In November 2010, in partnership with Marrickville Council and enthusiastic local residents, Equatica built a small raingarden in a back yard in Dulwich Hill. Marrickville Council advertised and organised the project as part of their Environmental Workshop Series, which also includes "Water Sensitive Urban Design on Your Property" workshops. More information is on Marrickville Council's website. This page steps through the process with lots of pictures; it's intended as a basic guide for anyone interested in constructing their own backyard raingarden.

The first step was planning and design. David put together a brief document to illustrate the design:

Raingarden and rainwater tank design and analysis (PDF)

To complete the design, we also did some more detailed measurements on site. The plan was to divert water from an existing drainage pipe collecting water from the roof and driveway. We extended the drainage pipe by a few metres to direct water to the raingarden. Treated flows from the raingarden are infiltrated into the surrounding soil and in large events the raingarden overflows into an existing garden bed planted out with lily pillies.

Next Gayle spent a couple of weeks gathering all the materials and equipment we would need. We have put together a list of all the materials we used, along with approximate prices:

  • Recycled 100mm PVC pipe from Reverse Garbage at Addison Rd Community Centre
  • Fittings and glue (for the diversion) from a local plumbing shop approx. $50
  • 1 cubic metre of single washed sand from a local building supplier approx. $80
  • 30 native plants from Marrickville Council Native Nursery (species listed at the end)

The total cost for materials was approximately $200

We used simple household tools including a mattock, shovel, hacksaw, wheelbarrows, a crow bar and some hand tools. A tape measure and spirit level were also useful.

Construction started with the excavation of the trench to divert the roof water and driveway drainage into the raingarden.

At the same time we started to excavate a hole, 2 square metres in area and 600 mm deep, for the raingarden.

We carefully exposed the existing outlet for the stormwater drainage.

We connected new fittings to the outlet so that it could be extended into the raingarden.

Meanwhile we continued digging the hole for the raingarden.

After a while the excavation started to take shape - this photo shows the diversion trench (on the right) and the excavation of the raingarden (on the left).

Excavating the hole for the raingarden took the most time - mainly because it was slow going excavating in stiff clay. We used a mattock to break up the clay and then shoveled it out.

We connected the final pieces of the diversion pipe and cut the pipe.

Next we started filling the raingarden with the filter media - a single washed sand.

At the same time we started to backfill the trench over the diversion pipe...

...and relay the turf which we had stockpiled to place back on top of the diversion pipe.

We started to level off the filter media and prepare the raingarden for planting.

We placed sandstone pieces around the raingarden to provide a landscaped edge.

We also constructed a small stilling basin and rock scour pad at the inlet into the raingarden, using sandstone pieces.

Finished raingarden prior to planting.

We planted out the raingarden.

We flushed out the inlet pipe and tested the raingarden by pouring water down the pipe.

Finally we finished by watering the new plants.

Thanks to all who made it such a great day, with a special thanks to Gayle Adams and Jean Brennan.

Species used in the raingarden included:

  • Carex appressa
  • Dianella revoluta
  • Gahnia clarkei
  • Juncus usitatus
  • Persicaria decipiens
  • Viola hederacea
  • Alternanthera denticulata

This final picture shows the raingarden during its first rain event.