--- a/client/src/store/gauges.js	Fri Aug 30 11:30:11 2019 +0200
+++ b/client/src/store/gauges.js	Fri Aug 30 12:11:35 2019 +0200
@@ -11,9 +11,17 @@
  * Author(s):
  * Markus Kottländer <markus@intevation.de>
  */
+import Vue from "vue";
 import { HTTP } from "@/lib/http";
 import { WFS } from "ol/format";
-import { isPast, startOfDay, endOfDay, format } from "date-fns";
+import {
+  isPast,
+  startOfDay,
+  endOfDay,
+  format,
+  isBefore,
+  addMinutes
+} from "date-fns";
 
 let dateFrom = new Date();
 dateFrom.setDate(dateFrom.getDate() - 30);
@@ -31,6 +39,7 @@
     yearWaterlevels: [],
     nashSutcliffe: null,
     nashSutcliffeOverview: [],
+    nashSutcliffeCache: {},
     dateFrom: dateFrom,
     dateTo: dateTo,
     yearCompare: new Date().getFullYear()
@@ -54,6 +63,13 @@
     }
   },
   mutations: {
+    addNSCtoCache: (state, entry) => {
+      const { isrsCode, nsc, timestamp } = entry;
+      Vue.set(state.nashSutcliffeCache, isrsCode, {
+        nsc,
+        timestamp
+      });
+    },
     gauges: (state, gauges) => {
       state.gauges = gauges;
     },
@@ -100,6 +116,35 @@
     }
   },
   actions: {
+    getNashSutcliffeForISRS: ({ state, commit }, isrsCode) => {
+      return new Promise((resolve, reject) => {
+        const now = new Date();
+        let nashSutcliffe = state.nashSutcliffeCache[isrsCode];
+        if (nashSutcliffe) {
+          const { timestamp, nsc } = nashSutcliffe;
+          const isRecent = isBefore(now, addMinutes(timestamp, 15));
+          if (isRecent) {
+            resolve(nsc);
+            return;
+          }
+        }
+        HTTP.get(`/data/nash-sutcliffe/${isrsCode}`, {
+          headers: { "X-Gemma-Auth": localStorage.getItem("token") }
+        })
+          .then(response => {
+            nashSutcliffe = response.data;
+            commit("addNSCtoCache", {
+              isrsCode,
+              nsc: nashSutcliffe,
+              timestamp: now
+            });
+            resolve(nashSutcliffe);
+          })
+          .catch(error => {
+            reject(error);
+          });
+      });
+    },
     selectedGaugeISRS: ({ commit, dispatch, state }, isrs) => {
       if (state.selectedGaugeISRS !== isrs) {
         commit("selectedGaugeISRS", isrs);