Gawler Water Reuse Scheme

Adelaide, Australia—Honor Award, Commercial & Public Works

CONSULTANT:

John Gransbury
HydroPlan
Parkside, South Australia, Australia

 

PROJECT OVERVIEW:

The Gawler Water Reuse Scheme (GWRS) is located north of Adelaide in the State of South Australia.

The Gawler Water Reuse Scheme (GWRS) is a new water source for existing school sports fields, urban parks and 2,130 acres of vineyards in the Barossa Valley. In total, it supplies 1,300 ac-ft (1.6 billion liters), per annum, of recycled urban stormwater, harvested from the Gawler River.

 

PROJECT NARRATIVE:

The GWRS is comprised of 28 miles of pipeline from 18” to 4”, five pump stations, two tanks, several wells and two large dams. The primary 15” main lifts water up 660 feet over 17 miles from a 350 ac-ft storm water harvesting dam to a 550 ac-ft. elevated storage dam. This dam (named “Hill Dam”) was built on a crest in one of the vineyards where it can feed the others by gravity through 6 miles of 15” and 10” pipe.  The new scheme is fully integrated into the existing irrigation infrastructure.  The scheme has been designed for expansion when opportunities arise.

The Irrigation Consultant (IC) was the team leader responsible for engineering design, procurement, and construction management. Engagement in March 2015 was followed by sequential release of almost 100 work packages to fast track construction, manage risk and achieve best value. Completed in August 2016, on time and under budget, the GWRS is being hailed as an example of an effective public-private partnership. 

 

ROLE OF THE IRRIGATION CONSULTANT:

  • The IC’s firm was engaged by Bunyip Water in March 2015 for engineering design, procurement, and construction management
  • The IC became the lead designer, and the Superintendent of Works in “construct only” construction contracts
  • The IC reported to a Project Manager who was also engaged by Bunyip Water soon after it was formed to deliver the new water to its foundation customers
  • The IC was responsible for identifying and authorizing 98% of project expenditure on behalf of “the developer” (Bunyip Water), whilst meeting the funding objectives, transparency and contestability requirements of “the banker” (Australian and Local Governments)
  • The IC held weekly meetings of a Project Control Group (PCG) to report progress to the Project Manager and officers representing the developer and banker
  • The IC led the team that identified the scope of works, prepared drawings, and specifications, called tenders, negotiated contracts, raised purchase orders, inspected the works, and authorized invoices
  • The IC directly engaged some design specialists to supplement in-house resources, and engaged construction specialists on behalf of Bunyip Water

 

SPECIAL FACTORS:

The Gawler River is typically dry for 3 years in 10 so the GWRS includes Managed Aquifer Recharge (MAR) to provide buffer storage of up to 4,000 ac-ft.

Urbanization upstream has exacerbated flooding of the peri-urban landscape.

The GWRS also takes treated wastewater from the Virginia Pipeline Scheme (VPS), and a small quantity of (licensed) groundwater to create a new high-security water source of 2,400 ac-ft.

 

IMAGES:

To view project images, click HERE