Part I - Other Considerations - Richmond Valley Council

Richmond Valley Development Control Plan 2012I9.4. Water Quality Controls(1) PreambleThe increase in urbanisation leads to an increase in contaminant loading intowaterways. This increase results from wastewater discharge, urbanstormwater, erosion, loss of natural vegetative treatment systems, and wasteas a result of inefficient resource use.Unlike wastewater, urban stormwater has not historically been treated. Urbanstormwater contamination results from a number of processes including:‣ Increased stormwater volumes and subsequent increased Nitrogen andPhosphorous. This results due to increased impermeability, and the lossof vegetative and infiltration treatment mechanisms;‣ Oils, greases and heavy metals from roads and driveways;‣ Gross pollutants from leaf litter;‣ Sediment from construction practices;‣ Faecal contamination from sewer overflows and animals;‣ Chemical contamination from spills, household fertiliser and chemicalapplication, and inappropriate application rates;‣ Litter from irresponsible disposal practice.A decline in water quality may result in impacts such as:‣ A decline in the economic productivity of waterways. This includesfisheries and the suitability of water for stock, agriculture, domestic andindustrial uses;‣ Impacts on human health and subsequent lost productivity as a result ofincreased pathogen loading, creating conditions which promote harmfulmicro-organism growth (such as nutrient loading and cyano-prokaryotes)and pathogen longevity (such as turbidity);‣ Decline to the suitability of waterways for recreational contact andeconomic impacts as a result of illness, tourism reduction, aesthetics etc;‣ Ecological decline and decreases to biodiversity;‣ Creation of aquatic habitats which encourage invasive pest species.Source control measures, such as tanks and lot level infiltration devices,provide the most cost effective mechanism for reducing stormwater pollution.Stormwater Quality Improvement Devices (SQID) should be used after sourcecontrol methods to reduce the volumes and frequency of runoff generation,and subsequent pollutant transport, have been exhausted. SQIDs which areinappropriate for the location, budget and target pollutant can cause extrememaintenance, flooding, public safety and financial issues.(2) ObjectivesThe objectives of this element are to:‣ Protect the values and quality of receiving waters for human(commercial, recreational, aesthetic, public health) and ecologicalpurposes.‣ Promote and implement stormwater quality source control.Part I – Other Considerations – Water Sensitive Urban Design I.94