Sweet sweet stormwater
Written by Gary Walsh
For an environmental engineer there is nothing more beautiful than watching sparkling clean stormwater run out of a treatment system you've designed. I was lucky enough to experience that earlier this year when I visited the new bioretention system in Alma Park in the City of Port Phillip.
Contain your excitment....here it is:
Six months after the raingarden was planted, the plants are looking great. The inflow is straight off Dandenong Road, but the outflow is clear and the e-Coli is so low it almost doesn't need the UV disinfection.
City of Port Phillip was a great client that understands the effort needed to get the project right. Port Phillip made sure:
- Project budgeting was well informed
- There was good planning for feedback during design
- E2Designlab was deeply involved right through construction, commissioning and to provide training to those who will operate and maintain it.
The end result is fairly unique in having a high-spec monitoring and control system. This gives continuous live reporting of salinity, pH and turbidity in the stormwater drain, inflow and reuse flow rates and various water levels (including ponding within the raingarden).
The information being gathered is providing interesting insights into things like the characteristics of urban baseflow. This will shape future designs and add to confidence in these systems. It highlights how the health of plants is a key to the success of these systems, basically not too wet not too dry. Good design analysis sets you up for this, but in some cases the static system needs to be supplemented with intelligent controls to ensure it.