This reinforced riverbank, just upstream from the Daintree River ferry crossing, was well underwater in the recent flooding rain – so we’re happy to report it has emerged unscathed to continue to do its job of stopping erosion.

One hundred metres of this riverbank was restored last year. Erosion problems had been worsening for years and Cyclone Jasper accelerated things in 2023, sweeping chunks of riverbank down the river and threatening the road running alongside the river.

Our solution, working with partners Neilly Group Engineering, was a combination of engineered rock work, earthworks and revegetation (mangroves, grasses and trees). And tree rootballs were embedded into the rock wall to better protect the mangrove plantings from flooding and to begin to replicate habitat conditions in established mangroves where large logs and branches collect and provide fish habitat.

The reinforced riverbank has now gone through multiple high rainfall events, with the latest nearing record high flows. Mangroves growing on the rockwall’s benching were the only part of the design that was significantly affected in the March flood. They will recover as tidal flows bring more mangrove seedlings from nearby vegetation.

Terrain NRM partnered with the Douglas Shire Council and Jabalbina Rangers for this project, which aims to stop an estimated 1,200 tonnes of fine sediment a year from washing down the river and out to the Great Barrier Reef lagoon

Terrain NRM’s Zack Severino says revegetation is the long-term solution, after a combination of rock and earthworks.

“We were dealing with a sheer drop. With every storm, more soil was getting washed away. Now we have a reinforced riverbank. And the upland area has been planted out with native, fast-growing trees to get a good root system embedded. Mangroves have been planted on the benched areas to catch sediment and more seedlings, so that’ll also help to secure the riverbank, and also filter the water.

The ‘Daintree Wetlands: Reef Coastal Restoration in the Lower Daintree’ project is being delivered by Terrain NRM through funding from the Australian Government’s Reef Trust through their Reef Coastal Restoration Program grant.

It’s a busy time of year for our Water Quality Monitoring Team! With the intense rain event between Christmas and New Year’s Eve, the crew was out most days. (It’s lucky they love the wet.)

We have automatic sensor results from 11 locations across the Innisfail-Tully region and our team, along with 3C Farms, collected water samples from Utchee, Kennedy and Corduroy creek sites, and the Sandy Creek wetland.

Over that period, we amassed 170+ samples.

The water has been sent to laboratories for nutrient, sediment and pesticide analysis. The results will be shared with local landholders.

We’ve been collecting samples from some areas for 8 years now. They’re helping all of us to better understand how our activities in catchments affect water quality, and how wetlands can improve water quality by removing nitrogen and sediment.

Our water quality monitoring projects are funded by the Queensland Government’s Office of the Great Barrier Reef and World Heritage and the partnership between the Australian Government’s Reef Trust and the Great Barrier Reef Foundation.

Feral pig and woody weed control programs are beginning in the Herbert catchment as Terrain NRM and its partners intensify efforts to improve water quality in a river system extending from west of Mt Garnet to the floodplain around Ingham.

Five projects are now being rolled out as the first stage of the Herbert Integrated Project’s on-ground works, and Terrain NRM Project Manager Fiona Barron said there were more to follow.

Council leads feral pig control program

One of the first is a feral pig management initiative led by Hinchinbrook Shire Council.

“Feral pigs are a major problem for the environment and also for the sugar cane industry and other farming industries in the Herbert,” Ms Barron said. “Pigs churn up soil and vegetation and damage wetlands and riverbanks, which releases nutrients and can spread pathogens.”

Hinchinbrook Shire Council will build on an existing control program by using emerging surveillance and control technologies, including AI-enabled cameras. A remote-triggering feral-tech trap door will also be trialled near a coastal community where traditional systems have been unsuccessful.

Woody weeds removal in Upper Herbert region

In the upper Herbert, stakeholders identified the thickening of invasive woody weeds, such as lantana, as a priority.

“Dense thickets of woody weeds are a problem for graziers because they lead to less soil protection and pasture,” Ms Barron said.

“Part of the project will involve working with graziers on trials of different burn approaches at different times of the year to determine the most effective way of tackling woody weeds so that we can share best practice with other landholders.”

Whole-of-farm and whole-of-catchment planning

Other projects include developing a whole-of-catchment management plan, supporting cane farmers through integrated whole-of-farm planning led by Herbert Cane Productivity Services Ltd, and synthesising past and present water quality monitoring data to better understand what’s happening across the catchment and help farmers and the wider community.

Circular economy, natural capital opportunities

There will also be a focus on circular economy opportunities and natural capital capacity-building within the Herbert catchment area.

Ms Barron said the Herbert Integrated Project was being driven by the community, and Terrain NRM was working with a wide range of partners and community groups.

“We have engaged widely with stakeholders across the upper and lower Herbert catchment to understand how the catchment can be managed as one integrated system – to not only improve water quality but also deliver broader community and landscape benefits,” she said.

A new high-frequency water-quality monitoring station has recently been installed at Corduroy Creek south of Tully. It’s the eleventh for the Tully-Innisfail region and it’s in one of 50+ locations where water monitoring has been happening in paddocks, drains, creeks and rivers across the Tully, Murray and Johnstone River catchments.

Why do we do it and how does it help farmers?

We’re helping farmers to sustainably manage their land. The data is giving all of us a better understanding of how human activities, including land management practices, impact waterways and the Great Barrier Reef. We design water monitoring programs to answer landholders’ questions about water quality. The data is shared with participating landholders and industry bodies. It has led to changes in the way farmers use pesticides and fertiliser, and manage ground cover. Having more knowledge and understanding = good decision making.

Why Corduroy Creek?

Cane growers in this area asked for data. So this creek has been monitored for more than six years now, initially through a project run by Sugar Research Australia and then through two Terrain NRM projects. We chose the same monitoring sites so we can look at trends over time. With long-term datasets, we can track changes in water quality following changes to land management practices. This helps us all to see the effects of different practices and the way changes can make a positive difference to water quality.

How do high-frequency water monitoring stations work?

These stations fill in the gaps between monthly water sampling results. Every half hour, a nitrate sensor takes a measurement. By measuring stream flow as well, we can see changes in nitrate concentrations and we can also calculate the nitrate load moving down the creek (in kilograms) during a single rain event, during the first big flush of the wet season or for an entire year. The new station at Corduroy Creek also has a rain gauge, to help us relate the stream flows and nitrate concentrations to rainfalls, given how localised rain can be.

The bank of the Daintree River has been restored near the ferry crossing – where flooding rain after Cyclone Jasper washed away land and part of a road.

Terrain NRM partnered with the Douglas Shire Council, Jabalbina Rangers and Neilly Group to rebuild 100 metres of riverbank upstream from the ferry crossing recently, and to begin revegetation work including mangrove restoration.

The work is designed to stop an estimated 1,200 tonnes of fine sediment a year from washing down the river and out to the Great Barrier Reef lagoon.

Landholder Colin McDowall says it has been welcomed.

“It was the highest flood we’ve ever seen here, and it did some damage. There had already been erosion in this area over the years with the way the current runs to the side and hits the bank in floods.

Restoration a combination of rocks and mangroves 

“We’re hoping the rocks and mangroves will help to hold the bank together better and save it from this happening again.”

Terrain NRM’s Zack Severino said revegetation is the long-term solution, after a combination of rock and earthworks.

“We were dealing with a sheer drop. With every storm, more soil was getting washed away. Now we have a reinforced riverbank. And the upland area has been planted out with native, fast-growing trees to get a good root system embedded. Mangroves have been planted on the benched areas to catch sediment and more seedlings, so that’ll also help to secure the riverbank, and also filter the water.

Tree rootballs for fish habitat

“Tree rootballs are part of the design, to create fish habitat. Natural processes will build up over time.”

Jabalbina Ranger Manager Rick Burchill said over 100 native trees from Jabalbina and Douglas Shire Council nurseries had been planted at the site.

From local rivers to Sydney’s Macquarie University – three Mamu Rangers and Terrain NRM’s Alicia Buckle recently took a deep dive into the science behind environmental DNA.

Environmental DNA (eDNA): What is it?

Environmental DNA, or eDNA, is changing the way we monitor ecosystems and it’s particularly useful in places where traditional monitoring would be dangerous (because of crocodiles) or would cause too much disturbance (in sensitive ecosystems or for rare and endangered species).

It’s being used for many things – from detecting pest fish like tilapia in our creeks and rivers or seeing whether polluted waterways are becoming healthier to monitoring endangered swordfish or finding crown-of-thorns starfish before they mature and cause major problems on the Reef.

Local waterways: How eDNA sampling helps

For Mamu Rangers, eDNA analysis is helping to monitor culturally significant species without land managers having to spend countless hours searching for them, or installing cameras and traps.

“We are using eDNA sampling to help us determine whether species like gudgeon, barramundi and mangrove jack are present or absent in waterways,’’ Mamu Ranger Francis Joyce says. “From there we’ll look at how to manage our waterways better for them.

“Being at the laboratory was amazing – it gave us more of an appreciation of all the science that happens after our sampling, and why our project’s design and sampling methods are so important.”

Fast Facts: eDNA in the laboratory

DNA is in the biological matter in samples.

Molecules called primers are released into the mixture and they attach to target sections of the DNA strands.

These sections can be used as a ‘barcode’ (like we have on products at a supermarket).

Many copies of the barcode sections are made.

These samples are sequenced to look at what species are present. Just like at the supermarket checkout, DNA barcodes can be matched to species in a database to give us a list of animals and plants found in the sample.

More than 140 people have been part of community workshops focused on the next 10 years of investment in water quality improvements for the Wet Tropics region’s nine river catchments.

From Cardwell to the Tablelands and Cairns, workshops have brought together landholders, industries, traditional owners, river catchment groups and local government. Workshops are also happening further north, in Mossman and the Daintree region, in coming months.

New strategy to guide investment in water quality programs

Terrain NRM’s Charles Hammond said the sessions would help to guide strategic investment in land-based water quality programs over the next decade. Terrain is being funded through the Australian Government’s Reef Trust program to lead the development of catchment priorities.

Identifying regional priorities

“In the workshops, we’ve been identifying regional priorities,’’ Charles said. “We’ve also been looking for opportunities that’ll maximise investment by delivering multiple benefits to the environment and local communities.

“The response has been great. People are telling us how useful it is to talk with other industries and groups, and to share information about a wide range of past, current and future projects and resources.

“They’re seeing just how many organisations are working towards improvements for river catchments and water quality, and the value of working together.”

He said a huge amount of effort and investment had already gone into improving reef water quality over the last 15 years, and good progress had been made.

“There has been significant work with landholders on farm management practice changes to improve everything from the land and production to the quality of water leaving properties.

The rootballs of trees are part of a new engineered solution for erosion along the Herbert River near Ingham.

About 180 metres of flood-damaged riverbank has been repaired using five rootballs combined with more than 2000 tonnes of rock – for a rockwall with a difference.

Strengthening riverbanks, creating fish habitat

Terrain NRM’s Lana Hepburn said the result would both strengthen the riverbank and create fish habitat.

“The hardwood is wedged trunk-first into the lower riverbank so the rootballs are in the water, with rock benching holding them in place,’’ Lana says.

“The rootballs add complexity to the waterway, creating eddies and different flow rates which moves the fast-flowing water away from the toe of the streambank to prevent more erosion. They also create places for fish to rest and feed.

Erosion since 2009 wet season

She said the riverbank had been eroding at the site since 2009 and the 2021-22 wet season had worsened things, with more riverbank vegetation lost to flooding.

“Since 2009, the riverbank has retreated 20 to 40 metres on average across the site. The toe of the riverbank – the point where the riverbed meets the bank and supports the weight of the bank –became completely unvegetated. So when the 12 metre high bank was hit by fast water, it was eroding at the toe and collapsing, sending soil down the river and fine sediment out to the ocean.”

Cane farmer Mark Zatta, whose land borders the river, says he’s “stoked”.

“Originally we had about 50m of rainforest along the river but we were losing it over time. All of a sudden, in one river rise, a whole lot was gone. Once the first wall (of riverbank) dropped, it just kept collapsing. It’s on the outside of a bend in the river where the river pushes around.

A new $3.2 million project will focus on the Herbert catchment – the largest river system in the Wet Tropics which begins on the Atherton Tablelands and flows to the ocean almost 300km away at Ingham.

Workshops with a wide range of representatives

Terrain NRM is working with a wide range of industries and groups to plan for the Herbert Integrated Project, which is funded through the Queensland Government’s Queensland Reef Water Quality Program. More than 40 people have been part of workshops in Ravenshoe and Ingham recently to help determine the best actions to further improve water quality, the land, its resilience, agricultural outcomes and co-benefits for the local community.

Whole-of-catchment approach

Project manager Fiona Barron said a whole-of-catchment outlook was important.

“We will be building on previous projects in this catchment. They include working with farmers on grazing and sugar cane management practice changes to improve everything from the land and production to the quality of water leaving properties. They also include fine-scale water quality monitoring, constructing fishways and repairing streambanks by engineering structures like rock chutes and pile fields.

Building on solid results from previous projects

“Programs delivered over the last 15 years have made good progress. But to meet the 2050 water quality targets, we need to build on past work. This new Herbert project will draw heavily on local knowledge, combined with all the data and science that’s come before, for a program that’s tailor-made to the upper and lower Herbert.

Less soil is being lost to creeks and rivers on the southern Tablelands thanks to changed grazing practices and to solutions like rock chutes for eroded gullies.

Seven farming families have been working with not-for-profit environmental organisation Terrain NRM and grazing and soil health specialists for the last seven years on changes that range from dividing paddocks up and rotating cattle differently to building up vegetation coverage where rock chutes and bund walls have been built to stop gullies from eroding any further.

Graziers say the results include better pastures

“What we’re seeing is more feed and better-quality feed,” Woodleigh Station’s Pete Waddell says. “We’ve fenced to cut paddocks up and we’re now running bigger numbers of cattle on smaller areas rather than the reverse, which is the traditional approach. I’ve seen a marked improvement in the condition of country.’’

Preventing 4,500 tonnes of fine sediment from reaching the Reef annually

Terrain NRM’s Duncan Buckle says the combined impact of 10 erosion-control structures, and grazing management changes across six cattle stations, is keeping thousands of tonnes of soil on the land each wet season and stopping an estimated 4,500 tonnes of the really fine soil particles (the equivalent of 225 semi-trailer loads) from becoming sediment on the Great Barrier Reef each year.

“Fine-tuning grazing management practices and making the land more resilient has been a big part of these two projects,’’ he says.

“It’s the key to reducing erosion in the Herbert River catchment. We’ve been working with graziers to improve the health of grassland ecosystems and cattle, and to improve production.

Managing cattle to improve soil health

“We look at ways to manage cattle to promote soil health because improved soil health results in thicker, healthier, more nutritious pastures. And getting more roots in the soil means the soil can absorb water better and hold together better.”

Grazier Curtis Archer says changes on Glen Ruth Station are creating better pastures and making it easier to handle cattle and control weeds like lantana with fire.

Splitting paddocks for a three-paddock rotation system

“We’ve split paddocks in half and gone to a three-paddock rotation system in the river country and another three-paddock system to manage the creek flats,’’ he says.

“It’s making the cattle work the country better, rather than just sitting on creek flats and always hammering them. It’s giving paddocks a more even graze and we’ve seen the dominant species take over – good native grasses. We’ve got three times the volume of grass in these paddocks, which means we can add a few more cattle now. I think there will be more and more benefits over the years.