Stormwater

Stormwater assets

Managing assets
Future spending and your say on it
- Future expenditure and costs of service
- How to have your say

Looking after the public stormwater system

The public stormwater network is operated and maintained by Metrowater, under contract to Auckland City. Metrowater is Auckland City's 100 per cent owned water supply and wastewater company.

The network includes:

1300km of pipes
29,524 manholes
six minor stormwater pumping stations
over 1000 stormwater outfalls.

The network needs looking after - pipes need to be repaired or replaced when they are broken, and kept clear of rubbish and dirt so that water can flow through them. Metrowater maintains the existing stormwater network, and improvements to the stormwater network are carried out by Auckland City.

Auckland City also works with Metrowater to find ways to make the system work better. It is our job to know where flooding is likely to happen in very heavy rain, and find ways to minimise it. Metrowater is currently managing a joint venture of stormwater and wastewater studies for Auckland City called the integrated catchment study.

Auckland City is your first point of contact for stormwater problems including blocked pipes, local flooding and contaminated waterways. Contact us if you are having this type of problem.

Asset values and costs

The estimated replacement cost of the city's publicly-owned stormwater asset is $449.75 million, with a further $93.74 million for the combined (stormwater and wastewater) system. Most of this value is pipes, with inlets, outlets, manholes, detention dams, pump stations, litter traps, lampholes and other items making up the balance.

Based on our assessment of the asset condition and useful life remaining in key assets (many of which are, fortunately, long-lived), Auckland City has an active inspection, maintenance and renewal programme that aims to manage risk and prioritise upgrades.

Things that help Auckland City identify flooding and pollution problems and put in place the best solutions include:

catchment management planning and integrated catchment studies
computer modelling to identify flood hazards and environmental effects and work out how engineering works can help overcome flooding and pollution
obtaining resource consents from the Auckland Regional Council for all proposed works that result in a new discharge to the environment (drainage improvements within the network generally do not require consent)
prioritising flooding mitigation projects according to the risk to residents and public health, and including estimated costs of new works each year in the Annual Plan
calling for competitive tenders by companies to do detailed engineering designs and for pre-qualified contractors to build the works to the designs
commissioning to make sure everything works before the project is handed over to Auckland City
operation, maintenance and monitoring.

Current expenditure

All stormwater services are paid for out of Auckland City's general rate, and each year cost around $40 million. These services include maintaining the network, improving current service levels by reducing flooding, mitigating pollution, and catering for future growth in the city.

Ratepayers also pay separate charges to Metrowater for water and wastewater. These payments cover usage of supplied water, and the maintenance and upkeep of the water and wastewater networks.

Stormwater asset management plan

Auckland City's visions and priorities are for environmental infrastructure that:

ensures a clean public environment and sustainability
provides a rapid response to stormwater problems such as flooding and pollution
maintains an effective stormwater system
protects flood-prone habitable buildings by reducing the number at risk from the 50-year storm

Auckland City's stormwater asset management plan spells out how this will be done, balancing community expectations, pressures of growth, environmental requirements and costs.

GIS-based asset records

Powerful software enables linking of different data sets to provide up-to-date and accurate information for managing Auckland City's stormwater assets. The GIS (geographic information system) contains aerial photos of all properties in the city, as well all legal property boundaries and plans of assets such as drains and roads.

Rating information and electronic reports related to development and consent proposals as well as any known flooding and other information can also be linked to each property. Another software programme automatically values pipes, manholes and other stormwater network assets, and this can in turn be linked to Auckland City's accounting software, enabling automatic updating of the values in the asset management plan.

Future expenditure and costs of service

Auckland City's capital expenditure (in dollar values as at 1 July 2003) over the next 20 years is projected to be $440 million for new works (mainly flood relief) and renewals (asset maintenance and repair).

The cost of the stormwater network will continue to be funded out of the general rate for 2004/2005. However, the Local Government (rating) Act 2002 now allows Auckland City to set targeted rates based on impervious area. The council is considering applying a new targeted rate in either 2005/2006 or 2006/2007.

How to have your say

There are many opportunities to have input to Auckland City's stormwater policies, including:

every year, by making submissions on the draft annual plan - which outlines how Auckland City collect and allocate money
district plan amendments
every three years, when long term community plan consultation is carried out.

The diagram below shows how these relate to each other:

Diagram showing our the annual plan, district plan, stormwater asset management plan, and long term community plan relate to each other.