diff --git a/app/src/main/java/com/sf/stormwaterutilityandroid/WQI.java b/app/src/main/java/com/sf/stormwaterutilityandroid/WQI.java
new file mode 100644
index 0000000..813c0dd
--- /dev/null
+++ b/app/src/main/java/com/sf/stormwaterutilityandroid/WQI.java
@@ -0,0 +1,108 @@
+package com.sf.stormwaterutilityandroid;
+
+public class WQI {
+    private double QHEI_substrate_size;
+    private double QHEI_smothering;
+    private double QHEI_silting;
+    private double QHEI_rootwads;
+    private double QHEI_overhanging_veg;
+    private double QHEI_oxbowsblack_waters;
+    private double QHEI_downed_treeslogs;
+    private double QHEI_shallows;
+    private double QHEI_water_plants;
+    private double QHEI_deep_pools;
+    private double QHEI_logswoody_debris;
+    private double QHEI_boulders;
+    private double QHEI_undercut_banks;
+    private double QHEI_sinuosity;
+    private double QHEI_natural;
+    private double QHEI_riparian_width;
+    private double QHEI_land_use;
+    private double QHEI_bank_erosion;
+    private double QHEI_stream_shading;
+    private double QHEI_deepest_pool;
+    private double QHEI_velocity;
+    private double QHEI_rifflerun_depth;
+    private double QHEI_rifflerun_substrate;
+
+    //constructor
+    WQI(double QHEI_substrate_size, double QHEI_smothering, double QHEI_silting, double QHEI_rootwads, double QHEI_overhanging_veg,
+    double QHEI_oxbowsblack_waters, double QHEI_downed_treeslogs, double QHEI_shallows, double QHEI_water_plants, double QHEI_logswoody_debris,
+        double QHEI_boulders, double QHEI_undercut_banks, double QHEI_sinuosity, double QHEI_natural, double QHEI_riparian_width,
+        double QHEI_land_use, double QHEI_bank_erosion, double QHEI_stream_shading, double QHEI_deepest_pool, double QHEI_velocity,
+        double QHEI_rifflerun_depth, double QHEI_rifflerun_substrate, double QHEI_deep_pools) {
+
+        this.QHEI_substrate_size = QHEI_substrate_size;
+        this.QHEI_smothering = QHEI_smothering;
+        this.QHEI_silting = QHEI_silting;
+        this.QHEI_rootwads = QHEI_rootwads;
+        this.QHEI_overhanging_veg = QHEI_overhanging_veg;
+        this.QHEI_oxbowsblack_waters = QHEI_oxbowsblack_waters;
+        this.QHEI_downed_treeslogs = QHEI_downed_treeslogs;
+        this.QHEI_shallows = QHEI_shallows;
+        this.QHEI_water_plants = QHEI_water_plants;
+        this.QHEI_logswoody_debris = QHEI_logswoody_debris;
+        this.QHEI_boulders = QHEI_boulders;
+        this.QHEI_undercut_banks = QHEI_undercut_banks;
+        this.QHEI_sinuosity = QHEI_sinuosity;
+        this.QHEI_natural = QHEI_natural;
+        this.QHEI_riparian_width = QHEI_riparian_width;
+        this.QHEI_land_use = QHEI_land_use;
+        this.QHEI_bank_erosion = QHEI_bank_erosion;
+        this.QHEI_stream_shading = QHEI_stream_shading;
+        this.QHEI_deepest_pool = QHEI_deepest_pool;
+        this.QHEI_velocity = QHEI_velocity;
+        this.QHEI_rifflerun_depth = QHEI_rifflerun_depth;
+        this.QHEI_rifflerun_substrate = QHEI_rifflerun_substrate;
+        this.QHEI_deep_pools = QHEI_deep_pools;
+    }
+
+    WQI()
+    {
+        QHEI_substrate_size = 0;
+        QHEI_smothering = 0;
+        QHEI_silting = 0;
+        QHEI_rootwads = 0;
+        QHEI_overhanging_veg = 0;
+        QHEI_oxbowsblack_waters = 0;
+        QHEI_downed_treeslogs = 0;
+        QHEI_shallows = 0;
+        QHEI_water_plants = 0;
+        QHEI_deep_pools = 0;
+        QHEI_logswoody_debris = 0;
+        QHEI_boulders = 0;
+        QHEI_undercut_banks = 0;
+        QHEI_sinuosity = 0;
+        QHEI_natural = 0;
+        QHEI_riparian_width = 0;
+        QHEI_land_use = 0;
+        QHEI_bank_erosion = 0;
+        QHEI_stream_shading = 0;
+        QHEI_deepest_pool = 0;
+        QHEI_velocity = 0;
+        QHEI_rifflerun_depth = 0;
+        QHEI_rifflerun_substrate = 0;
+    }
+
+    public double calculate_WQI() {
+        return QHEI_substrate_size + QHEI_smothering + QHEI_silting + QHEI_rootwads + QHEI_overhanging_veg +
+                QHEI_oxbowsblack_waters + QHEI_downed_treeslogs + QHEI_shallows + QHEI_water_plants + QHEI_deep_pools +
+                QHEI_logswoody_debris + QHEI_boulders + QHEI_undercut_banks + 2 * (QHEI_sinuosity + QHEI_natural) +
+                QHEI_riparian_width + QHEI_land_use + QHEI_bank_erosion + QHEI_stream_shading + QHEI_deepest_pool +
+                QHEI_velocity + QHEI_rifflerun_depth + QHEI_rifflerun_substrate;
+    }
+
+    public static double get_WQI(double QHEI_substrate_size, double QHEI_smothering, double QHEI_silting, double QHEI_rootwads, double QHEI_overhanging_veg,
+                                 double QHEI_oxbowsblack_waters, double QHEI_downed_treeslogs, double QHEI_shallows, double QHEI_water_plants, double QHEI_logswoody_debris,
+                                 double QHEI_boulders, double QHEI_undercut_banks, double QHEI_sinuosity, double QHEI_natural, double QHEI_riparian_width,
+                                 double QHEI_land_use, double QHEI_bank_erosion, double QHEI_stream_shading, double QHEI_deepest_pool, double QHEI_velocity,
+                                 double QHEI_rifflerun_depth, double QHEI_rifflerun_substrate, double QHEI_deep_pools)
+    {
+        return QHEI_substrate_size + QHEI_smothering + QHEI_silting + QHEI_rootwads + QHEI_overhanging_veg +
+                QHEI_oxbowsblack_waters + QHEI_downed_treeslogs + QHEI_shallows + QHEI_water_plants + QHEI_deep_pools +
+                QHEI_logswoody_debris + QHEI_boulders + QHEI_undercut_banks + 2 * (QHEI_sinuosity + QHEI_natural) +
+                QHEI_riparian_width + QHEI_land_use + QHEI_bank_erosion + QHEI_stream_shading + QHEI_deepest_pool +
+                QHEI_velocity + QHEI_rifflerun_depth + QHEI_rifflerun_substrate;
+    }
+
+}