diff --git a/src/index.html b/src/index.html
index 5d9cf35a..8896a2e6 100644
--- a/src/index.html
+++ b/src/index.html
@@ -8469,7 +8469,6 @@
 
     <script defer src="config/heightmap-templates.js"></script>
     <script defer src="config/precreated-heightmaps.js"></script>
-    <script defer src="modules/lakes.js?v=1.99.00"></script>
     <script defer src="modules/names-generator.js?v=1.106.0"></script>
     <script defer src="modules/cultures-generator.js?v=1.106.0"></script>
     <script defer src="modules/burgs-generator.js?v=1.109.5"></script>
diff --git a/src/modules/PackedGraph.ts b/src/modules/PackedGraph.ts
index 1430c860..d6295430 100644
--- a/src/modules/PackedGraph.ts
+++ b/src/modules/PackedGraph.ts
@@ -1,22 +1,27 @@
 import { PackedGraphFeature } from "./features";
 import { River } from "./river-generator";
 
+
+type TypedArray = Uint8Array | Uint16Array | Uint32Array | Int8Array | Int16Array | Float32Array | Float64Array;
+
 export interface PackedGraph {
   cells: {
     i: number[]; // cell indices
     c: number[][]; // neighboring cells
     v: number[][]; // neighboring vertices
+    p: [number, number][]; // cell polygon points
     b: boolean[]; // cell is on border
-    h: Uint8Array; // cell heights
-    t: Uint8Array; // cell terrain types
+    h: TypedArray; // cell heights
+    t: TypedArray; // cell terrain types
     r: Uint16Array; // river id passing through cell
     f: Uint16Array; // feature id occupying cell
-    fl: Uint16Array | Uint8Array; // flux presence in cell
-    conf: Uint16Array | Uint8Array; // cell water confidence
-    haven: Uint8Array; // cell is a haven
+    fl: TypedArray; // flux presence in cell
+    conf: TypedArray; // cell water confidence
+    haven: TypedArray; // cell is a haven
     g: number[]; // cell ground type
     culture: number[]; // cell culture id
-    p: [number, number][]; // cell polygon points
+    biome: TypedArray; // cell biome id
+    harbor: TypedArray; // cell harbour presence
   };
   vertices: {
     i: number[]; // vertex indices
@@ -24,6 +29,7 @@ export interface PackedGraph {
     v: number[][]; // neighboring vertices
     x: number[]; // x coordinates
     y: number[]; // y coordinates
+    p: [number, number][]; // vertex points
   };
   rivers: River[];
   features: PackedGraphFeature[];
diff --git a/src/modules/biomes.ts b/src/modules/biomes.ts
index 49bc24b8..ba6e58a9 100644
--- a/src/modules/biomes.ts
+++ b/src/modules/biomes.ts
@@ -1,10 +1,11 @@
 import { range, mean } from "d3";
 import { rn } from "../utils";
+import { PackedGraph } from "./PackedGraph";
 
 declare global {
   var Biomes: BiomesModule;
 
-  var pack: any;
+  var pack: PackedGraph;
   var grid: any;
   var TIME: boolean;
 
diff --git a/src/modules/features.ts b/src/modules/features.ts
index 75367278..e6b935c6 100644
--- a/src/modules/features.ts
+++ b/src/modules/features.ts
@@ -1,15 +1,17 @@
 import { clipPoly, connectVertices, createTypedArray, distanceSquared, isLand, isWater, rn, TYPED_ARRAY_MAX_VALUES,unique } from "../utils";
 import Alea from "alea";
 import { polygonArea } from "d3";
+import { LakesModule } from "./lakes";
+import { PackedGraph } from "./PackedGraph";
 
 declare global {
   interface Window {
     Features: any;
   }
   var TIME: boolean;
-  var Lakes: any;
+  var Lakes: LakesModule;
   var grid: any;
-  var pack: any;
+  var pack: PackedGraph;
   var seed: string;
 }
 
@@ -30,11 +32,15 @@ export interface PackedGraphFeature {
   temp: number;
   flux: number;
   evaporation: number;
-  inlets: number[];
-  outlet: number;
-  river: number;
-  enteringFlux: number;
-  closed: boolean;
+  name: string;
+
+  // River related
+  inlets?: number[];
+  outlet?: number;
+  river?: number;
+  enteringFlux?: number;
+  closed?: boolean;
+  outCell?: number;
 }
 
 export interface GridFeature {
@@ -210,7 +216,7 @@ class FeatureModule {
       if (type === "lake") {
         if (area > 0) feature.vertices = (feature.vertices as number[]).reverse();
         feature.shoreline = unique((feature.vertices as number[]).map(vertex => vertices.c[vertex].filter((index: number) => isLand(index, this.packedGraph))).flat() || []);
-        feature.height = Lakes.getHeight(feature);
+        feature.height = Lakes.getHeight(feature as PackedGraphFeature);
       }
 
       return {
@@ -278,7 +284,7 @@ class FeatureModule {
     this.packedGraph.cells.f = featureIds;
     this.packedGraph.cells.haven = haven;
     this.packedGraph.cells.harbor = harbor;
-    this.packedGraph.features = [0, ...features];
+    this.packedGraph.features = [0 as unknown as PackedGraphFeature, ...features];
 
     TIME && console.timeEnd("markupPack");
   }
diff --git a/src/modules/index.ts b/src/modules/index.ts
index 21836080..c15b421a 100644
--- a/src/modules/index.ts
+++ b/src/modules/index.ts
@@ -1,6 +1,7 @@
 import "./voronoi";
 import "./heightmap-generator";
 import "./features";
+import "./lakes";
 import "./ocean-layers";
 import "./river-generator";
 import "./biomes"
\ No newline at end of file
diff --git a/public/modules/lakes.js b/src/modules/lakes.ts
similarity index 65%
rename from public/modules/lakes.js
rename to src/modules/lakes.ts
index 8ce18793..1665a3ab 100644
--- a/public/modules/lakes.js
+++ b/src/modules/lakes.ts
@@ -1,12 +1,98 @@
-"use strict";
+import { PackedGraphFeature } from "./features";
+import { min, mean } from "d3";
+import { byId,
+rn } from "../utils";
+import { PackedGraph } from "./PackedGraph";
 
-window.Lakes = (function () {
-  const LAKE_ELEVATION_DELTA = 0.1;
+declare global {
+  var Lakes: LakesModule;
+  var pack: PackedGraph;
+  var Names: any;
+
+  var heightExponentInput: HTMLInputElement;
+}
+
+export class LakesModule {
+  private LAKE_ELEVATION_DELTA = 0.1;
+
+  getHeight(feature: PackedGraphFeature) {
+    const heights = pack.cells.h;
+    const minShoreHeight = min(feature.shoreline.map(cellId => heights[cellId])) || 20;
+    return rn(minShoreHeight - this.LAKE_ELEVATION_DELTA, 2);
+  };
+
+  defineNames() {
+    pack.features.forEach((feature: PackedGraphFeature) => {
+      if (feature.type !== "lake") return;
+      feature.name = this.getName(feature);
+    });
+  };
+
+  getName(feature: PackedGraphFeature): string {
+    const landCell = feature.shoreline[0];
+    const culture = pack.cells.culture[landCell];
+    return Names.getCulture(culture);
+  };
+
+  cleanupLakeData = function () {
+    for (const feature of pack.features) {
+      if (feature.type !== "lake") continue;
+      delete feature.river;
+      delete feature.enteringFlux;
+      delete feature.outCell;
+      delete feature.closed;
+      feature.height = rn(feature.height, 3);
+
+      const inlets = feature.inlets?.filter(r => pack.rivers.find(river => river.i === r));
+      if (!inlets || !inlets.length) delete feature.inlets;
+      else feature.inlets = inlets;
+
+      const outlet = feature.outlet && pack.rivers.find(river => river.i === feature.outlet);
+      if (!outlet) delete feature.outlet;
+    }
+  };
+
+  defineClimateData(heights: Uint8Array) {
+    const {cells, features} = pack;
+    const lakeOutCells = new Uint16Array(cells.i.length);
+    
+    const getFlux = (lake: PackedGraphFeature) => {
+      return lake.shoreline.reduce((acc, c) => acc + grid.cells.prec[cells.g[c]], 0);
+    }
+
+    const getLakeTemp = (lake: PackedGraphFeature) => {
+      if (lake.cells < 6) return grid.cells.temp[cells.g[lake.firstCell]];
+      return rn(mean(lake.shoreline.map(c => grid.cells.temp[cells.g[c]])) as number, 1);
+    }
+
+    const getLakeEvaporation = (lake: PackedGraphFeature) => {
+      const height = (lake.height - 18) ** Number(heightExponentInput.value); // height in meters
+      const evaporation = ((700 * (lake.temp + 0.006 * height)) / 50 + 75) / (80 - lake.temp); // based on Penman formula, [1-11]
+      return rn(evaporation * lake.cells);
+    }
+
+    const getLowestShoreCell = (lake: PackedGraphFeature) => {
+      return lake.shoreline.sort((a, b) => heights[a] - heights[b])[0];
+    }
+
+    features.forEach(feature => {
+      if (feature.type !== "lake") return;
+      feature.flux = getFlux(feature);
+      feature.temp = getLakeTemp(feature);
+      feature.evaporation = getLakeEvaporation(feature);
+      if (feature.closed) return; // no outlet for lakes in depressed areas
+
+      feature.outCell = getLowestShoreCell(feature);
+      lakeOutCells[feature.outCell as number] = feature.i;
+    });
+
+    return lakeOutCells;
+  };
 
   // check if lake can be potentially open (not in deep depression)
-  const detectCloseLakes = h => {
+  detectCloseLakes(h: Uint8Array) {
     const {cells} = pack;
-    const ELEVATION_LIMIT = +byId("lakeElevationLimitOutput").value;
+    const ELEVATION_LIMIT = +(byId("lakeElevationLimitOutput") as HTMLInputElement)?.value;
 
     pack.features.forEach(feature => {
       if (feature.type !== "lake") return;
@@ -25,7 +111,7 @@ window.Lakes = (function () {
       checked[lowestShorelineCell] = true;
 
       while (queue.length && isDeep) {
-        const cellId = queue.pop();
+        const cellId: number = queue.pop() as number;
 
         for (const neibCellId of cells.c[cellId]) {
           if (checked[neibCellId]) continue;
@@ -44,80 +130,6 @@ window.Lakes = (function () {
       feature.closed = isDeep;
     });
   };
+}
 
-  const defineClimateData = function (heights) {
-    const {cells, features} = pack;
-    const lakeOutCells = new Uint16Array(cells.i.length);
-
-    features.forEach(feature => {
-      if (feature.type !== "lake") return;
-      feature.flux = getFlux(feature);
-      feature.temp = getLakeTemp(feature);
-      feature.evaporation = getLakeEvaporation(feature);
-      if (feature.closed) return; // no outlet for lakes in depressed areas
-
-      feature.outCell = getLowestShoreCell(feature);
-      lakeOutCells[feature.outCell] = feature.i;
-    });
-
-    return lakeOutCells;
-
-    function getFlux(lake) {
-      return lake.shoreline.reduce((acc, c) => acc + grid.cells.prec[cells.g[c]], 0);
-    }
-
-    function getLakeTemp(lake) {
-      if (lake.cells < 6) return grid.cells.temp[cells.g[lake.firstCell]];
-      return rn(d3.mean(lake.shoreline.map(c => grid.cells.temp[cells.g[c]])), 1);
-    }
-
-    function getLakeEvaporation(lake) {
-      const height = (lake.height - 18) ** heightExponentInput.value; // height in meters
-      const evaporation = ((700 * (lake.temp + 0.006 * height)) / 50 + 75) / (80 - lake.temp); // based on Penman formula, [1-11]
-      return rn(evaporation * lake.cells);
-    }
-
-    function getLowestShoreCell(lake) {
-      return lake.shoreline.sort((a, b) => heights[a] - heights[b])[0];
-    }
-  };
-
-  const cleanupLakeData = function () {
-    for (const feature of pack.features) {
-      if (feature.type !== "lake") continue;
-      delete feature.river;
-      delete feature.enteringFlux;
-      delete feature.outCell;
-      delete feature.closed;
-      feature.height = rn(feature.height, 3);
-
-      const inlets = feature.inlets?.filter(r => pack.rivers.find(river => river.i === r));
-      if (!inlets || !inlets.length) delete feature.inlets;
-      else feature.inlets = inlets;
-
-      const outlet = feature.outlet && pack.rivers.find(river => river.i === feature.outlet);
-      if (!outlet) delete feature.outlet;
-    }
-  };
-
-  const getHeight = function (feature) {
-    const heights = pack.cells.h;
-    const minShoreHeight = d3.min(feature.shoreline.map(cellId => heights[cellId])) || 20;
-    return rn(minShoreHeight - LAKE_ELEVATION_DELTA, 2);
-  };
-
-  const defineNames = function () {
-    pack.features.forEach(feature => {
-      if (feature.type !== "lake") return;
-      feature.name = getName(feature);
-    });
-  };
-
-  const getName = function (feature) {
-    const landCell = feature.shoreline[0];
-    const culture = pack.cells.culture[landCell];
-    return Names.getCulture(culture);
-  };
-
-  return {defineClimateData, cleanupLakeData, detectCloseLakes, getHeight, defineNames, getName};
-})();
+window.Lakes = new LakesModule();
\ No newline at end of file
diff --git a/src/modules/river-generator.ts b/src/modules/river-generator.ts
index 98a567fd..7a6ed447 100644
--- a/src/modules/river-generator.ts
+++ b/src/modules/river-generator.ts
@@ -7,6 +7,7 @@ rn,round,
 rw} from "../utils";
 import { PackedGraphFeature } from "./features";
 import { PackedGraph } from "./PackedGraph";
+import { LakesModule } from "./lakes";
 
 declare global {
   interface Window {
@@ -16,7 +17,7 @@ declare global {
   var WARN: boolean;
   var graphHeight: number;
   var graphWidth: number;
-  var pack: any;
+  var pack: PackedGraph;
 
   var rivers: Selection<SVGElement, unknown, null, undefined>;
   var pointsInput: HTMLInputElement;
@@ -25,7 +26,7 @@ declare global {
   var TIME: boolean;
 
   var Names: any;
-  var Lakes: any;
+  var Lakes: LakesModule;
 }
 
 export interface River {
@@ -114,8 +115,8 @@ class RiverModule {
             const sameRiver = cells.c[lakeCell].some((c: number) => cells.r[c] === lake.river);
 
             if (sameRiver) {
-              cells.r[lakeCell] = lake.river;
-              addCellToRiver(lakeCell, lake.river);
+              cells.r[lakeCell] = lake.river as number;
+              addCellToRiver(lakeCell, lake.river as number);
             } else {
               cells.r[lakeCell] = riverNext;
               addCellToRiver(lakeCell, riverNext);
@@ -132,7 +133,7 @@ class RiverModule {
         for (const lake of lakes) {
           if (!Array.isArray(lake.inlets)) continue;
           for (const inlet of lake.inlets) {
-            riverParents[inlet] = outlet;
+            riverParents[inlet] = outlet as number;
           }
         }
 
@@ -199,7 +200,7 @@ class RiverModule {
         // pour water to the water body
         const waterBody = features[cells.f[toCell]];
         if (waterBody.type === "lake") {
-          if (!waterBody.river || fromFlux > waterBody.enteringFlux) {
+          if (!waterBody.river || fromFlux > (waterBody.enteringFlux as number)) {
             waterBody.river = river;
             waterBody.enteringFlux = fromFlux;
           }
@@ -320,16 +321,16 @@ class RiverModule {
     TIME && console.timeEnd("generateRivers");
   };
 
-  alterHeights() {
+  alterHeights(): Uint8Array {
     const {h, c, t} = this.pack.cells as {h: Uint8Array, c: number[][], t: Uint8Array};
-    return Array.from(h).map((h, i) => {
+    return Uint8Array.from(Array.from(h).map((h, i) => {
       if (h < 20 || t[i] < 1) return h;
       return h + t[i] / 100 + (mean(c[i].map(c => t[c])) || 0) / 10000;
-    });
+    }));
   };
 
   // depression filling algorithm (for a correct water flux modeling)
-  resolveDepressions(h: number[]) {
+  resolveDepressions(h: Uint8Array) {
     const {cells, features} = this.pack;
     const maxIterations = +(document.getElementById("resolveDepressionsStepsOutput") as HTMLInputElement)?.value;
     const checkLakeMaxIteration = maxIterations * 0.85;
diff --git a/src/utils/polyfills.ts b/src/utils/polyfills.ts
index 18f5f1bd..89a0d2d9 100644
--- a/src/utils/polyfills.ts
+++ b/src/utils/polyfills.ts
@@ -44,7 +44,7 @@ declare global {
   }
 
   interface Array<T> {
-    flat(depth?: number): T[];
+    flat(depth?: number): T;
     at(index: number): T | undefined;
   }