diff --git a/index.css b/index.css
index b8572a14..f1159de9 100644
--- a/index.css
+++ b/index.css
@@ -190,6 +190,12 @@ a {
 #cults {
   stroke-linejoin: round;
   fill-rule: evenodd;
+}
+
+#statesBody,
+#provincesBody,
+#relig,
+#cults {
   mask: url(#land);
 }
 
diff --git a/modules/river-generator.js b/modules/river-generator.js
index f090616a..a17cff87 100644
--- a/modules/river-generator.js
+++ b/modules/river-generator.js
@@ -33,11 +33,12 @@ window.Rivers = (function () {
     function drainWater() {
       const MIN_FLUX_TO_FORM_RIVER = 30;
       const prec = grid.cells.prec;
+      const area = pack.cells.area;
       const land = cells.i.filter(i => h[i] >= 20).sort((a, b) => h[b] - h[a]);
       const lakeOutCells = Lakes.setClimateData(h);
 
       land.forEach(function (i) {
-        cells.fl[i] += prec[cells.g[i]]; // add flux from precipitation
+        cells.fl[i] += prec[cells.g[i]] * area[i] / 100; // add flux from precipitation
 
         // create lake outlet if lake is not in deep depression and flux > evaporation
         const lakes = lakeOutCells[i] ? features.filter(feature => i === feature.outCell && feature.flux > feature.evaporation) : [];
diff --git a/modules/ui/tools.js b/modules/ui/tools.js
index 8783fded..643cf8ac 100644
--- a/modules/ui/tools.js
+++ b/modules/ui/tools.js
@@ -117,6 +117,7 @@ function regenerateRivers() {
   Lakes.defineGroup();
   Rivers.specify();
   if (!layerIsOn("toggleRivers")) toggleRivers();
+  else drawRivers();
 }
 
 function recalculatePopulation() {
diff --git a/modules/voronoi.js b/modules/voronoi.js
index f5e4b45c..19581c9d 100644
--- a/modules/voronoi.js
+++ b/modules/voronoi.js
@@ -2,7 +2,7 @@ class Voronoi {
   /**
    * Creates a Voronoi diagram from the given Delaunator, a list of points, and the number of points. The Voronoi diagram is constructed using (I think) the {@link https://en.wikipedia.org/wiki/Bowyer%E2%80%93Watson_algorithm |Bowyer-Watson Algorithm}
    * The {@link https://github.com/mapbox/delaunator/ |Delaunator} library uses {@link https://en.wikipedia.org/wiki/Doubly_connected_edge_list |half-edges} to represent the relationship between points and triangles.
-   * @param {{triangles: Uint32Array, halfedges: Int32Array}} delaunay A {@link https://github.com/mapbox/delaunator/blob/master/index.js |Delaunator} instance. 
+   * @param {{triangles: Uint32Array, halfedges: Int32Array}} delaunay A {@link https://github.com/mapbox/delaunator/blob/master/index.js |Delaunator} instance.
    * @param {[number, number][]} points A list of coordinates.
    * @param {number} pointsN The number of points.
    */
@@ -15,7 +15,7 @@ class Voronoi {
 
     // Half-edges are the indices into the delaunator outputs:
     // delaunay.triangles[e] gives the point ID where the half-edge starts
-    // delaunay.triangles[e] returns either the opposite half-edge in the adjacent triangle, or -1 if there's not an adjacent triangle.
+    // delaunay.halfedges[e] returns either the opposite half-edge in the adjacent triangle, or -1 if there's not an adjacent triangle.
     for (let e = 0; e < this.delaunay.triangles.length; e++) {
 
       const p = this.delaunay.triangles[this.nextHalfedge(e)];
@@ -132,4 +132,4 @@ class Voronoi {
       Math.floor(1 / D * (ad * (cx - bx) + bd * (ax - cx) + cd * (bx - ax)))
     ];
   }
-}
\ No newline at end of file
+}