Determining the effectiveness of best management practices to reduce nutrient flows in urban drains managed by the Water Corporation: Part 1 Water quality and water regime in Perth urban drains

[摘要] The efficiency of the best management practices (BMPs) to reduce nutrient concentrations and loads in Perth¿s urban main drains is poorly understood. Results from the other cities cannot be reliably extrapolated because of Perth¿s unusually sandy catchments and the major contribution of groundwater to the nutrient loads in the streams. The research project, funded by the Water Corporation and CSIRO Flagship Water for a Healthy Country, has been established to address the issues associated with the generation and transfer to surface water of nutrients in the selected catchments with the following objectives: 1.Define the existing water quality issues, including nutrient speciation, concentrations, and their relation to drainage hydrological characteristics;2.Define the relationship between water quality and land use, water management in the catchment, climate and opportunities for structural interventions; and3.Establish the requirements for BMPs which are most likely to address the issues identified and relevant technology (in-situ treatments) based upon Western Australian, national and international experience. The study region covered developed areas where urban main drains contribute to drainage discharge to the Swan and Canning rivers. Four drains were selected for a review of available information; these included the Bayswater, Mills Street, Bannister and Forrestdale main drains.The project brought together a large number of data sets characterising the individual catchments. These included geological, hydrogeological and hydrological information, current land use and some aspects of catchment development history, as well as the water quality data collected over the last two decades by Western Australian water authorities. The evaluation methods included spatial analysis and time series analysis as well as the analysis of the baseflow and storm flow. The emphasis was placed on identification of nutrient speciation in urban drains and their variation both seasonally and over the period of water quality monitoring. The nutrient forms considered included: ¿For Phosphorus (P): soluble reactive P (SRP), dissolved organic P (DOP) and particulate P (PP)¿For Nitrogen (N): ammonium-nitrogen (NH4-N), nitrate-nitrogen (NO3-N), dissolved organic N (DON) and particulate N (PN)¿For Organic carbon (C): dissolved organic carbon (DOC) and particulate organic carbon (POC) Over 120 published papers and reports were reviewed, summarising the current national and international knowledge on in-situ water quality control BMPs and their ability to attenuate various nutrient species and the associated limitations. It was demonstrated that no one single BMP provides treatment for all nutrient species potentially present in fresh surface waters. The review also provides information related to typical nutrient sources in the urban environment, nutrient concentrations associated with the identified nutrient sources, and the nutrient attenuation or enrichment processes related to the nutrient transfer from the sources to the surface water bodies.

[发布日期] 2010-03-07 [发布机构] CSIRO

[学科分类] 地球科学(综合)