Storm Water Management through Water Sensitive Urban Design

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} a:link, span.MsoHyperlink {color:blue; text-decoration:underline; text-underline:single;} a:visited, span.MsoHyperlinkFollowed {color:purple; text-decoration:underline; text-underline:single;} /* Page Definitions */ @page {mso-footnote-numbering-restart:each-section;} @page Section1 {size:595.3pt 841.9pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:35.4pt; mso-footer-margin:35.4pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> As concern for environmental issues increases amongst the general population, most modern urban projects now include a Water Sensitive Urban Design (WSUD), which offers an alternative to the traditional conveyance approach to stormwater management. This is the case in the South East Queensland area where the parties involved in the latest fast urban development have made a real effort to include the program as a means of protecting environmental values in the region. It seeks to improve the ecological condition of urban streams, catchments and receiving waters through on-site reuse of the water in a sustainable manner as well as providing temporary storage. At this stage the effectiveness of WSUD treatment systems under real storm events is largely unknown due to insufficient data.

Campbell Scientific equipment has been involved in assessing the effectiveness of WSUD facilities in place at Coomera Waters on Queensland’s Gold Coast and predicting the quality of water exiting WSUD devices to the environment. The WSUD facilities include swales, a rain garden, a number of bio-retention basins and wetlands – all situated in an urban area. The key aim is to find reliable data justifying the efficiency of the WSUD stormwater system in place. Storm flow and rainfall measurements together with water samples taken at specific times throughout the flow period will allow researchers to compare water quality parameters such as nutrients, suspended sediment and heavy metal load at inlet and outlet points in these treatment systems.

To collect the data, water samplers, pressure transducers, flow velocity sensors, tipping bucket rain gauges and custom-designed, calibrated V-Notch weirs have been utilised. These sensors provide measurements of total discharge and flow rate at the weirs or creeks, water temperature, rainfall, suspended sediments and the amount of nutrients and metals in the water samples collected during flow periods. Campbell Scientific CR1000 and CR211 data loggers employed in this project use the Pakbus® communication protocol to communicate by three separate radio networks. The data routed from the CR211s to the CR1000s is then made available to a central PC via GSM modem connection.

Since its implementation, the system has been provided very promising results. Multiple samples and data have been collected and analysed - identifying the characteristics of the WSUD facility in place at Coomera Waters. As the overall impact of these development works will only be known after long term collection of data through many seasonal variations, study at this site will no doubt continue for some time to come.