Reviewof Artificial Destratification of Water Storages in Australia

ReportNo WSAA 9

December 1989

SYNOPSIS

Thisreport aims to review the current status of reservoir destratification inAustralia, focusing on the effectiveness of artificial destratification incontrolling biological and chemical aspects of water quality. The reviewpresents information and comment from relevant literature as well as thatobtained by discussion with persons responsible for Australian destratificationapplications.

Over fiftydestratification applications have been examined in detail and are presented ascase studies. The results of these applications are also examined inconjunction with discussions on the aquatic processes operating in stratifiedand destratified systems. The ways in which artificial destratification may actto alleviate water quality difficulties are discussed in the context of theAustralian experience.

It isconcluded that for the most part Australian destratification applications havebeen of limited success. The applications succeeded typically in attempts toalleviate problems associated with colour and turbidity and to a lesser degreeproblems associated with iron and manganese. It is in the area of algae controlthat destratification applications have been least successful, this reportfound that 68% of applications attempting to reduce and control algae levelsfailed to do so. The authors conclude that the relationships between mixing andalgae responses are areas requiring the most urgent attention.

Thisreport is the first part of a two-stage project and includes informationexplaining the principles of destratification as a water quality managementtool. The second stage of this project, currently under way, involves field andexperimental work on the effect of destratification on water quality in theHarding Reservoir in Western Australia. Both stages involve complementaryhydrodynamic field and modelling studies of destratification. These latterstudies, undertaken by the Centre for Water Research (The University of WesternAustralia) will be reported separately by the Urban Water Research Associationof Australia.

Copiesof the Report are available from WSAA, price $A50. Orders may be placed throughthe Bookshop at www.wsaa.asn.au or by email to info@wsaa.asn.au.