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

Step 1 - Excavation

Step 2 - Storage Tank Lining • Bentofix thermal lock geosynthetic clay liner overlayed 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