diff --git a/Docs/Development_deployment.md b/Docs/Development_deployment.md
index ed18b9625..3590b92d8 100644
--- a/Docs/Development_deployment.md
+++ b/Docs/Development_deployment.md
@@ -27,7 +27,10 @@ Devcontainer (see more details later).
 To develop and build MapComplete, you
 
 0. Make a fork and clone the repository. (We recommend a shallow clone with `git clone --filter=blob:none <repo>`)
-0. Install the nodejs version specified in [.tool-versions](./.tool-versions)
+0. Install `python3` if you do not have it already
+    - On linux: `sudo apt install python3`
+    - On windows: find the latest download on the [Python Releases for Windows page](https://www.python.org/downloads/windows/)
+0. Install the nodejs version specified in [/.tool-versions](/.tool-versions)
     - On linux: install npm first `sudo apt install npm`, then install `n` using npm: ` npm install -g n`, which can
       then install node with `n install <node-version>`
     - You can [use asdf to manage your runtime versions](https://asdf-vm.com/).
@@ -72,11 +75,12 @@ To use the WSL in Visual Studio Code:
    or `userlayout=true#<layout configuration>` as [Query parameter](URL_Parameters.md). Note that the shorter URLs (
    e.g. `bookcases.html`, `aed.html`, ...) _don't_ exist on the development version.
 
-### Dependencie
+Dependencies
+------------
 
 `make` , `python3` `g++`
 
-(run `nix-env -iA nixos.gnumake nixos.gdc nixos.python3`)
+(Nix users may run `nix-env -iA nixos.gnumake nixos.gdc nixos.python3`)
 
 Automatic deployment
 --------------------
diff --git a/assets/layers/hydrant/barcelona.jpg b/assets/layers/hydrant/barcelona.jpg
new file mode 100644
index 000000000..404248ff4
Binary files /dev/null and b/assets/layers/hydrant/barcelona.jpg differ
diff --git a/assets/layers/hydrant/hydrant.json b/assets/layers/hydrant/hydrant.json
index 0615067b2..f1176762a 100644
--- a/assets/layers/hydrant/hydrant.json
+++ b/assets/layers/hydrant/hydrant.json
@@ -325,6 +325,82 @@
         }
       ]
     },
+    {
+      "id": "hydrant-diameter",
+      "question": {
+        "en": "What is the pipe diameter of this hydrant?"
+      },
+      "freeform": {
+        "key": "fire_hydrant:diameter",
+        "placeholder": {
+          "en": "Pipe diameter"
+        },
+        "type": "int"
+      },
+      "render": {
+        "en": "Pipe diameter: {canonical(fire_hydrant:diameter)}"
+      }
+    },
+    {
+      "id": "hydrant-couplings",
+      "question": {
+        "en": "What kind of couplings does this hydrant have?"
+      },
+      "freeform": {
+        "key": "couplings:type",
+        "placeholder": {
+          "en": "Coupling type"
+        },
+        "type": "string"
+      },
+      "mappings": [
+        {
+          "if": "couplings:type=Storz",
+          "then": {
+            "en": "Storz coupling"
+          },
+          "icon": {
+            "path": "./assets/layers/hydrant/storz.jpg",
+            "class": "large"
+          }
+        },
+        {
+          "if": "couplings:type=UNI",
+          "then": {
+            "en": "UNI coupling"
+          }
+        },
+        {
+          "if": "couplings:type=Barcelona",
+          "then": {
+            "en": "Barcelona coupling"
+          },
+          "icon": {
+            "path": "./assets/layers/hydrant/barcelona.jpg",
+            "class": "large"
+          }
+        }
+      ],
+      "multiAnswer": true,
+      "render": {
+        "en": "Couplings: {couplings:type}"
+      }
+    },
+    {
+      "id": "hydrant-couplings-diameters",
+      "question": {
+        "en": "What diameter are the couplings of this hydrant?"
+      },
+      "freeform": {
+        "key": "couplings:diameters",
+        "placeholder": {
+          "en": "Coupling diameters"
+        }
+      },
+      "render": {
+        "en": "Coupling diameters: {couplings:diameters}"
+      }
+    },
     "images"
   ],
   "presets": [
@@ -375,5 +451,31 @@
         "render": "8"
       }
     }
+  ],
+  "units": [
+    {
+      "applicableUnits": [
+        {
+          "default": true,
+          "canonicalDenomination": "",
+          "alternativeDenomination": [
+            "mm",
+            "millimeter",
+            "millimeters"
+          ],
+          "human": {
+            "en": "millimeters",
+            "nl": "millimeter"
+          },
+          "humanSingular": {
+            "en": "millimeter",
+            "nl": "millimeter"
+          }
+        }
+      ],
+      "appliesToKey": [
+        "fire_hydrant:diameter"
+      ]
+    }
   ]
 }
\ No newline at end of file
diff --git a/assets/layers/hydrant/license_info.json b/assets/layers/hydrant/license_info.json
new file mode 100644
index 000000000..7b01ebaa2
--- /dev/null
+++ b/assets/layers/hydrant/license_info.json
@@ -0,0 +1,22 @@
+[
+  {
+    "path": "barcelona.jpg",
+    "license": "CC-BY-SA",
+    "authors": [
+      "CLIGNER"
+    ],
+    "sources": [
+      "https://commons.wikimedia.org/wiki/File:Gama_racores_UNE23400_ligatura.JPG"
+    ]
+  },
+  {
+    "path": "storz.jpg",
+    "license": "CC-BY-SA",
+    "authors": [
+      "Karl Gruber"
+    ],
+    "sources": [
+      "https://commons.wikimedia.org/wiki/File:Festkupplung.jpg"
+    ]
+  }
+]
\ No newline at end of file
diff --git a/assets/layers/hydrant/storz.jpg b/assets/layers/hydrant/storz.jpg
new file mode 100644
index 000000000..55dc2a5db
Binary files /dev/null and b/assets/layers/hydrant/storz.jpg differ