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Column: Working around waterways

Published: 2018-03-19

Work in and around waterways can impact on bank stability, water quality and aquatic life. But there’s plenty farmers and their contractors can do to protect fresh water.

With the official start of autumn, now is the time for in-stream works. We’re keen to lift awareness of the issues involved and the responsibilities of farmers and others when carrying out works in and around water bodies. 

These works can include stream straightening and excavating the beds of rivers and lakes for a wide range of purposes, including to install bridges or culverts, remove a build-up of sediment or manage an unstable stream.

Sediment build up or instability may be caused by stock trampling the banks, or cultivation of paddocks too close to waterways without an adequate buffer zone or enough sediment control measures. It is important to ensure these causes are dealt with to avoid recurring problems.

The effects of such problems on aquatic life and water quality can be exacerbated through inappropriate in-stream excavations, or inappropriate removal of bank vegetation.

Besides hurting water quality and aquatic habitats through increased sedimentation, destabilisation of banks and beds can change the course of rivers and streams, resulting in loss of land and property and infrastructure damage.

Structures such as bridges, culverts and water intakes are essential features of most farms, but they must be well planned and constructed to ensure they are not at risk from the stream, and also to protect in-stream values. These structures can obstruct or divert flows, or obstruct fish passage up and down rivers, blocking access to spawning grounds and migration generally, including to areas that have been used as traditional or recreational fisheries.

Against that background, the Resource Management Act clearly prohibits any disturbances to river, stream and lake beds unless the disturbance is specifically allowed by a resource consent issued by a regional council.

That’s why our council policies cover the use, erection, reconstruction, placement, alteration, extension, removal or demolition of structures in, on, under or over the beds of rivers, streams and lakes and any disturbance of the bed as well, such as stream straightening or cleaning. To those planning such works, I suggest checking out the rules first.                                                                                                                                        

However, Waikato Regional Council also recognises there are a range of activities in and around waterways that are not harmful. The regional plan has many rules enabling “everyday” activities, provided certain conditions are followed to avoid the sorts of problems described above. Those rules identify what activities are permitted without consents, and the conditions those activities must meet.

All parties involved can be held responsible for unlawful in-stream works – from property owners and managers to earthworks contractors. So it’s important to check the regional rules and to seek good quality advice when planning any activity in or near a stream. That will ensure our rivers and streams are cared for as complex, delicate ecosystems in a productive agricultural landscape.

We all know farming depends on good quality water for stock and, generally speaking, better water quality means healthier animals and higher productivity.

Managing the margins of waterways – the so-called riparian zones – helps protect water quality on farmers’ own properties and those of their downstream colleagues.

Waikato Regional Council is organising a field day focusing on soil conservation and riparian management on 4 April 2018 at the Waitanguru Hall, RD1, Piopio. I suggest farmers and landowners take this opportunity to attend and listen to experts.

  • Bala Tikkisetty is a sustainable agriculture advisor at Waikato Regional Council. For more information contact him on 0800 800 401.