diff --git a/src/components/ProjectMap/index.tsx b/src/components/ProjectMap/index.tsx
index 4c33b69b..0ccfa27a 100644
--- a/src/components/ProjectMap/index.tsx
+++ b/src/components/ProjectMap/index.tsx
@@ -1,4 +1,9 @@
-import React, { useRef, useCallback } from 'react';
+import React, {
+    useRef,
+    useState,
+    useEffect,
+    useCallback,
+} from 'react';
 import {
     MapContainer,
     TileLayer,
@@ -11,17 +16,45 @@ import GestureHandler from 'components/LeafletGestureHandler';
 interface Props {
     className?: string;
     children?: React.ReactNode;
-    geoJSON: GeoJSON.FeatureCollection<GeoJSON.Polygon>;
+    // NOTE: URL to a GeoJSON file which the map fetches and renders. fetch
+    // supports data: URLs too, so a client-built fallback can be passed the
+    // same way as a real file URL.
+    geoJsonUrl: string;
 }
 
 function ProjectMap(props: Props) {
     const {
         className,
         children,
-        geoJSON,
+        geoJsonUrl,
     } = props;
 
     const mapRef = useRef<Map>(null);
+    const [geoJson, setGeoJson] = useState<GeoJSON.GeoJsonObject>();
+
+    useEffect(() => {
+        // NOTE: Handle component dismount gracefully
+        let active = true;
+
+        async function loadGeoJson(url: string) {
+            try {
+                const res = await fetch(url);
+                const data = await res.json();
+                if (active) {
+                    setGeoJson(data);
+                }
+            } catch (err) {
+                // eslint-disable-next-line no-console
+                console.error('Failed fetching map GeoJSON', url, err);
+            }
+        }
+
+        loadGeoJson(geoJsonUrl);
+
+        return () => {
+            active = false;
+        };
+    }, [geoJsonUrl]);
 
     const handleGeoJSONAdd = useCallback(
         (layer: LayerEvent) => {
@@ -43,19 +76,24 @@ function ProjectMap(props: Props) {
             minZoom={1}
             worldCopyJump
         >
-            <GeoJSON
-                data={geoJSON}
-                eventHandlers={{
-                    add: handleGeoJSONAdd,
-                }}
-                pathOptions={{
-                    fillColor: '#AABE5D',
-                    color: '#AABE5D',
-                    weight: 2,
-                    opacity: 1,
-                    fillOpacity: 0.1,
-                }}
-            />
+            {geoJson && (
+                <GeoJSON
+                    // NOTE: react-leaflet's GeoJSON only reads `data` on mount,
+                    // so key it to the source to remount when the data changes.
+                    key={geoJsonUrl}
+                    data={geoJson}
+                    eventHandlers={{
+                        add: handleGeoJSONAdd,
+                    }}
+                    pathOptions={{
+                        fillColor: '#AABE5D',
+                        color: '#AABE5D',
+                        weight: 2,
+                        opacity: 1,
+                        fillOpacity: 0.1,
+                    }}
+                />
+            )}
             <GestureHandler />
             <TileLayer
                 attribution='&copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors &copy; <a href="https://carto.com/attributions">CARTO</a>'
diff --git a/src/pages/[locale]/projects/[id].tsx b/src/pages/[locale]/projects/[id].tsx
index 2c3c1886..6af35684 100644
--- a/src/pages/[locale]/projects/[id].tsx
+++ b/src/pages/[locale]/projects/[id].tsx
@@ -503,11 +503,11 @@ function Project(props: Props) {
                     })
                 )}
             >
-                {aoiGeometryFeature && (
+                {aoiDownload && (
                     <div className={styles.mapContainer}>
                         <DynamicProjectMap
                             className={styles.projectsMap}
-                            geoJSON={aoiGeometryFeature}
+                            geoJsonUrl={aoiDownload.url}
                         />
                     </div>
                 )}