diff --git a/.github/workflows/create-deployment-spack.yml b/.github/workflows/create-deployment-spack.yml
index 8f8fcbc..9ce8044 100644
--- a/.github/workflows/create-deployment-spack.yml
+++ b/.github/workflows/create-deployment-spack.yml
@@ -16,6 +16,12 @@ on:
         required: true
         default: main
         description: A version of ACCESS-NRI/spack-config
+      deployment-location:
+        type: string
+        required: true
+        description: |
+          A path in the deployment environment where Spack should be created.
+          For example, if it is `opt/spack`, spack will be installed under `opt/spack/<spack-version>/`
 jobs:
   create-spack:
     name: Spack
@@ -39,7 +45,7 @@ jobs:
 
       - name: Install
         env:
-          ROOT_VERSION_LOCATION: ${{ vars.ROOT_SPACK_LOCATION }}/${{ steps.strip.outputs.version-dir }}
+          ROOT_VERSION_LOCATION: ${{ inputs.deployment-location }}/${{ steps.strip.outputs.version-dir }}
         # This step will fail if `mkdir` fails to create a version directory (e.g. `0.20` is already deployed and exists)
         run: |
           ssh ${{ secrets.SSH_USER }}@${{ secrets.SSH_HOST }} -i ${{ steps.ssh.outputs.private-key-path }} /bin/bash <<'EOT'
diff --git a/.github/workflows/deploy-1-setup.yml b/.github/workflows/deploy-1-setup.yml
index 32c10c6..cc6c96b 100644
--- a/.github/workflows/deploy-1-setup.yml
+++ b/.github/workflows/deploy-1-setup.yml
@@ -1,6 +1,16 @@
 name: Deployment Setup
 on:
   workflow_call:
+    inputs:
+      type:
+        type: string
+        required: false
+        default: release
+        description: The type of deployment - either 'release' or 'prerelease'
+      version:
+        type: string
+        required: true
+        description: The version of the model being deployed
 jobs:
   setup-spack-env:
     name: Setup Spack Environment
@@ -15,22 +25,31 @@ jobs:
         run: echo "model=$(echo ${{ github.event.repository.name }} | tr [:upper:] [:lower:])" >> $GITHUB_OUTPUT
       - name: Set Spack Env Name String
         id: get-env-name
-        # replace occurences of '.' with '_' in environment name as spack doesn't support '.'. Ex: 'access-om2-v1.0.0' -> 'access-om2-v1_0_0'.  
-        run: echo "env-name=$(echo '${{ steps.get-model.outputs.model }}-${{ github.ref_name }}' | tr '.' '_')" >> $GITHUB_OUTPUT
-  
+        # replace occurences of '.' with '_' in environment name as spack doesn't support '.'. Ex: 'access-om2-v1.0.0' -> 'access-om2-v1_0_0'.
+        run: echo "env-name=$(echo '${{ steps.get-model.outputs.model }}-${{ inputs.version }}' | tr '.' '_')" >> $GITHUB_OUTPUT
+
   setup-deployment-env:
     name: Setup Deployment Environment
     runs-on: ubuntu-latest
     outputs:
       deployment-environments: ${{ steps.get-deployment-environment.outputs.deployment-environments }}
     steps:
-      - name: Checkout config
+      - name: Checkout Config
         uses: actions/checkout@v4
         with:
           repository: access-nri/build-cd
-      - name: Get environments
+
+      - name: Get Environments
         id: get-deployment-environment
-        run: echo "deployment-environments=$(jq --compact-output '.environments' ./config/deployment-environment.json)" >> $GITHUB_OUTPUT
+        run: |
+          if [[ "${{ inputs.type }}" == "release" ]]; then
+            echo "deployment-environments=$(jq --compact-output '.environments' ./config/deployment-environment.json)" >> $GITHUB_OUTPUT
+          else if [[ "${{ inputs.type }}" == "prerelease" ]]; then
+            echo "deployment-environments=$(jq --compact-output '.prerelease-environments' ./config/deployment-environment.json)" >> $GITHUB_OUTPUT
+          else
+            echo "::error::The 'type' input was invalid. Check the inputs documentation."
+            exit 1
+          fi
 
   deployment:
     name: Deployment
@@ -43,8 +62,9 @@ jobs:
         deployment-environment: ${{ fromJson(needs.setup-deployment-env.outputs.deployment-environments) }}
     uses: access-nri/build-cd/.github/workflows/deploy-2-start.yml@main
     with:
+      type: ${{ inputs.type }}
       model: ${{ needs.setup-spack-env.outputs.model }}
-      version: ${{ github.ref_name }}
+      version: ${{ inputs.version }}
       env-name: ${{ needs.setup-spack-env.outputs.env-name }}
       deployment-environment: ${{ matrix.deployment-environment }}
     secrets: inherit
diff --git a/.github/workflows/deploy-2-start.yml b/.github/workflows/deploy-2-start.yml
index ecd5888..345605c 100644
--- a/.github/workflows/deploy-2-start.yml
+++ b/.github/workflows/deploy-2-start.yml
@@ -3,6 +3,10 @@ concurrency: ${{ inputs.deployment-environment }}
 on:
   workflow_call:
     inputs:
+      type:
+        type: string
+        required: true
+        description: The type of deployment - either 'release' or 'prerelease'
       model:
         type: string
         required: true
@@ -72,11 +76,14 @@ jobs:
 
       # Release
       - name: Get Release Metadata
+        if: inputs.type == 'release'
         run: |
           rsync -e 'ssh -i ${{ steps.ssh.outputs.private-key-path }}' \
             '${{ secrets.USER}}@${{ secrets.HOST_DATA }}:${{ vars.SPACK_LOCATION }}/var/spack/environments/${{ inputs.env-name }}/spack.*' \
             ./${{ inputs.env-name }}
+
       - name: Create Release
+        if: inputs.type == 'release'
         uses: softprops/action-gh-release@v0.1.15
         with:
           tag_name: ${{ inputs.version }}
diff --git a/.github/workflows/undeploy-1-setup.yml b/.github/workflows/undeploy-1-setup.yml
new file mode 100644
index 0000000..5a6136b
--- /dev/null
+++ b/.github/workflows/undeploy-1-setup.yml
@@ -0,0 +1,55 @@
+name: Undeployment Setup
+on:
+  workflow_call:
+    inputs:
+      version-pattern:
+        type: string
+        required: true
+        description: A wildcard-supported string for version(s) of the model being removed
+jobs:
+  get-spack-env:
+    name: Get Spack Environment
+    runs-on: ubuntu-latest
+    outputs:
+      model: ${{ steps.get-model.outputs.model }}
+      env-name: ${{ steps.get-env-name.outputs.env-name }}
+    steps:
+      - name: Get Model
+        id: get-model
+        # for the cases where the repo name is in uppercase but the package name is lowercase (eg. access-nri/MOM5)
+        run: echo "model=$(echo ${{ github.event.repository.name }} | tr [:upper:] [:lower:])" >> $GITHUB_OUTPUT
+      - name: Set Spack Env Name String
+        id: get-env-name
+        # replace occurences of '.' with '_' in environment name as spack doesn't support '.'. Ex: 'access-om2-v1.0.0' -> 'access-om2-v1_0_0'.
+        run: echo "env-name=$(echo '${{ steps.get-model.outputs.model }}-${{ inputs.version-pattern }}' | tr '.' '_')" >> $GITHUB_OUTPUT
+
+  get-prerelease-deployment-env:
+    name: Get Prerelease Deployment Environment
+    runs-on: ubuntu-latest
+    outputs:
+      deployment-environments: ${{ steps.get-deployment-environment.outputs.deployment-environments }}
+    steps:
+      - name: Checkout Config
+        uses: actions/checkout@v4
+        with:
+          repository: access-nri/build-cd
+
+      - name: Get Environments
+        id: get-deployment-environment
+        run: echo "deployment-environments=$(jq --compact-output '.prerelease-environments' ./config/deployment-environment.json)" >> $GITHUB_OUTPUT
+
+
+  undeployment:
+    name: Remove Deployment
+    needs:
+      - get-spack-env
+      - get-prerelease-deployment-env
+    strategy:
+      fail-fast: false
+      matrix:
+        deployment-environment: ${{ fromJson(needs.get-prerelease-deployment-env.outputs.deployment-environments) }}
+    uses: access-nri/build-cd/.github/workflows/undeploy-2-start.yml@main
+    with:
+      deployment-environment: ${{ matrix.deployment-environment }}
+      env-name: ${{ needs.get-spack-env.outputs.env-name }}
+    secrets: inherit
diff --git a/.github/workflows/undeploy-2-start.yml b/.github/workflows/undeploy-2-start.yml
new file mode 100644
index 0000000..110c623
--- /dev/null
+++ b/.github/workflows/undeploy-2-start.yml
@@ -0,0 +1,52 @@
+name: Undeployment Start
+on:
+  workflow_call:
+    inputs:
+      env-name:
+        type: string
+        required: true
+        description: The spack-env-compliant model name to remove
+      deployment-environment:
+        type: string
+        required: true
+        description: The GitHub deployment environment name
+jobs:
+  undeploy-from-environment:
+    name: Undeploy ${{ inputs.env-name }} from ${{ inputs.deployment-environment }}
+    runs-on: ubuntu-latest
+    environment: ${{ inputs.deployment-environment }}
+    steps:
+      - name: Setup SSH
+        id: ssh
+        uses: access-nri/actions/.github/actions/setup-ssh@main
+        with:
+          private-key: ${{ secrets.SSH_KEY }}
+          hosts: |
+            ${{ secrets.HOST }}
+            ${{ secrets.HOST_DATA }}
+
+      - name: Undeploy
+        # ssh into deployment environment, create and activate the env, remove all the unneeded environments
+        id: undeploy
+        run: |
+          ssh ${{ secrets.USER}}@${{ secrets.HOST }} -i ${{ steps.ssh.outputs.private-key-path }} /bin/bash <<'EOT'
+          . ${{ vars.SPACK_CONFIG_LOCATION }}/spack-enable.bash
+          envs=$(find ${{ vars.SPACK_LOCATION }}/var/spack/environments -type d -name '${{ inputs.env-name }}' -printf '%f ')
+
+          for env in $envs; do
+            spack env activate $env
+            spack uninstall --remove --dependents --yes-to-all --all
+            spack env deactivate $env
+            spack env rm $env --yes-to-all
+          done
+          spack gc --yes-to-all
+          EOT
+
+      - name: Undeploy Status Notifier
+        if: always()
+        run: |
+          if [[ "${{ steps.undeploy.outcome }}" == "success" ]]; then
+            echo "::notice::Deployment ${{ inputs.env-name }} was successfully removed from ${{ inputs.deployment-environment }}, found at ${{ vars.SPACK_LOCATION }}"
+          else
+            echo "::error::Deployment ${{ inputs.env-name }} couldn't be removed from ${{ inputs.deployment-environment}}, found at ${{ vars.SPACK_LOCATION }}. Please check manually."
+          fi
diff --git a/README.md b/README.md
index 91594cb..03d826e 100644
--- a/README.md
+++ b/README.md
@@ -1,41 +1,102 @@
 # build-cd
 
-This repository houses reusable workflows for the building and deployment of ACCESS-NRI models to different environments. 
+This repository houses reusable workflows for the building and deployment of ACCESS-NRI models to different environments.
 
 ## Overview
 
-This repository is broken down into two folders: `config` and `.github/workflows`. 
+This repository is broken down into two folders: `config` and `.github/workflows`.
 
-`config` contains information on the deployment environments that the models deploy to, which is currently just the name of the deployment target. This is used by the aforementioned deployment workflows to gather secrets and configuration details from the associated GitHub Environment. 
+`config` contains information on the deployment environments that the models deploy to, which is currently just the name of the deployment target. This is used by the aforementioned deployment workflows to gather secrets and configuration details from the associated GitHub Environment.
 
 `.github/workflows` houses validation and reusable deployment workflows that are called by ACCESS-NRI model repositories. Currently, only [ACCESS-NRI/ACCESS-OM2](https://github.com/ACCESS-NRI/access-om2) is supported.
 
-Below is a brief summary of the two pipelines, `deploy-*` and `validate-json`.
+Below is a brief summary of the three pipelines, `deploy-*`, `undeploy-*` and `validate-json`.
 
-### deploy-*
+### `deploy-*`
 
-This pipeline is responsible for the gathering of configuration information, building and deployment of whatever model repository calls it. It is split into two workflows, as noted below. 
+#### Inputs
 
-#### deploy-1-setup.yml
+| Name | Type | Description | Required | Default | Example |
+| ---- | ---- | ----------- | -------- | ------- | ------- |
+| `type` | string | The type of deployment - either 'release' or 'prerelease' | true | `release` | `prerelease` |
+| `version` | string | The version of the model being deployed | true | N/A | `2024.01.1` |
 
-This workflow obtains the relevant spack and GitHub Environment information, and creates parallelized  deployments based on the list of environments. 
+#### Explanation
 
-#### deploy-2-start.yml
+This pipeline is responsible for the gathering of configuration information, building and deployment of whatever model repository calls it. It is split into two workflows.
 
-Using the GitHub Environment, it `ssh`s into the deployment environments `spack` instance, and installs the model associated with the repository that called it. It then copies back relevant metadata and creates a versioned GitHub Release in the caller repository. 
+##### `deploy-1-setup.yml`
 
-### validate-json
+This workflow obtains the relevant spack and GitHub Environment information, and creates parallelized deployments based on the list of environments.
 
-This workflow is used to validate the `config` folders `*.json` files based on their associated `*.schema.json`. This is used for PR checks on the `build-cd` repo itself. 
+##### `deploy-2-start.yml`
 
-## Usage
+Using the GitHub Environment, it `ssh`s into the deployment environments `spack` instance, and installs the model associated with the repository that called it. It then copies back relevant metadata and creates a versioned GitHub Release in the caller repository, if it is not a `prerelease` deployment.
 
-For supported `spack`-installable ACCESS-NRI models, simply call the `deploy-1-setup.yml` reusable workflow from the given repositories workflow file, like so:
+#### Usage
+
+For supported `spack`-installable ACCESS-NRI models, simply call the `deploy-1-setup.yml` reusable workflow from the given repositories workflow file, as shown below. Don't forget to add required inputs!
 
 ```yml
 deploy:
   uses: access-nri/build-cd/.github/workflows/deploy-1-setup.yml@main
+  with:
+    version: 1.2.3
   secrets: inherit
   permissions:
     contents: write
 ```
+
+### `undeploy-*`
+
+For given `spack` environments, we can also remove deployments.
+
+> [!NOTE]
+> This workflow is not one that should be used directly. It is used within the automated deployment pipeline to remove prerelease builds of models.
+
+#### Inputs
+
+| Name | Type | Description | Required | Default | Example |
+| ---- | ---- | ----------- | -------- | ------- | ------- |
+| `version-pattern` | string | A wildcard-supported string for version(s) of the model being removed | true | N/A | `2024.01.1-pre*` |
+
+#### Explanation
+
+This pipeline is responsible for removing deployed models from a deployment environment. Particular use-cases include removing `prerelease` builds from a deployment environment once a PR is merged.
+
+##### `undeploy-1-setup.yml`
+
+This workflow obtains the relevant spack and GitHub Environment information, and creates parallelized jobs removing the given `spack` environments based on the list of deployment environments.
+
+##### `undeploy-2-start.yml`
+
+Using the GitHub Environment, it `ssh`s into the deployment environments `spack` instance, and installs the model associated with the repository that called it. It then copies back relevant metadata and creates a versioned GitHub Release in the caller repository, if it is not a `prerelease` deployment.
+
+#### Usage
+
+```yml
+remove-prereleases:
+  uses: access-nri/build-cd/.github/workflows/undeploy-2-setup.yml@main
+  with:
+    version-pattern: ${{ inputs.model }}-pre*
+  secrets: inherit
+```
+
+This will remove every `spack` environment from the deployment target that matches `<model>-pre*`.
+
+### `validate-json.yml`
+
+This workflow is used to validate the `config` folders `*.json` files based on their associated `*.schema.json`. This is used for PR checks on the `build-cd` repo itself.
+
+### `create-deployment-spack.yml`
+
+This workflow_dispatch-triggered workflow is used to create a version of `spack` on `Gadi`.
+
+#### Inputs
+
+| Name | Type | Description | Required | Default | Example |
+| ---- | ---- | ----------- | -------- | ------- | ------- |
+| `spack-version` | string | A version of `spack` | true | N/A | `0.20` |
+| `spack-packages-version` | string | A version of ACCESS-NRI/spack-packages to be bundled with the install of `spack` | true | `main` | `2023.11.12` |
+| `spack-config-version` | string | A version of ACCESS-NRI/spack-config to be bundled with the install of `spack` | true | `main` | `2024.01.01` |
+| `deployment-location` | true | A path in the deployment environment where Spack should be created. For example, if it is `opt/spack`, spack will be installed under `opt/spack/<spack-version>/` | true | N/A | `/opt/spack` |
diff --git a/config/deployment-environment.json b/config/deployment-environment.json
index 5e57e95..bb3ec0e 100644
--- a/config/deployment-environment.json
+++ b/config/deployment-environment.json
@@ -2,5 +2,8 @@
     "$schema": "./deployment-environment.schema.json",
     "environments": [
         "Gadi"
+    ],
+    "prerelease-environments": [
+        "Gadi Prerelease"
     ]
 }
\ No newline at end of file
diff --git a/config/deployment-environment.schema.json b/config/deployment-environment.schema.json
index 0519787..187c770 100644
--- a/config/deployment-environment.schema.json
+++ b/config/deployment-environment.schema.json
@@ -12,8 +12,14 @@
             "items": {
                 "type": "string"
             }
+        },
+        "prerelease-environments": {
+            "type": "array",
+            "items": {
+                "type": "string"
+            }
         }
     },
-    "required": ["environments"],
+    "required": ["environments", "prerelease-environments"],
     "additionalProperties": false
 }
\ No newline at end of file