Urrbrae Wetland: In the Adelaide City region of South Australia
It is the pond you see on the cover of the Adelaide phone book, and a very suburban sketch of water it is, just off Cross Road in the bottom corner of the Urrbrae Agricultural High School Campus. It was dug to solve a problem that arose with a decent rain. One storm water pipe came down the hill from the suburb above the Water Research Paddocks, another brought the run off from Netherby and Springfield on the hills face, and they met here where there was only one inadequate pipe to take the storm water off towards the sea. Result? About once a year…..splash! Cross Road was flooded.
The three metre deep main L shaped pond now contains all but the worst downpours. After three days of showers, however Urrbrae Wetland Manager, Dr Allin Hodson, pointed out that the trash racks at the pipe exits had obviously overflowed and a lot of leaf debris from garden trees had flooded into the wetland. That was bad news, because that is one of the culprits that turned the old Patawalonga black and stinky.
“There’s no question these things can be enormously helpful”, Allin noted, “but when they were designed we didn’t know enough.”
The good news is that, seven winters on, the state government is funding extra shallow reed ponds and better catching gear on the uphill side to improve the incoming water quality. As Allin put it, we are still learning, and that is very much what the wetland is all about. In the Education Centre pine log building, East Adelaide School reception class was drilled on how not to carry a sampling net, before hunting parties were dispatched in search of pond life - bring ‘em back alive of course.
About 5000 students from primary to postgraduate and from across the state get wet and wise here each year in this giant hands-on wetland laboratory, and so do around 1200 adults in groups on Open Days.
“Oh look! Did you see that little creature run around?” enthused one five year old before they returned to the centre for some awesome viewing for researching how to store “polished “ stormwater in a fine sands aquifer as is found under the Urrbrae region, and in a substantial area of the Adelaide plain. The internationally recognized CSIRO water specialists are ready to tackle the questions … up the pipe of the Waite.
It is time we took our cue from the black ducks that appear so calm on the surface of the Urrbrae wetland. Perhaps we, too, should be paddling furiously.
At least for now, the story ends with a … at the exit grille here. 400 Olympic swimming pools worth of water go down the drain from here and out to sea each year. It’s cleaned up, and that’s a start, but it is still bad for the gulf and crazy for us. We are just beginning to understand through the education side of Urrbrae Wetland that the Murray crisis means we are not so far from ‘The Ancient Marines’ and his words, “Water, water everywhere, not any drop to drink.”
Instant reading showed the wetland water contained less than one third of the salt of the water. As our suburban roofs, roads and paved areas spread (even in established areas), the run off now roughly equals what Adelaide pumps from the Murray in a dry year.
“I would argue it is lovely stuff, and we are idiots to waste it. We really are,” enthused Allin. First, however, ponds like these need more help from us.
“It will have to be high quality water if we are to use it,” he said. “We need a public debate about it. Look at the oil coming in.” He pointed to an obvious rainbow slick spreading near the pipe. “Somebody has poured this down a street drain”.
He raised an important question. When we get our storm water act together, how do we store it?
“We think the best place is in an underground aquifer,” he offered, “So we can hold it there during winters, and then pump it through summer.”
That answer raises the need for urgent funding through the microscopes. Urrbrae Agricultural High School students are monitoring the sediment build-up and their practical research shows that the pond has lost up to a metre in depth because of mud and silt settling out from the discoloured flows clearly visible as they mixed with the rest. The soon-to-be-constructed settling ponds are keenly awaited by the former University lecturer - science educator - wetlands activist in charge here. Allin Hodson sees wetlands similar to this as a key to the future of Adelaide.
“I think we started out treating these as rubbish dumps, getting hold of the gunk in our storm water to protect the gulf, but now we are seeing their potential we water-harvesting machines for a very dry capital,” he observed.
That idea - that wetlands-treated water could help overcome Adelaide’s water shortage - suddenly has our attention. As Allin demonstrated, it certainly passes the salinity test.
Details:
Urrbrae Wetland
Manager, Dr Allin Hodson
Sn. Urrbrae Agricultural High School
505 Fullarton Road
Netherby, South Australia, 5062[NB Urrbrae Wetland entrance
via Gross Road, Netherby]School and adult group bookings
Ph: 8272 6010
Email: allin.hodson@bigpond.comFriends of Urrbrae Wetland
Open Day
Sun. 10 October 2003
2 pm - 4 pm
Donation $2
