Clarence floodplain project

The 'Clarence Floodplain Project' was established with the aim of improving the environmental management of Council's flood mitigation infrastructure and addressing some of the past impacts of flood mitigation on floodplain ecosystems.

Click here to read the latest Clarence Floodplain Project newsletters and publications

Background

The 'Clarence Floodplain Project' was established in 1997 with the aim of improving the environmental management of Council's flood mitigation infrastructure and addressing some of the past impacts of flood mitigation on floodplain ecosystems.

Flood mitigation works have been carried out for over a century on the Clarence, particularly in the 1960s and 1970s. Over the years many extensive drainage systems and hundreds of floodgates and other structures have been constructed. Their purpose is to provide protection from floods in both urban and rural areas. Better drainage has also increased agricultural productivity on the floodplain.

Flood mitigation has had some adverse impacts on coastal floodplains. A combination of drainage and blockage of natural creek systems has often led to poor water quality, fish kills, and reduced habitat for fish and other aquatic species. In some areas over-drainage has resulted in acid problems in waterways, and the loss or drying out of some natural wetland areas.

BEFORE: A drained wetland on the Clarence floodplain
BEFORE: A drained wetland on the Clarence floodplain
AFTER: Swamp couch one month after works were undertaken to retain water
AFTER: Swamp couch one month after works were undertaken to retain water

Management of the project

The project is coordinated by a steering committee made up of members who represent landholders, the fishing industry, the cane industry, community groups, the Council, Local Land Services and NSW government agencies with a role in resource management on the floodplain.

Day to day running of the project is carried out by a small and dedicated team of staff within the Clarence Valley Council. Staff work closely with landowners to develop management plans for creeks, drains and wetlands. Landowners often become authorised 'floodgate operators' and manage the systems once works are completed.

The success of this project has largely been due to the help and cooperation of landowners, who have made a major contribution towards this project.

wetlands cows Upper Shark Creek

 

Funding

Funding for the project has come mainly from State and Federal Government funding grants, through organisations such as the Northern Rivers Local Land Services, Office of Environment & Heritage, the State Environmental Restoration Trust and from Council funding.

On-ground works

Recent advances in floodgate engineering have allowed flood mitigation structures to be modified to reduce impacts on watercourses in non-flood times, while still providing flood protection.

A wide range of structures have been used to open floodgated watercourses to the river or manage water levels. These include tidal floodgates, winches to lift floodgates, 'fish flaps' in weirs, and a range of water retention structures that can be used to raise water levels.

Since the project began in 1997 more than 200 km of waterways have been opened up and restored. Some 250 landowners have been actively involved in the management of creeks and drains, and more than 60 drain and watercourse management plans have been put in operation.

Head and discharge water retention structure

Landholders opening a winch to improve drain flushing

Tidal floodgate with winch

Head and discharge water
retention structure
Landholders opening a winch
to improve drain flushing
A tidal floodgate with winch allows
for improved water exchange

Benefits of the project

Benefits from active management are usually a combination of the following:

  • increased tidal exchange to improve water quality
  • improved passage, habitat and breeding areas for fish and other aquatic species
  • reduced risk of fish kills
  • better control of introduced aquatic weeds
  • reduced incidence of algal blooms
  • neutralisation of acid water in creeks with salt water from the river
  • raised watertables in acid sulfate areas (limiting further oxidation)
  • improved drainage following floods
  • better water retention and water level control on wetland areas
  • increased grazing productivity on previously drained wetlands during drier months of the year
  • improved waterbird habitat
  • better control of ground water levels
  • stabilised bank erosion
  • stabilised stock access points and exclusion of stock from unstable banks (areas where they are likely to bog)
Restores wetlands at Little Broadwater Restoring habitat values Improving floodplain grazing
Restored wetlands at
Little Broadwater
Restoring habitat values Improving floodplain grazing

Monitoring

Water quality monitoring programs are carried out by Clarence Floodplain Project staff. They have an extensive database for many of the creeks and drains on the Clarence floodplain.

Research

A wide range of research projects related to the project have been carried out, or are currently being carried out, by research organisations such as the NSW Department of Primary Industries, University of New England and Southern Cross University. This includes work on fish passage, water quality, waterbirds, and grazing management on wetlands.

Sampling DO at Palmers Channel Testing soil hydraulic conductivity Monitoring ground water

Sampling dissolved oxygen at
Palmers Channel

Testing soil hydraulic
conductivity

Monitoring ground water

An award winning project

The Clarence Floodplain Project has proven to be very successful. This has been acknowledged through the following awards:

  • 2009/2010 Local Government Excellence in the Environment Awards -Category winner - Natural Environment Protection and Enhancement: On-Ground Works Award - "Lake Wooloweyah Erosion Control Project"
  • 2008 National Awards for Local Government - National Award for Excellence - "The Clarence Floodplain Project - Reviving Floodplain Watercourses and Wetlands"
  • 2008 National Awards for Local Government - Category winner - Natural Resource Management - "The Clarence Floodplain Project - Reviving Floodplain Watercourses and Wetlands"
  • 2007 Banksia Environmental Award - Local Government Category - Finalist
    Project title: The Clarence Floodplain Project - Reviving floodplain watercourses and wetlands

Since their inception in 1989, The Banksia Environmental Awards have earned the reputation as the most prestigious environmental awards in Australia. The awards acknowledge excellence, dedication and leadership in various areas that contribute to the environment and a sustainable future.

  • 2005/06 Local Government and Shires Associations of NSW Excellence in the Environment Awards - Biodiversity Management Award - Joint Winner Division B - Project title: Returning the tides to Poverty Creek
     
  • 2004 National Awards for Local Government - Integrating Biodiversity Conservation into Planning and Management - Highly Commended - Project title: The Clarence Floodplain Project

    2003/04 Local Government and Shires Associations of NSW Excellence in the Environment Awards - Water Quality/Catchment Management Award - Winner Division B and Category Winner - Project title: The Clarence Floodplain Project.

 

Visit Global Restoration NetworkThe "Clarence Floodplain Project" - Global Restoration Network Report has been judged as one of Australasia's Top 25 Ecological restoration projects.

For more information on this project please down load the following document - Clarence Floodplain Project Overview

 

 

 

 

Other Websites