Concrete washdown is a necessary but often overlooked part of civil construction. Environmental expectations evolve and regulatory frameworks tighten, how we manage this byproduct is shifting from a back-of-mind task to a front-line compliance priority.
Concrete wash water discharge rules vary by council, based on their interpretation of the Resource Management Act 1991 (RMA) and regional plans. We’ve summarised key requirements for concrete wash water management across all regions. Including information from relevant regional plans. Be sure to check council websites for full details.
Each council name below is a clickable link that takes you directly to their website for easy access to detailed information. Please remember these are summaries only, and refer to official council sources for complete information.
Discharges to land or water (including concrete wash water) require resource consent unless explicitly permitted.
Concrete wash water must be fully contained and not enter stormwater systems or waterways.
Discharges of trade waste (including concrete wash water) must comply with the Regional Water Plan.
Discharges to land or water require resource consent under the Regional Freshwater Plan.
Enforces the RMA and regional plans through compliance monitoring and enforcement tools.
Discharges of contaminants (including concrete wash water) must be consented or permitted.
View the video. Watch Prime Fluid R&D Manager, Brent Petrie, put the system through its paces:
Discharges to land or water must avoid adverse effects and may require resource consent.
Concrete wash water must be contained or treated before discharge.
Under Plan Change 8, discharges of untreated wastewater (including concrete wash water) to land or water are prohibited without consent.
Concrete wash water must be contained and not discharged to water without consent.
Discharges to stormwater must be managed to avoid contamination.
Concrete wash water must not enter stormwater drains or natural waterways.
Operates under the Local Water Done Well framework, replacing the Three Waters Reform.
Environmental approvals for construction projects (e.g., Waitangi Wharf) are governed by the Chatham Islands Resource Management Documents.
On-site wastewater systems must comply with AS/NZS 1547:2012 and TP58.
While no specific guideline was found in this search, Nelson typically aligns with Tasman and Marlborough in applying RMA-based discharge rules.
Concrete wash water is considered a contaminant under the Tasman Resource Management Plan (TRMP).
With the Resource Management Act (RMA) set to be replaced by the Natural Environment Act and Planning Act in 2025, the way councils and contractors approach environmental compliance is undergoing a fundamental shift. These reforms are not just about broader environmental goals—they’re about how specific activities like concrete washdown are monitored, measured, and managed.
Regional councils are already stepping up enforcement. Otago Regional Council, for example, has issued clear warnings that even diluted concrete wash water is harmful and illegal to discharge into stormwater systems. Similar messaging is emerging from Environment Canterbury and others, with instant fines and prosecution now a real risk for non-compliance.
Concrete wash water is highly alkaline, often with a pH above 12.5. When discharged untreated, it can:
As councils prepare new Water Services Delivery Plans under the Local Water Done Well framework, expect more consistent monitoring, clearer discharge thresholds, and tighter controls on what leaves your site.
At Prime Fluid, we’ve worked closely with contractors and environmental advisors to understand the practical challenges of washdown compliance. The result is the Envirohub Concrete Washdown System—a modular, portable solution that recycles 100% of concrete wash water and makes compliance not just achievable, but efficient.
Whether you’re managing a major infrastructure build or advising on environmental management, Envirohub’s Concrete Washdown System gives you a measurable, auditable way to meet your obligations, without slowing down your site.
The shift in regulation isn’t about catching people out—it’s about raising the baseline. With national e-plans, centralised enforcement, and digital compliance tools on the horizon, the industry is moving toward real-time accountability.
For project managers, that means fewer grey areas. For environmental advisors, it means recommending solutions that are proven, portable, and practical.
🔍 Learn more about the Envirohub Concrete Washdown System:
Explore the Envirohub Concrete Washdown & pH Correction System