Equatica

In November 2009, Bushpockets, a local community group, with the generous assistance of Sydney Metro CMA (funding), Marrickville Council (coordination, machinery, labour and land owner) and Equatica, built a stormwater treatment swale to treat road runoff for a street in Marrickville. This page steps through the construction of the swale with lots of pictures; it's intended as a basic guide for anyone interested in constructing their own small treatment swale.

The plan for the swale was to divert water from the gutter on the road, into the swale, where water would be retained, filtered by the plants in the swale and allow some of the water to soak away into the soil. Excess flows would be returned to the gutter after being cleansed by the swale.

Some of the key features of the project include

Community driven and directed: volunteer initiated and enthusiasm combined with's Equatica design and construction expertise, Marrickville Council resources and construction experience and SMCMA backing and funding
Quick: one month from conception to completion of main works
Cost effective: More than $20,000 value delivered for $8,000 in funding.
Sustainable: 100% use of recycled and on-site materials, nothing brought onto or taken from site apart from plants, working with natural topography
Multi-purpose: biofiltration, aesthetic, habitat, community building

The first step was planning and design. Michael Easton had been thinking about constructing a swale on the site, pictured right, for a while. After fortuitously securing a large pile of sandstone rocks through Jamie Basnett, Michael contacted Equatica to help develop the designs. Michael, Alexa and David surveyed the site and David put together a basic design to document Michael's swale idea: Bush Pockets Swale Concept Design (PDF)
To help implement the design, we asked for some funding from the Sydney Metro CMA who responded with surpising speed. Marrickville Council came on board as a project partner and assisted greatly by providing a mini excavator and Hassan Iskander, the amazing operator, trucks to move the excavated material around the site, traffic control, insurance, and some essential bushcare equipment such as hats and vests. The afternoon before construction started we marked out the site with pink spray paint and some survey pegs.

Construction began on Friday morning with the help of Hassan Iskander from Marrickville Council, Michael Easton and Equatica. We began to excavate the swale, taking care not to damage an underground electical cable.
We realised that the spoil that we were creating was going to need a a small truck to relocate it on the site. Hassan made some phone calls....
...and that got construction going faster. With the use of David Cleary and his truck and Jamie with another mini-excavator we could move dirt faster. Just like playing with tonka trucks.
The excavation was under control which allowed us to catch up with Phill Birtles from the SMCMA.
Hassan was moving dirt from the swale into the truck to relocate further along the site
Great teamwork from Marrickville Council construction crew sees two mini-excavators filling the truck at once
Considering that the temperature was now in the low 30s and Hassan was feeling the heat it was time for a well earned water break.
It was now time for Michael and David to do some real work, and they begin to finesse the shape of the swale
Once we had got the basic shape of the swale right, we started to work on the outlet of the swale. We created the outlet by reusing the large sandstone blocks. We relaid the blocks on their side.
Hassan showed his great skill and dexterity with a mini excavator by picking these large blocks up with the bucket and placing them in the exact right spot so they would fit flush with the kerb and road.
We had also started to create the rock weirs in the swale using the sandstone that Bushpockets has secured.
Rocks were moved by hand and wheel barrow down into the swale.
At the end of the day on Friday, afer surviving the 30 degree temperatures and a day out from behind the desk we enjoyed some of Michael's fantastic home brew with just a hint of ginger from the last batch of ginger beer...
Bright and early on Saturday we started up on creating the inlet to the swale using the same technique as at the outlet.
Hassan makes it look incredibly easy as the blocks fit perfectly into place on the first attempt
We started moving more of the sandstone down to the site so we could...
...form the scour protection areas for the inlet and outlet of the swale.
Alexa is carefully placing rocks in the rockweir of the swale to ensure that all the blocks are interlocking and stable.
Scott scours the sandstone rock pile for the right size pieces...
Claire begins to undertake the planting of the swale with Gahnia and Juncus.
Planting of the swale continues...
The completed scour protection zone - the result of Martin's handywork. Note how the stones are placed neatly and all interlocking to create a smooth surface.
Planting of the edge adjacent to the swale begins using drought tolerant native grasses sourced from Strathfield Council nursery...
Lucy and Michael planting out the edge of the swale...
400 plants in all were planted on Saturday - a small portion of what will ultimately be planted on the site
The bushpocket crew hard at work...
...
A close up of the Poa (in virotubes)
Watering is undertaken at the Bushpockets site by reusing 2L milk bottles transported in milk crates
Alexa is filling in the gaps between the sandstone blocks to ensure a smooth finish with the road surface.
Planting and...
... more planting
A close up of the finished rock weir in the swale. Rock weirs are used to create changes in the gradient of the wetland without erosion. At the same time when carefully constructed they can provide a great visual element in the swale
Watering the plants.
Morning tea arrives - bikkies and juice courtesy of Laura and Liam...
Michael and Hassan discuss the earthworks that are required to create the path along the site...
Some of the materials we used to create the swale.
The inlet to the swale with scour pad and the first part of the swale after being planted out with the rock weir in the background
Michael and Martin start work on a small rockery as a feature for the site.
The rockery is coming together...
Alexa rakes out the surface of the swale preparing it for planting
After a long day of work on Saturday we start to begin to clean up the site
The inlet to the swale, with sandbag in place to allow the swale plants to establish.
The newly created (and only half complete) path with sandstone stepping stones.
The inlet to the swale with grasses and temporary sandbag for protection
After two days of hard work and after the assistance of many willing and helping hands this is where we got to...planting will continue over the coming months and we are currently trying to secure some recycled gravel or concrete to finish the path