has been consolidated, and stormwater is one of the areas where the new framework is most distinctive.

The Planning Framework: Central Coast DCP 2022

The governing document is the Central Coast Development Control Plan 2022, the consolidated DCP that replaced the separate former Gosford and Wyong DCPs. For drainage, the key section is Chapter 3.1 – Floodplain Management and Water Cycle Management, which is built around Water Sensitive Urban Design (WSUD) and Integrated Water Cycle Management principles. Detailed engineering design is governed by Council’s Civil Works Specification, with which all development drainage must comply.

A signature feature of the Central Coast approach is its tiered system: smaller (Type 1) developments demonstrate compliance with the applicable stormwater targets through prescribed options, while larger (Type 2) developments must prepare and submit a detailed Water Cycle Management Plan (WCMP) with the DA. Which tier your project falls into should be confirmed against the current chapter.

What Is Typically Required

• Stormwater drainage plans showing collection, conveyance, detention and the lawful discharge point, designed to the Civil Works Specification.
• Detention and discharge control: post-development flows generally cannot exceed what the downstream system can accept, and development must not obstruct or divert overland flow arriving from upstream properties.
• WSUD / water quality measures: rainwater tanks, bioretention raingardens or treatment devices to meet stormwater quality targets – scaled up to a full WCMP strategy for larger projects.
• Flood compliance: Chapter 3.1 also carries the floodplain controls, so floor levels and flood storage rules can apply to low-lying sites.

Numeric targets and the Type 1/Type 2 thresholds change from time to time, so confirm current figures with Council or your engineer before lodging.

Local Factors: Lagoons, Lakes and Wetlands

The Central Coast drains almost entirely to sensitive, slow-flushing receiving waters: the Tuggerah Lakes system (Tuggerah Lake, Budgewoi Lake and Lake Munmorah), Brisbane Water, and a string of coastal lagoons such as Terrigal, Wamberal, Avoca and Cockrone. Nutrient and sediment loads from urban runoff are a long-running management challenge for these waterways, which is precisely why Council leans so heavily on WSUD and water quality targets.

In the Warnervale–Wyong growth corridor, much of the land is flat, low-lying and wetland-fringed, so flooding, high groundwater and drainage outfall capacity are routine design issues. Around Gosford and Woy Woy, foreshore flooding and tidal influence affect discharge design, while steeper hinterland blocks at Erina and Terrigal raise the more familiar issues of overland flow and downstream easements.

How Builders Should Prepare

• Establish early whether your project is Type 1 or Type 2 – a WCMP takes longer to prepare and should be commissioned at concept stage.
• Check flood, wetland and groundwater constraints before committing to floor levels and basement ideas, especially around Warnervale and the lakes.
• Allow space in the site layout for raingardens or tanks – retrofitting WSUD after architectural design is locked in causes delays.
• Design to the Civil Works Specification from the outset.
• Confirm current stormwater targets with Council rather than relying on pre-merger documents.

Stormwater Design for Central Coast Projects

Contrive Consultants prepares stormwater, OSD and water cycle management designs for builders and developers across the Central Coast Council area, from Gosford apartments to Warnervale subdivision lots. Explore our stormwater services or get in touch – call +61 497 848 111 or email info@contriveconsultants.com.au.