Rainwater Tanks - SES Building and Community Nursery

Synopsis

Frankston City Council recognises that local government is a large consumer of water resources with the ability to reduce consumption using innovative techniques. Frankston City Council is dedicated to demonstrating leadership in water conservation to the community. This will lead to further adoption of water conservation amongst the community. The Frankston SES (State Emergency Services) Building was identified as an ideal location for harvesting rainwater with tanks. The building is located next to the Council depot and community nursery. Collected rainwater is used for plant irrigation.

Benefits and Savings

Social benefits:

Education and leadership are provided to the community, encouraging water conservation and the adoption of water saving techniques.

Environmental benefits:

Water consumption is reduced by 350 – 400 Kls per annum. Erosion of local waterways is decreased with minimised stormwater discharge. The amount of peak flow events is reduced.

Financial savings for council:

Reduced potable water costs are paid back between 9 to 17.5 years.
Cost to council: $17,000

About the Project

The Frankston SES Building has a large (~500m2) roof catchment with a 45Kl holding tank. Runoff is collected through a manifold system from the building and directed into the holding tank within the community indigenous nursery. Collected water is gravity fed into two 680-litre slave tanks that then pump the water into the polyhouses and glasshouses.

These smaller tanks will draw automatically from mains water when their levels drop below 20 per cent. The irrigated polyhouses and glasshouses produce over 15000 tubestock per year. Propagated seedlings are used by local flora groups such at the Kananook Creek Association, and also fulfil Council’s landscaping needs.

South East Water Limited has provided past and present consumption data for the nursery. Operating savings from the reduction in consumption are being re-invested into the volunteer-managed community nursery and the Frankston SES Unit.

This project has received strong approval from the nursery volunteers and the Frankston SES Building. The project has also generated a high level of interest within the various business units of the Council and has been given full support from the Council Corporate Management Team.
The nursery is an excellent facility for educating visitors on water conservation practices and encouraging greater community participation in the retention and reuse of rainwater.

Future plans for Frankston City Council include retrofitting the tank systems in three child health centres, and introducing requirements for rainwater tanks to be installed in all new building projects.

Issues and Lessons Learnt

Community consultation with the nursery users group and the SES was an essential component to the success of this project.

Determining the location of the 45Kl rainwater tank was a sensitive issue as the chosen location was adjacent to some significant, large Banksia (Banksia integrifolia) plants.

The hydraulic calculations had to be accurate. Catchment area run-off versus estimated consumption patterns and modifying of the pumps to drive the irrigation from the slave tanks (distribution tanks) were important considerations in the project design.

Acknowledgements

This case study was prepared with assistance from Frankston City Council.