Raising Clarrie Hall Dam

17 July 2018

Council will call for Request(s) for Offer to agist three properties Council has purchased for the raising of Clarrie Hall Dam, namely:

• 511 Doon Doon Road, approximately 50ha

• 426 Commissioners Creek Road, approximately 101ha, and

• 701 Doon Doon Road (currently under contract to be sold to Council), approximately 74ha.

The properties are being offered for cattle agistment either separately or as a whole for a period of two years, with any option to extend being solely at the discretion of Council. It is intended that the agistment will end prior to the start of construction to raise the wall of the dam.

The terms of agistment will be set out in the Request for Offer documents.

Prior to signing any agreement with the successful bidder, Council will complete a Conditions Report of the property/s and this will form the basis of the agreed condition the property is to be kept in.

The Request for Offer will be advertised in the Tweed Link shortly.

Thursday 12 July 2018

Council has achieved a significant milestone towards augmenting the shire’s water supply by applying to the NSW Government for the environmental planning assessment requirements for raising the wall of Clarrie Hall Dam.

The Department of Planning and Environment accepted Council’s application for approval to proceed with the project as State Significant Infrastructure and will be issuing the criteria against which the project will be assessed.

Council lodged a Preliminary Environmental Assessment report with the Department, which summarises the justification, scope of works and potential environmental and social impacts of the project. This information is required by the State Government to develop the Secretary’s Environmental Assessment Requirements or SEARs (also referred to as the Environmental Impact Statement requirements). The assessment report can be found in the Document Library at https://www.yoursaytweed.com.au/ClarrieHallDam.

In its application Council advised the State Government there was a requirement to augment the water supply by 2026.

“Option studies have consistently shown that raising Clarrie Hall Dam is the preferred option to increase the shire’s water supply,” Council Project Manager Robert Siebert said of the application.

Council proposes to raise the dam wall by 8.5 metres, substantially increasing the dam’s capacity to 42,300 megalitres and securing an adequate water supply for the shire to approximately 2046.

The project may also need approval from the Commonwealth Government for impacts to Commonwealth protected flora and fauna.

The Flora and Fauna Assessment undertaken by Council as part of project planning has identified that several Commonwealth threatened species would be affected by the raising of the dam, including the Giant Barred Frog (Mixophyes iteratus),the Red Lilly Pilly (Syzygium hodgkinsoniae) and a patch of lowland rainforest.

Council will now work with the NSW and Commonwealth governments to develop strategies to avoid and minimise impacts on these and other environmental values in the area.

Council also is establishing vegetation restoration trial sites for the revegetation of the land it purchases for the raising of the dam and is working with the NSW Biodiversity Conservation Trust to ensure these restoration sites are managed in accordance with new biodiversity legislation.

The initial Archaeological Assessment and Aboriginal Cultural Assessment for the project has been completed and that report can be found in the Document Library at https://www.yoursaytweed.com.au/ClarrieHallDam.

Environmental Flow studies are continuing.

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4 July 2018

While a project to raise Clarrie Hall Dam is still in its early planning and land acquisition stage, it offers Council the opportunity to trial a range of vegetation restoration actions to regenerate lands purchased for the bigger dam.

From the lands purchased, Council has identified a large parcel it will establish as a restoration trial site for benchmarking the success of revegetation efforts and the return of native fauna to land previously cleared for cattle grazing. Revegetating land adjacent to the dam will complement the existing catchment buffer zone.

In establishing the restoration trial site, Council will measure fauna activity on the property prior to any revegetation works being undertaken and then monitor changes in fauna activity over time.

The trail restoration property has about 54 hectares of advanced regrowth forest, including a number of threatened flora and fauna species. Council will prioritise weed management within threatened species habitat to assist in the conservation of these species. In other areas, various restoration techniques would be implemented to promote natural regeneration. In some instances, where a high level of intervention is warranted, tubestock would be planted.

Council’s aim in restoring the trial site is to recreate the mixed eucalypt open forest that would have existed prior to the property being cleared.

The regeneration of the characteristic Brush Box, Pink Bloodwood, Tallowwood, Grey Ironbark, White Mahogany and Grey Gum will signal the reestablishment of native vegetation communities and will assist in stabilising soil in the water supply catchment and improve habitat values for native fauna, such as glossy black cockatoos, koala, forest owls and insectivorous bats.

Restoration of the site also will improve connectivity of vegetation corridors in the Doon Doon catchment to assist wildlife movement and genetic transfer.

Over coming years, the data collected from the restoration site may be valuable in evidencing the success of the various regeneration methodologies which, in turn, will enable successful and cost-effective approaches to restoring other properties in the catchment and further afield.

The Restoration Strategy for the trial site is available in the Document Library on this site.

Thursday 28 June, 2018

Council consultants have completed the first survey of Doon Doon Creek and the Tweed River down to Bray Park Weir to determine how a raised Clarrie Hall Dam may affect fish and other aquatic species.

The scientists from Eco Logical last week studied 18 kilometres of waterway, noting habitat features of the river and the location of pools, riffles (rocky or shallow parts with rough water) and rapids.

They took 640 depth-readings and found depths ranging from just a few centimetres to one pool 10 metres deep in the river.

During the survey they sighted Australian bass, freshwater catfish and schools of freshwater mullet.

The scientists will return to the Tweed in spring and summer to look for fish, frogs and other aquatic creatures at six sites identified in last week's survey. To do this, they will rely on both visual sightings and nets.

They also will install loggers to monitor the dissolved oxygen content and temperature in the water, and any changes to them over the seasons. This will inform Council of any layers within the deep pools, which are low in oxygen or colder …. (and the why behind it).

The scientists will return to monitor the waterways during a release from Clarrie Hall Dam, if and when one is required. Releases occur during times of low flow to ensure the continued health of the waterway or, occasionally, to assist to hold back a saltwater high tide from overtopping the Bray Park Weir pool.

From the field data collected, Eco Logical will recommend an environmental flow regime from the dam that will minimise any impact of the raising of dam wall on the downstream ecology while maintaining water security for the Tweed Shire.

8 June 2018

Council consultants will begin to map aquatic habitat in Doon Doon Creek and the Tweed River next week to determine how the raising of Clarrie Hall Dam may impact on fish and other aquatic species.

Scientists from EcoLogical will undertake the field research, both walking and in canoes, to map critical habitat features such as pools and riffles (rocky or shallow part with rough water) and determine the number of species within the impacted waterways and the population of each species.

The field work will be undertaken for several days every season over the next year, starting on Monday 18 June.

Property owners adjoining Doon Doon Creek and the Tweed River downstream of Clarrie Hall Dam are advised they may see a small team of scientists working on and at the water’s edge. The scientists’ schedule is:

Monday 18 June – walk Doon Doon Creek to the start of the Tweed River

Tuesday 19 June – canoe from start of Tweed River to Lange Road bridge

Wednesday 20 June – canoe from Lange Road Bridge to crossing (north of 886 Kyogle Road)

Thursday 21 June – canoe from crossing to Bray Park Weir.

The field work will continue into the night, as the scientists identify and count frog species.

From the field data collected, EcoLogical will attempt to identify measures to mitigate any impact the dam has and, if raised, will have on the aquatic environment. It is hoped measures to improve the present aquatic environment can be found and implemented.

The methodology to be used by the EcoLogical scientists for the Clarrie Hall Dam Environmental Flows Assessment can be found in the Document Library.

The EcoLogical team also would like to learn from local knowledge about the flora and fauna in the creek, or observations of the creek. Residents with information can provide that direct via the Guestbook button on this site or by contacting them via Council by telephoning (02) 677 2400.

Thursday 26 April 2018

Council last week adopted a recommendation to build a new bridge parallel to the existing McCabe’s Bridge at Doon Doon to provide road access to residents of Commissioners Creek after the wall of Clarrie Hall Dam is raised.

The decision followed a number of studies and 12 months’ consultation with the affected residents. The residents nominated a new bridge as their preferred option at a stakeholder meeting at Doon Doon Hall on Tuesday 20 March.

The residents’ preference was presented to Council as the preferred option and adopted unanimously.

Council will now begin work on the detailed design and environmental assessment for constructing the new bridge. This work will take about a year.

The new bridge will be six metres higher than the existing bridge and require the raising and upgrading of 700 metres of road approach on both sides. It will be a three-span, 50-metre-long concrete bridge with two four-metre-wide traffic lanes and will cost about $6 million. Construction of the new bridge may begin as early as 2019. The existing bridge will remain in use during bridge construction.

Construction to raise the wall of the dam is due to start in 2023.

At the request of the community, Council undertook a detailed investigation of four options to provide continuing road access into the area after McCabe’s Bridge is inundated. The option preferred by the community was the cheapest, would result in the least environmental disturbance, harm to native flora and fauna and impact on areas of Aboriginal cultural significance and disruption to residents during construction.

The other options presented were for a new bridge on the existing alignment and two road options linking Doon Doon Road and Commissioners Creek Road. More information on all options can be found on the Raising Clarrie Hall Dam project page on Your Say Tweed.

Last week’s decision marks a milestone in the project, which kicked off on 10 December 2015 when Council resolved that ‘based on the information currently available, Council adopts the raising of the wall of the Clarrie Hall Dam as the preferred option for future water security and proceeds with the planning, approval and land acquisitions phase for the project’.

The Concept Design for raising the wall of the dam is being undertaken by New South Wales Public Works, which built the dam in 1982. Land acquisitions are continuing, with 60 per cent of the required purchases completed or under contract. Work has also begun to engage an independent consultant to prepare the Environmental Impact Statement. The process to prepare the Environmental Impact Statement will take about two years before it goes on public exhibition in mid-2020 for community comment.

By early 2021, the project will be set to face its final hurdle before construction begins after a second independent consultant assesses all documentation and public submissions and makes a recommendation to the Minister to proceed or terminate the project.