--- a/pkg/controllers/bottlenecks.go	Sun Apr 28 22:03:37 2019 +0200
+++ b/pkg/controllers/bottlenecks.go	Sun Apr 28 22:26:48 2019 +0200
@@ -97,6 +97,13 @@
 	availMeasurements []availMeasurement
 )
 
+// afdRefs are the typical available fairway depth reference values.
+var afdRefs = []referenceValue{
+	{0, 200},
+	{1, 230},
+	{2, 250},
+}
+
 func (measurement *availMeasurement) getDepth() float64 {
 	return float64(measurement.depth)
 }
@@ -242,6 +249,18 @@
 	return t.UTC(), nil
 }
 
+func parseInt(s, what string) (int, error) {
+	i, err := strconv.Atoi(s)
+	if err != nil {
+		return 0, JSONError{
+			Code: http.StatusBadRequest,
+			Message: fmt.Sprintf(
+				"Invalid value for field '%s': %v", what, err),
+		}
+	}
+	return i, nil
+}
+
 func loadDepthValues(
 	ctx context.Context,
 	conn *sql.Conn,
@@ -370,11 +389,7 @@
 
 	var los int
 	if l := req.FormValue("los"); l != "" {
-		if los, err = strconv.Atoi(l); err != nil {
-			err = JSONError{
-				Code:    http.StatusBadRequest,
-				Message: fmt.Sprintf("Invalid value for field 'los': %v", err),
-			}
+		if los, err = parseInt(l, "los"); err != nil {
 			return
 		}
 	} else {
@@ -415,12 +430,6 @@
 		(*availMeasurement).getValue,
 	)
 
-	afdRefs := []referenceValue{
-		{0, 200},
-		{1, 230},
-		{2, 250},
-	}
-
 	afd := ms.classifyAvailMeasurements(
 		from, to,
 		afdRefs,
@@ -475,3 +484,76 @@
 	jr = JSONResult{Result: &out}
 	return
 }
+
+func bottleneckAvailableFairwayDepth(
+	_ interface{},
+	req *http.Request,
+	conn *sql.Conn,
+) (jr JSONResult, err error) {
+	bn := mux.Vars(req)["objnam"]
+
+	if bn == "" {
+		err = JSONError{
+			Code:    http.StatusBadRequest,
+			Message: "Missing objnam of bottleneck",
+		}
+		return
+	}
+
+	var mode int
+	if m := req.FormValue("mode"); m != "" {
+		switch strings.ToLower(m) {
+		case "monthly":
+			mode = 0
+		case "quarterly":
+			mode = 1
+		case "yearly":
+			mode = 2
+		default:
+			err = JSONError{
+				Code:    http.StatusBadRequest,
+				Message: "Unknown 'mode' value",
+			}
+			return
+		}
+	}
+
+	var from, to time.Time
+
+	if f := req.FormValue("from"); f != "" {
+		if from, err = parseTime(f, "from"); err != nil {
+			return
+		}
+	} else {
+		from = time.Now().AddDate(-1, 0, 0).UTC()
+	}
+
+	if t := req.FormValue("to"); t != "" {
+		if to, err = parseTime(t, "to"); err != nil {
+			return
+		}
+	} else {
+		to = from.AddDate(1, 0, 0).UTC()
+	}
+
+	if to.Before(from) {
+		to, from = from, to
+	}
+
+	log.Printf("info: time interval: (%v - %v)\n", from, to)
+
+	var los int
+	if l := req.FormValue("los"); l != "" {
+		if los, err = parseInt(l, "los"); err != nil {
+			return
+		}
+	} else {
+		los = 1
+	}
+
+	// TODO: Implement me!
+
+	_, _ = los, mode
+
+	return
+}

--- a/pkg/controllers/routes.go	Sun Apr 28 22:03:37 2019 +0200
+++ b/pkg/controllers/routes.go	Sun Apr 28 22:26:48 2019 +0200
@@ -307,6 +307,10 @@
 		Handle: bottleneckAvailabilty,
 	})).Methods(http.MethodGet)
 
+	api.Handle("/data/bottleneck/fairway-depth/{objnam}", any(&JSONHandler{
+		Handle: bottleneckAvailableFairwayDepth,
+	})).Methods(http.MethodGet)
+
 	api.Handle("/data/waterlevels/{gauge}", any(
 		middleware.DBConn(http.HandlerFunc(waterlevels)))).Methods(http.MethodGet)