Broken Hill City Council – stormwater capture & reuse
Broken Hill City Council commissioned Darling Irrigation via a tender process to construct a Stormwater capture and re-use project at O’Neill Playing fields and AJ Keast Park. Both areas were traditionally irrigated with manually changed impact sprays, this was an inefficient use of water and very time consuming. It took about 10 hours per week voluntary labour to irrigate the fields. Darling Irrigation had 7 staff on site, over the period of 2 months (nearing completion) working 12 days on 4 days off due to the long distances involved. Local contractors were employed to complete electrical works, surveying works, pour concrete, cart spoil, and for wet hire of plant.
AJ Keast Park
This was a tight work site, in a built up area and high pedestrian traffic area. Aesthetics of the site were also important. For this reason , the stormwater captured is stored in an underground concrete load bearing tank, and lawn reinstated on top. Water is captured from a large Hill behind the Park, stored and then pumped through a KISSS irrigation system. The control room is located in an existing shed on site. The project leaves a tiny aesthetic, and environmental footprint and the green lawn area will be visually appealing with worlds best practice irrigation techniques.
AJ Keast Park Technical Information:
- Green area is approximately 4200m^2
- Grundfos APG.50 Sump pump delivering 2.5l/s @ 43m head
- Arkal Spin Klin M224 filter, 120 mesh
- Underground tank holds 120kl, probes set to hold approx 1/3 as town water supply
- 5300m of KISSS drip product delivering 1.6l/hr @ 0.5m
- Laterals are 0.8m apart
The System is controlled by Toro MM4000 Controller, with remote operation and fault functions. Seven capture stormwater and deliver to tank via 375RCP, and 300 PVC. Overflow is delivered into town drainage system
O’Neill Playing Fields
There are two full sized soccer Ovals and a small warm up area. In this location stormwater is captured from drains and passed through a wetland, then it is collected and pumped to above ground concrete storage tanks and via a KISSS irrigation system irrigates the playing fields, warm up area and spectator Hill. The existing water supply and fence was dismantled.
Technical Information for O’Neill Playing Fields:
- Area of site is 20,000m^2
- Water stored in 2 x 105kl above ground tanks
- Probes set to keep tank 1/3 full on town supply
- Water pressurised by CRN10-06 with VFD delivering 2.5l/s @ 38m
- Filtration via Arkal M224 Spin Klin 120 mesh
- System controlled by Toro MM4000 Controller, with remote operation and fault functions
- Approximately 25500m KISSS Drip product, 1.6l/h @ 0.5m
- Laterals are 0.8m apart
- 12 valves control the total area
Overview of Project
This project posed some challenges for Darling Irrigation with some difficulty in getting plant on site due to limitations with existing infrastructure, eg special ramps were required for concrete trucks. A 4T excavator was the maximum we could fit on site at AJ Keast to dig out the underground tank site, with benching this took 4 days.
Crossing and preserving existing services, water mains, utilities, optic fibre, constant difficulty in retrofitting sites and we were required to keep the water supply live for duration of the project.
Irrigating the spectator hill was also difficult due to slope on the site. Excavating and laying stormwater drainage lines proved challenging through a built up area and encountering rock.
Designed as a pilot scheme for the remainder of Broken Hill’s approximate 25 parks and ovals, the grand plan would save the City Council over 300Ml per year in an area where water is at a premium from both availability viewpoint and costs to service the city.