Volume Two 20. Open Space 4 Zone 20.3.3. Excavation or filling. 20.3.3.1. No excavation in excess of 1000m must occur on any land with a slope 3 greater than 20° within any 24 month period. 20.3.3.2. No filling in excess of 1000m must occur within any 24 month period. 3 20.3.3.3. Excavation or fill must not be in, or within 8m of, a Significant Wetland. 20.3.3.4. Excavation must not be within 8m of the landward toe of a stopbank and the depth of any excavation beyond that may not exceed 15% of the distance between the landward toe of the stopbank and the excavation. 20.3.3.5. Wheeled or tracked machinery must not be operated in or within 8m of a river (except an ephemeral river or intermittently flowing river, when not flowing), lake or Significant Wetland. 20.3.3.6. Batters must be designed to be stable and remain effective after completion of excavation. 20.3.3.7. Water control measures and sediment control measures must designed, constructed and maintained around all areas disturbed by excavation, such that the areas are stable and remain effective after completion of excavation or filling. 20.3.3.8. Excavation or filling must not cause any conspicuous change in the colour or visual clarity of a flowing river after reasonable mixing, or the water in a Significant Wetland as measured as follows: (a) hue must not be changed by more than 10 points on the Munsell scale; (b) the natural clarity must not be conspicuously changed due to sediment or sediment laden discharge originating from the excavation or filling site; (c) the change in reflectance must be <50%. 20.3.3.9. The diameter of any culvert used to drain any excavation or fill area must not be less than 300mm. 20.3.3.10. The fill must not contain any: (a) hazardous substances; (b) combustible or organic materials; (c) any other contaminant subject to chemical or biological breakdown; (d) liquids or sludge. 20.3.4. Planting of vegetation. 20.3.4.1. Only indigenous species must be planted in, or within, 8m of a Significant Wetland. 20.3.5. Vegetation Clearance. 20.3.5.1. Where clearance is by mechanical means, blading or root-raking by a bulldozer must not be used on slopes greater than 20°. 20.3.5.2. Woody vegetation must not be removed by fire or mechanical means within 8 metres of a river (except an ephemeral river) or lake. 20.3.5.3. In, or within 8m of, a Significant Wetland, Pest Plants identified in Appendix 25 and willow, blackberry, broom, gorse and old man’s beard must be the 20 – 3