Activities that alter the beds or banks of rivers and lakes, including tunnelling, drilling, excavation, reclamations or drainage, and deposition of substances can:
- create bank erosion or destabilise bed material which may result in:
- loss of adjacent land
- siltation of the waterway with consequent loss of aquatic and marine habitat
- accelerated infilling of wetlands and estuaries and harbours
- reduced opportunity for abstractive uses of water resource
- unintended changes in bed levels resulting in flooding
- increase in downstream channelisation and bank erosion, and undesirable oscillation of channel alignments
- damage to lawfully established structures
- adverse effects on the operation of drainage within drainage districts
- adverse effects on the structural integrity of river control scheme works,
- adversely affect the relationship tangata whenua as Kaitiaki have with their identified taonga such as waahi tapu, native flora and fauna and access to their customary fisheries, and
- adversely affect natural character of beds of rivers and lakes and their margins,
- Adversely affect existing legal public access to and along river and lake beds and their margins.
Deliberate introduction of any plant in, on, or under the beds or banks of rivers or lakes can:
- create plant pest infestation,
- obstruct the channel of a river resulting in increased flood levels on adjacent properties,
- redirect river flows resulting in localized erosion of river bed or bank, or on adjacent land,
- out compete desirable plant species* already present in areas adjacent to or downstream of the area into which the introduction is made.
The clearance of vegetation from the bed or bank of a river or lake can result in the adverse effects listed in Issue 1, and:
- reduced opportunity for downstream use of the water,
- redirection of the flow of water in a waterbody creating erosion,
- a rise in water temperature with a consequent loss of habitat for fresh water fish, creating a barrier to native fish passage, and increasing the potential for nutrients in waterways to create nuisance growth in waterways and estuaries.
Livestock access to the banks and rivers, lakes and wetlands1 that are areas of significant indigenous vegetation and/or significant habitats of indigenous fauna can
- damage aquatic habitat by browsing of desirable species, trampling and defecation
- create bank instability effects identified in Issue 1
- cause deposition of faecal material in a place where it can enter the water body causing adverse effects on water quality inconsistent with Chapter 3.1.