Wetlands - Holder (Lower Molonglo catchment)

Aerial photograph of Holder wetlands

26/03/2019 - Macrophyte planting completed and the plants are in the establishment period.

24/10/2018 - Planting will be finished this week.

2/8/2018 - Construction is now complete as is the dry land planting. Macrophytes (wetland plants) will be planted in the warmer spring months.

8/8/2018 – Site fences will remain in place until late October to allow an extra growing season for dryland grasses.

9/10/2018 - Boundary fencing to be removed this week and replaced by lower fencing around waterbodies.

16/10/2018 - Macrophytes (water plants either in or around the wetland) planting starting soon.


The popular Centenary Trail will soon weave its way through new wetlands at Holder, with construction due to commence in November 2017 and be finished in 2018.

The Centenary Trail passes through the currently vacant land. During construction, part of the shared path will be diverted and cyclists and walkers using the trail may have to cross access roads or wait for site traffic to pass. Everyone is urged to take care while in the area.

The finished wetland will cover 5,600m2 and, when full, contain approximately 2.4 million litres of water (about the  same as an Olympic swimming pool).

Water will be diverted from existing stormwater pipes in the area to the wetlands before flowing into Weston Creek and the Molonglo River.

Catchment Lower Molonglo
Start date November 2017
Construction finished July 2018
Anticipated vegetation establishment periodTwo years from open date*
Open for public useOctober 2018

+ Construction may be delayed by a number of factors, including bad weather.
^ The vegetation establishment period may change depending on ground and weather conditions.
* Some areas of the site may remain closed to allow for plants to establish.

Design changes

During the final design phase, a number of changes were made to the original concept designs to accommodate community feedback, make best use of the existing terrain, reduce project costs and maximise water quality outcomes.

  • Detailed survey of  the terrain and the local stormwater system meant the wetland was resized—including reducing the number of sediment ponds from three to one—to match the inflow  and to avoid unnecessary excavation.
  • Two open drains were  diverted to the main sediment pond. A third drain will be reshaped and revegetated to allow in-line water treatment.
  • The final design includes a new gross pollutant trap and two new trash racks to capture litter and other large pollutants.

More information

Find out what you can do on your own block to improve water quality in our lakes and waterways.

Learn more about how a wetland works.

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How this project might impact you

  • Trucks will pass in and out of the area during the improvement work. Routes have been established to minimise traffic disruption and noise.
  • Detours for walkers and cyclists will be in place and will be clearly signposted.
  • The construction site will be fenced for public safety during the entire length of the project.
  • The contractor has prepared a Construction Environment Management Plan (CEMP) to detail how it  will deal with flora and fauna issues.

Landscape design plan

Wetlands landscape design plan