Projects under this method can earn Australian carbon credit units (ACCUs) by reintroducing tidal flow to a coastal wetland.

For more information, you can refer to our full guide on understanding a blue carbon project. 

When to use this method

The tidal restoration of blue carbon ecosystems method may be suitable if you have a tidal restriction mechanism in place and can:

  • change or remove this mechanism
  • reintroduce tidal flows and flooding by changing or removing this mechanism.

This results in the:

  • rewetting of drained coastal wetland ecosystems
  • conversion of freshwater wetlands to brackish or saline wetlands.


To be eligible, you need to prepare documents for your project:

  • a hydrological assessment to estimate the tidal inundation that could results from project activities
  • a project operations and maintenance plan, with an overview of intended project activities, and any ongoing maintenance needed for project infrastructure to continue to operate as intended
  • a project extent map that identifies key features of the land impacted by tidal inundation from project activities
  • an acid sulphate soils management plan and mosquito management plan, if required by government, state or territory law.

You must also meet general eligibility requirements for the Australian Carbon Credit Unit (ACCU) Scheme.


Excluded activities are:

  • applying fertiliser
  • growing crops and grazing by livestock
  • farming, harvesting or breeding of fish, molluscs, crustaceans, algae, aquatic plants and other organisms.

Method requirements

A project activity is the removal or modification of a tidal restriction mechanism to reintroduce tidal flow. It must establish coastal wetland ecosystems.

Projects may be required to use existing or drainage infrastructure.

Projects can modify, install or construct new infrastructure or drainage infrastructure to manage tidal inundation that occurs as a result.

Your project must maintain tidal flow to the project area throughout the project permanence period. This ensures that the sequestered carbon remains in the vegetation and soils.

You must engage with a qualified engineer for your project operations and maintenance plan.

You must produce:

  • acid sulfate soil management plan
  • mosquito management plan.

You also need a qualified specialist to prepare a hydrological assessment for your project registration application.

The hydrological assessment must include:

  • projected sea level rise
  • your project activities
  • project start tidal inundation map
  • permanence period tidal inundation map
  • your project maintenance plan.

The hydrological assessment must be reviewed by a qualified person and engineer.

You can find more information by referring to our full guide on understanding a blue carbon project

25 years

There are 3 components for coastal wetland ecosystems that contribute to carbon abatement:

  • soil carbon sequestration, through vertical accretion
  • carbon sequestered above and below ground vegetation biomass
  • emissions avoided from introducing tidal flow.

To measure the carbon impact of a project in these areas, we use the Blue Carbon Accounting Model (BlueCAM). It simplifies the process and saves money by not requiring physical samples.

For information on BlueCAM, you can view our BlueCAM video series.

Net abatement is calculated by adding the change in carbon stored in vegetation and soils to the change in avoided emissions:

  • The change in stored carbon is calculated by comparing the land type at the beginning and end of each reporting period.
  • The change in avoided emissions is calculated using the baseline emission levels for each carbon estimation area.

The net abatement calculation also accounts for any emissions resulting from your project, including:

  • any direct impacts on forests and vegetation due to the introduction of tidal flows
  • fuel used for the operation of heavy machinery when carrying out project activities
  • soil disturbance because of excavation activities.

Projects under this scheme have permanence obligations.

Discounts for sequestration abatement

A sequestration buffer applies to the sequestration abatement. This buffer is in place of a permanence period discount and risk of reversal buffer.

There are the following sequestration abatement discounts applicable for projects:

  • 25-year permanence period projects have a 25% discount
  • 100-year permanence period project with minimum 80% of project land identified as impacted land have a 5% discount
  • 100-year permanence period project with maximum 80% of project land identified as impacted land have a 25% discount.

You must monitor:

  • the establishment of coastal wetland ecosystems during the crediting period, including the year and location
  • natural disturbances in your project area during the permanence period.

You need to keep records of:

  • the type and quantity of fuel used when undertaking project activities in each reporting period
  • the area of land, in hectares, disturbed by excavation activities in each reporting period
  • the information you used to prepare or revise your project operations and maintenance plan.

You can choose how often to submit offset reports to us. The minimum time is 6 months, and the maximum is 5 years.

We provide you with an audit schedule when your project's declared.

You must provide audit reports according to this schedule.

We schedule at least 3 audits and additional audits can be triggered.

For more information, you can refer to our audit page.