Porirua Pilot Project Background: Porirua WWTP consent to discharge treated wastewater and wet weather overflows/bypasses to the coast expires in 2020.  Increased frequency of bypass discharges during wet weather events. Need for GWRC to understand the issues impacting decision making around WWTP upgrades and consenting requirements was discussed with senior management WWL in November 2015.  Emerging regulatory framework i.e. PNRP Need to build relationships with WWL and key stakeholders PPP was created early 2016 using Twyfords ‘Power of Co’ model – a method for committing to work collaborating, co- designing and creating solutions together, having a shared long term vision and using an integrated option approach (i.e. assessing the network and treatment plant as a whole) Who’s involved: GWRC, PCC, WWL, Regional Public Health, Ngati Toa.  Wider public consultation to follow.

PPP covers both: Network overflows i.e. pump station discharges and popping manholes discharges to stormwater, freshwater and coastal environments; and Treatment plant discharges i.e. dry weather and wet weather discharges to the coast, including bypass (milliscreened-only) discharges and overflow (untreated) discharges. Refer: screenshot of WWL diagram showing known discharge locations in the Porirua catchment Source: WWL’s global stormwater consent application   WWTP discharge point

Where are we up to: workshops to look at long list options for network overflows and treatment plant/outfall upgrades. Short- listing options at present. Long list options include: Network - BAU, rapid treatment and discharge to harbour, greater conveyance to WWTP, storage to reduce peak flows and a cross-harbour pipeline, in differing combinations. WWTP - existing shoreline outfall, existing/higher standard of treatment, new location for shoreline outfall, new offshore ocean outfall, discharge to land, storage of peak flows and discharge on outgoing tides, in differing combinations. Next steps: Discuss preferred options with stakeholders, determine preferred solution, consenting requirements for various discharges. Key points: The PPP is to produce an integrated solution in an emerging regulatory framework Collaborative process to gain a better understanding of each other’s drivers and constraints (e.g. financial constraints) Shared long term vision for Porirua’s wastewater network that will result in improved environmental and public health outcomes Consents are only part of the solution/outcome – PPP is not just focussed on consenting, but the regulatory requirements provides a basis to build a broader conversation / process around it. Solutions may potentially be both regulatory (driven out of a consenting process), and non-regulatory (for instance network improvement strategies). PPP brings in key stakeholders into process early to co-define the problem, co-design the process to work through problems, and co-deliver the solutions – so it also becomes highly linked with a wider set of drivers (Iwi values, Whaitua processes, LTP planning priorities and the PNRP)