Stormwater | Wai marakai

Services and activities

The stormwater group includes activities and services related to managing stormwater.

Stormwater is rainwater that flows across the ground and does not get absorbed into the soil. It flows into stormwater pipes and streams, and from there into the sea. The DCC owns and maintains a large network of pipes, pumping stations and other infrastructure to safely dispose of stormwater.

By ensuring adequate stormwater provision to Dunedin communities, we can protect public safety with a minimal impact on the environment.

Effective management of stormwater is essential to prevent the flooding of properties and businesses. Controls are also necessary to ensure that stormwater does not become excessively contaminated and cause pollution of the watercourses, the harbour and the ocean.

Community outcomes

The stormwater group contributes to the following community outcomes:

• A sustainable city with healthy and treasured natural environments
• A healthy city with reliable and quality water, wastewater and stormwater systems
• A supportive city with caring communities and a great quality of life

Significant negative effects:

The collection and disposal of stormwater may have potential negative effects on the interests of the community. The 3 Waters Strategic Direction Statement and the system planning approach prioritises and plans the resolution of these issues and recognises that some issues can only be resolved pragmatically over longer periods of time. The Otago Regional Council is the controlling authority for the streams. A high proportion of the runoff is from erosion of land in rural catchments.

• The local community can be affected by heavy rain events that result in flooding of properties and land.

Potential negative effects are managed as part of the day-to-day operation of the stormwater system (including planning for upcoming heavy rainfall events as part of the Civil Defence Response). Where flooding is due to the failure of stormwater pipes that are privately owned (watercourses), minor extensions to DCC’s network are made to reduce flooding and other hazards such as sinkholes and landslips.   Work is in progress to better understand secondary flow paths by reviewing updating and calibrating Stormwater Catchment Models.

• Flooding can impact on property values and could lead to a potential loss of businesses if repeated flooding impacts their ability to operate and/or insure.

Potential negative effects are managed as part of the day-to-day operation of the stormwater system (including planning for upcoming heavy rainfall events as part of the Civil Defence Response). Modelling of stormwater system to identify mains that are at capacity and may constrain future development.

• Discharge of contaminated stormwater to waterways.

Activities are permitted and regulated by conditions of relevant resource consents which ensure potential adverse effects are managed at acceptable levels. Water quality testing, and harbour sediment contaminant testing monitor contamination as part of resource consent requirements. Additional environmental monitoring project ongoing to sample critical stormwater outlets and assess environmental impacts as part of system planning.

• Discharge of stormwater into waterways or near areas of cultural significance.

Water quality testing and harbour sediment contaminant testing monitor contamination. Mana whenua are engaged as partners in system planning.

Still didn't find what you were looking for?