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Keeping your wetland wet

Maintaining water levels is one of the most important tasks in managing your wetland. You may need a resource consent if you build a dam, weir or stopbank. Raupo, Lake Rotoroa

Before you even lift a spade, spend some time monitoring the source and amount of water, especially over a range of seasons. Mark out where the water comes to at different times of the year.

Restoring water levels

A wetland with a high water table or steady water supply will stay damp throughout most of the year. However, if the area has been drained you may need to restore the original water level by blocking a nearby ditch or drain.

Be aware that it is natural for some wetlands to dry out during the summer and that some species of fish and birds prefer it this way. Environment Waikato staff can help you with advice on restoring water levels.

In some instances, you may have to:

  • build a low bund (stopbank around a waterbody)
  • install a partially submerged weir
  • build a low dam across a stream or river (make sure fish can still get through) or
  • dig out an area to create a depression.

To make sure that water levels don’t rise unnaturally high these structures must allow for generous overflows.

A resource consent is required if your dam or diversion raises water levels on a neighbouring property or the impounded water is deeper than 1.5 m or over 1 ha in area. Earthworks within 10 metres of a flowing watercourse also require a consent. Check out our Proposed Regional Plan to find out more about when a resource consent is required for earthworks or vegetation clearance.

A dammed pond will diversify your wetland habitat for plants and animals. However they can be difficult to keep free of weed and algae in summer, and may block fish access.

Most native birds prefer swampy rushes, raupo or flax rather than deep open water. Make sure you provide wide areas of vegetation next to a pond.

Use this information to help you prepare your Wetland Plan.