Bolton Reserve Stormwater Retention and Re-use System Innovative - - PowerPoint PPT Presentation

Bolton Reserve Stormwater Retention and Re-use System

Innovative Stormwater Harvesting Project!

Project Summary

• Stormwater harvesting system designed to

collect and store up to 7 million litres of stormwater per year

• Stormwater is diverted from the Council

underground drainage network. It is then treated and stored in underground storage tanks (1 million litre capacity) ready to be reused for:

– Flushing of toilets at the Box Hill City Oval – Irrigation of the Oval and surrounding reserve – Street cleansing, drain cleaning and plant watering via a hydrant and trucks

Project Details

• Project Team

– Project Management & Construction Supervision – City of Whitehorse – Detailed Design – Fisher & Fisher – Construction – Entracon Civil

• Project Budget

– $740,000 including $150,000 grant from the State Government’s Stormwater and Urban Water Conservation Fund

Project Objectives

• To treat and reuse stormwater to save

potable water

• To ensure the system is affordable and

easy to maintain

• To address under capacity in the

existing stormwater system

Innovative Design Elements

• The system diverts stormwater from underground

drains and treats the stormwater by passing through a CDS gross pollutant trap and a sand bio-retention system.

• The stormwater is stored in 4 underground tanks.
• The tanks comprise of excavations that are lined with a

geosynthetic clay liner and geofabric.

• The tanks are filled with scoria aggregate.
• The water is stored in the voids of the aggregate.
• The tanks are covered with a geofabric layer, sand, fill

material and topsoil.

• Electric pumps, water purity monitors , delivery piping

and other piping works are installed.

Site Location

Bolton Reserve prior to works commencing. Site is to be restored back to this condition upon completion. Site Location Bolton Reserve Box Hill City Oval

Step 1 - Excavation

Step 2 - Storage Tank Lining

• Bentofix thermal lock geosynthetic clay liner
• verlayed with geofabric and sand on the base

Step 3 - Filter Media

• Storage media 25mm scoria aggregate

Step 4 – Pit Installation

• Pump pits
• Access & sampling pits
• Gross pollutant trap
• Bio retention filter

Step 5 - Reinstatement

• Scoria covered with geofabric, sand, fill

material and then top soil and grass

Step 5 – Plumbing & Reticulation

• Pumps and reticulation pumps installed

Project Successes

• Communication and consultation with key stakeholders

during project development including maintenance personnel

• Open space is retained as the system is buried

underground and reinstated as parkland

• Savings in potable water of up to 7 million litres per

year giving Council the resources to use water during water restrictions

• Innovative cost effective design eliminating the need to

construct detailed and expensive structures

• Improves drainage capacity of network by providing

storage volume both underground and above ground