Wetlands

Wetlands are important because they:

• work like sponges to store water and maintain water flow during dry periods
• work like kidneys by filtering out sediment and nutrients, improving water quality
• are host to a rich biodiversity, supporting many species of plants and animals that are found nowhere else. Native fish, such as the rare giant kōkopu, are nearly always only found in streams fed by wetlands. Fish abundance and diversity is almost always better in wetland-fed streams  

Many wetlands are:

• critical for maintaining water flow in streams in dry periods
• maintaining or improving water quality in our rivers
• habitat for many unique or rare plants and animals and more valuable ecosystem than beech forest because so much has been lost.
• a point of pride for many people who own them
• are helping to mitigate floods
• providing or improving amenity such as game bird hunting or landscape value
• adding value to properties and become assets to the landowner

 About 95% of wetlands on private land have been lost in Tasman.  This makes the remaining wetlands very valuable and something special.

• Further information on why are wetlands important

Wetlands are defined in the Resource Management Act and the Tasman Resource Management Plan as being permanently or intermittently wet areas, with shallow water and land-water margins that support a natural ecosystem of plants and animals that are adapted to wet conditions.

A wetland becomes dry land where the plant species typical of terrestrial environments cover over 80% of the area. Vegetation is used as it is an indicator of the hydrology of the site over a long period.

In its mapping, Council uses a list of wetland plants compiled by leading wetland ecologists and published by Landcare Research. 

• A vegetation tool for wetland delineation in New Zealand

The Resource Management Act (RMA) requires Council to include provisions for management of wetlands in the Tasman Resource Management Plan (TRMP). These provisions were introduced in 2001 and became operative in 2004.

The Tasman District Council is undertaking a project to identify and map all wetlands in the region as part of their requirements under the Resource Management Act. The mapping is initially based on information Council already has, such as aerial and satellite images, and then refined through site visits. This will improve the ability to make good land management decisions and help both landowners and Council to know more precisely where rules will apply.

Some commercial agreements rely on Councils to provide information. For example:

• Sustainable Dairying Accord requires fencing of significant wetlands and wetlands must be included in Riparian Management Plans (all dairy farms must have this by May 2020);
• Forest Stewardship Council certification requires proof that forests are managed in a sustainable fashion. This includes managing wetlands and other land of important biodiversity value.