Stormwater

We can all play a role in protecting our waterways from contamination. Here are some simple things you can do to help improve water quality in Urban Environments.

• Wash your car on the grass – This allows the mud and contaminants to be filtered through the grass rather than washed directly into streams.
• Dispose of your water from washing your paint brushes via waste water service.
• Fix any oil leaks on your car as soon as possible, every drop can contaminate a waterway.

Applications

Please send your application form to water.services@selwyn.govt.nz

Stormwater Network

The stormwater services exists in our urban towns to manage run off from rainfall events. Schemes manage the run-off from roads, roof and hard-stand areas during rain events.

Stormwater is conveyed and ultimately discharged into the environment either to ground or to a surface water body. Discharges to ground mostly have soak pits, some schemes have large retention basins and first flush to treat stormwater and remove contaminants. Discharge to surface water includes open drains or streams. The method of disposal is depending on the ground conditions in the area (e.g., soils, history of surface ponding ext.) Details of the stormwater schemes are provided in the Activity Management Plan.

Every property within a township boundary and stormwater management area will pay the Stormwater service charge in their rates bill.

This charge allows for the management of stormwater which includes the infrastructure and facilities, networks operations contracts, and management of township stormwater consents.

Properties inside townships that require a private soakpit for stormwater disposal still have to pay the Stormwater service charge. This allows for the management and monitoring of the stormwater township consents allowing individual properties to discharge stormwater.

Our services

• The council is responsible for the stormwater system, which consists of drains, swales, pipes, soakholes and treatment devices (wetlands, basins and proprietary devices) that manage run off from roof and hard-stand areas.
• Stormwater is discharged either to ground or to surface water including open drains or streams depending on the ground conditions in the area.
• In newer parts of the District, where stormwater is discharged to surface water or near shallow groundwater, Environment Canterbury require stormwater to be treated.
• In the Selwyn district this is typically done using basins, wetlands and swales.
• In industrial areas or where there is less space, proprietary treatment devices can be used.
• Council engages contractors to manage the stormwater network.

Details of the stormwater schemes are provided in the Activity Management Plan .

The Stormwater and Drainage Bylaw 2018 [PDF, 425 KB] details activities permitted within a stormwater network.

Your responsibility

• Property owners are responsible installing and maintaining their soakpits. roof soakpits in line with section E1 of the building code, see Information for designers of stormwater systems . Please contact our Building Department to discuss requirements further.
• All culverts over open stormwater drains and swales are the responsibility of the landowner whose access is over the drain/swale. When they need to be replaced or maintained, it is the landowner's responsibility. Property owners must apply for a new entranceway crossing online as work on culverts must comply with Council's standard drawings for culverts over Council drains and swales.
• Mowing of roadside berms including swales is the responsibility of adjacent property owners. It is required that grass in swales be between 50mm and 150mm in length to provide adequate treatment of stormwater.
• Any construction or development site is responsible to manage sediment runoff, you can use the Environment Canterbury Erosion Sediment toolbox to help manage your site.
• Landowners are responsible to ensure vegetation adjacent to drains and swales does not obstruct the flow of water.

If you have a problem with the stormwater lateral on your own property, you should call a drain layer or drain cleaning company for assistance.

Applying for dewatering

• Any construction dewatering to the Selwyn District Council stormwater or drainage network requires pre-approval.
• Use the Water Discharge Application Form [PDF, 148 KB] to gain pre-approval.

• Note that Council resource consents exclude some high risk industrial and trade activities and property owners are required to obtain their own resource consent from Environment Canterbury. Global consents provides further information on our global stormwater consents.
• Use Ecan's Dewatering check sheet to assess your worksite or download the Builders Pocket Guide for more guidance

How you can help protecting our fish

Our drains are home to tuna, inanga and Canterbury mudfish. Stormwater drains in some parts of the District (e.g. Tai Tapu, Lincoln, Springston, Doyleston and Leeston) discharge into Council’s Land Drainage network and drain to Te Waihora (Lake Ellesmere).

Here are some tips to help protect our drains, our environment and local fish species:

• Sweep up garden waste from your driveway rather than washing it down the drain.
• Don’t let rubbish get into your drains, it could cause a blockage
• Dispose of all pet waste in your red bin.
• Use a car wash or wash your car on grassed areas
• Fix oil leaks in vehicles as soon as you can
• Don’t tip any waste paint, oil, antifreeze or chemicals go down the drain – take them to the transfer station for recycling or safe disposal. Household volumes of hazardous waste are accepted free of charge.

Integrated stormwater and land drainage planning

Stormwater and Land Drainage is managed locally in accordance with agreed Level of Service (LoS) as outlined in the Activity Management Plan (AcMP).

Selwyn District Council has begun developing Integrated Stormwater Management Plans (ISMP's) to better manage stormwater in terms of water quantity (the control of erosion and flooding) and water quality (minimising the effects of stormwater derived contamination on the environment).

Selwyn District Council has prepared an Integrated Stormwater Management Plan (ISMP) for Lincoln:

• Lincoln ISMP [PDF, 6238 KB]