Stormwater PNRP Implementation Kirsty van Reenen Senior Resource Advisor, GWRC

Stormwater from large sites Port Airport State Highways Large sites - Centreport: Resource consent application for stormwater discharges from log yard lodged. Requested further monitoring information then stormwater infrastructure significantly damaged by 2016 earthquake. Currently on hold. Wellington Airport: GW provided pre-application advice on information requirements for their application, in particular expectations relating to a draft monitoring plan. Draft application currently being prepared by the airport. NZTA – pre-application advice yet to be provided.

Stormwater from individual properties Stormwater from residential properties Stormwater from individual properties permitted (rule 48) subject to conditions One consent required and granted for private development. Consent requirement triggered because the stormwater discharge is from multiple properties (23 residential sites). Stormwater discharge is directly to Porirua Stream. Body corporate holds consent. Conditions of consent require: The installation of a detention tank and sumps to manage flows and separate solids and pollutants from stormwater The preparation and implementation of a maintenance plan for the stormwater detention device Discharge limit for suspended solids same as permitted limit Management of any erosion of the stream bank at the discharge location Monitoring of the quality of the discharge if requested by GW. - Discharge permit for this development unintended by PNRP. Proposed changes to rules will make stormwater from developments like this (up to 3000m2 earthworks) a permitted activity.

TA global stormwater consents Scope Information requirements Monitoring approach Consent conditions Consent applications received and currently being assessed for KCDC and Wellington Water (for Wellington, Porirua, Upper Hutt and Hutt cities). Significant pre-application advice and discussion during the consent process due to the extensive and complex nature of stormwater discharges. Scope Consents are for stormwater from the local authority stormwater network as defined in the PNRP. This includes devices specifically designed to capture, detain, treat, transport and discharge stormwater. These devices don’t flow at other times. While streams and rivers convey stormwater they do not have the sole purpose of functioning as a stormwater network so are not included in the definition and the global stormwater consent. WWL have requested that wastewater overflows be included in their global stormwater consent. PNRP. The approach we are taking is that wastewater overflows that enter the stormwater network from constructed or unconstructed overflows during heavy rainfall will be covered by the global stormwater consents. The TA will undertake monitoring during the 5 year period to identify the scale of the wastewater overflows and their effects. Wastewater overflows directly to streams or to the coast are not covered by these provisions and are subject to separate rules. Information requirements Details of current stormwater network and identify locations of wastewater overflows Details of the receiving environment – what values do these environments have? What monitoring information already exists to form an understanding of the effects of the discharges on the receiving environment? KCDC and WCC have done stormwater monitoring and have some existing information. Consultation AEE and gap analysis – what don’t we know about stormwater discharges and its effects, where are the gaps? Draft monitoring plan – based on the gap analysis and values of receiving waters what monitoring is proposed over the 5 year period? Monitoring approach KCDC and WWL have taken different approaches to developing their stormwater monitoring plan. KCDC commissioned their consultants who have been undertaking stormwater monitoring to date to undertake the gap analysis and put together a stormwater monitoring plan. GWRC will review this plan prior to approval/monitoring commencing. WWL engaged a technical advisory group to look at the existing information and develop a stormwater monitoring plan. (Dr Conwell will discuss this process further). Monitoring focuses on those things listed in policy 74 – aquatic ecosystem health and mahinga kai, contact recreation and maori customary use, significant values of the receiving environment. The consent will allow the monitoring plan to be flexible so that it is regularly reviewed and changed to ensure that robust information is collected over the consent duration to inform a longer term consent and a stormwater management strategy i.e. to fill all the gaps to establish a baseline. Consent conditions Conditions are currently draft. The condition set is short and focus on the monitoring plan. Conditions will require: The preparation and implementation of a stormwater monitoring plan. Includes monitoring objectives, locations, frequency, methodology, investigations into any issues identified, reporting requirements, and a review process for the monitoring plan. Requirement to manage the acute effects on human health identified during monitoring e.g. signage, further monitoring and investigation to identify cause and actions/projects to address the cause of the effects. Annual reporting to GWRC Provide input into a Regional Kaitiaki Monitoring Framework being developed by GW and its iwi partners The establishment of a stormwater working party (WWL only) to review monitoring results, advise on remediation actions to address acute effects on human health and advise on the development of a long term stormwater management strategy. Members are key stakeholder organisations such as iwi and Regional Public Health. The preparation of a draft Stormwater Management Strategy prior to expiry of consent in accordance with Schedule N of the PNRP e.g. a strategy to ensure water quality objectives/limits (maintain or improve) will be achieved through management and improvement to stormwater discharges.