Marlborough Sounds Resource Management Plan 26.1.6.1.6 Tree Planting For the purposes of edge protection and prevention of bank erosion, trees may be planted and maintained on river banks as a Permitted Activity provided that the following conditions are met: a) Crack willow shall not be planted along any river bank; and b) When layering is used as the principle means of propagation, trees layered along the bank edge shall be tied back with anchors. 26.1.6.1.7 Driving and Construction of Piled Retards Driving and construction of piled retards is a Permitted Activity provided that the following conditions are met: a) Piled retards may be used in conjunction with tree planting as bank edge protection on braided riverbeds; b) Piled retards shall only be used where there is adequate channel width and the retards are likely to aggrade with sediment to form a new river bank; and c) Piled retards may be used as debris arrestors in front of culverts provided that fish passage is not obstructed. 26.1.6.1.8 Repair of Culverts and Floodgates Culverts and floodgate structures may be repaired or reconstructed in their original location as a Permitted Activity provided that the following conditions are met: a) Provision for passage of fish at all tidal sites nominated by the Department of Conservation shall be made; and b) Any temporary coffer dams constructed must be removed at the completion of culvert maintenance. 26.1.6.1.9 Aquatic Weed Removal Aquatic weeds controlled by hand methods, or with the use of a floating mechanical weed cutter with a reciprocating cutter bar, or by excavator is a Permitted Activity provided that the following conditions are met: a) Cutting by mechanical means shall not be carried out more than once in any 12 month period on any river reach; and b) Mechanical cutting shall not be carried out over more than 90% of the channel width. An uncut strip shall be left on each side. Note: The removal of aquatic weeds by chemical means is a Discretionary Activity. 26.1.6.1.10 Gravel or Sediment Removal from Above River Water Level Gravel and other sediment extraction only within the riverbed is a Permitted Activity provided that the following conditions are met: a) Banks or adjacent land shall not be disturbed for gravel extraction; b) No refuelling or fuel storage shall take place in or within 20 metres of the riverbed; c) No gravel extraction plant shall be operated in flowing water; d) Gravel shall be extracted in strips and layers from the inside of bends, working from the water’s edge towards the land and with a perceptible slope rising away from the water’s edge; 26 - 10