Volume Two 2. General Rules 2.17. Standards that apply to specific permitted activities 2.17.1. Discharge of water to surface water. 2.17.1.1. The discharge must not cause erosion at, or downstream of, the discharge point. 2.17.1.2. The discharge must not alter the natural course of the receiving water. 2.17.1.3. The discharge must not cause flooding on land other than land within the Floodway Zone. 2.17.1.4. The discharge point and any associated structure must be maintained in a condition such that it is clear of debris and structurally sound. 2.17.1.5. After reasonable mixing, the discharge must not cause any conspicuous change in the colour or visual clarity of any waterbody, 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 discharge; (c) the change in reflectance must be <50%. 2.17.2. Discharge of an aquatic agrichemical into a waterbody. 2.17.2.1. Pest Plants identified in Appendix 25 and willow, blackberry, broom, gorse and old man’s beard are the only vegetation that may be sprayed. 2.17.2.2. The aquatic agrichemical must be approved for use under the Hazardous Substances and New Organisms Act 1996. 2.17.2.3. The application must be undertaken in accordance with the most recent product label. 2.17.2.4. The applicator must notify in writing details of the location, timing and agrichemical to be used in the application to: (a) every person taking water for domestic supply within 1km downstream of the proposed discharge; (b) every holder of a resource consent for the taking of water for water supply purposes within 1km downstream of the proposed discharge, at least one week before commencing the application. 2.17.3. Discharge of stormwater to water. 2.17.3.1. For stormwater sourced from land zoned Urban Residential 1, Urban Residential 2 (including Greenfields) or Urban Residential 3 in Blenheim, the maximum discharge must not exceed 20l/s. 2.17.3.2. For stormwater sourced from land zoned Coastal Living, the maximum discharge must not exceed 25l/s. 2.17.3.3. For stormwater sourced from land zoned Rural Living, the maximum discharge must not exceed 50l/s. 2.17.3.4. The discharge must not have, after reasonable mixing, any of the following effects on water quality: (a) the production of conspicuous oil or grease films, scums or foams, or floatable or suspended materials; (b) any conspicuous change in the colour or visual clarity; 2 – 23