Sri Lanka River & Flood REST API

public REST API & Server-Sent Events stream for river water levels, rate-of-rise metrics, 24-hour rainfall accumulations, and real-time flood alert push notifications across Sri Lanka river basins.

Base URL: https://slwaterlevel.mevinu.com
Authentication: None required (Public access)
Rate Limit: 60 requests/min per IP (10 connections/min for SSE)

Endpoint Quick Reference

Method	Path	Description	Example (Norwood)
GET	`/api/history/{gauge}/daily`	Daily summaries with min/max peak times	/api/history/Norwood/daily?days=7
GET	`/api/history/{gauge}`	Hourly time-series filtered by days, week, or date	/api/history/Norwood?range=7d&detailed=true
GET	`/api/gauges/{gauge}`	Live station snapshot, rate-of-rise & status	/api/gauges/Norwood
GET	`/api/gauges`	Filterable & sortable list of all stations	/api/gauges?basin=Kelani+Ganga
GET	`/api/alerts`	Active alerts with pre-formatted push notification copy	/api/alerts?level=all
GET	`/api/rainfall/{gauge}`	Accurate 24h & 1h rainfall accumulation (ArcGIS SUM)	/api/rainfall/Norwood
GET	`/api/readings`	Multi-station historical query with time filter	/api/readings?gauge=Norwood&range=1d
SSE	`/stream`	Server-Sent Events real-time broadcast stream	/stream

GET /api/history/{gauge_name}/daily

Returns daily aggregated summaries for each calendar day, including min/max water levels and their exact peak occurrence times, daily rainfall total, average water level, and sample count.

📅 Permanent Retention ⏰ Sri Lanka Local Time (+05:30) 📈 Perfect for Charts & Calendars

Query Parameters

days optional integer Number of previous days to aggregate (default: 14). E.g. 7

range optional string Range alias: 1d, 7d, 14d, 30d, all

date optional string Specific calendar day in YYYY-MM-DD format

curl -s "https://slwaterlevel.mevinu.com/api/history/Norwood/daily?days=7"

const res = await fetch('https://slwaterlevel.mevinu.com/api/history/Norwood/daily?days=7');
const { daily } = await res.json();
daily.forEach(day => {
  console.log(`${day.date}: Min ${day.min_water_level}m at ${day.min_water_level_time}`);
  console.log(`            Max ${day.max_water_level}m at ${day.max_water_level_time}`);
});

import requests

res = requests.get('https://slwaterlevel.mevinu.com/api/history/Norwood/daily?days=7').json()
for day in res.get('daily', []):
    print(f"{day['date']} -> Max: {day['max_water_level']}m @ {day['max_water_level_time']}")

{
  "gauge": "Norwood",
  "days_returned": 2,
  "daily": [
    {
      "date": "2026-10-02",
      "min_water_level": 0.76,
      "min_water_level_time": "2026-10-02T12:03:32+05:30",
      "min_water_level_ts": 1790922812776,
      "max_water_level": 1.25,
      "max_water_level_time": "2026-10-02T19:03:40+05:30",
      "max_water_level_ts": 1790948020805,
      "avg_water_level": 0.932,
      "total_rainfall": 43.8,
      "reading_count": 23
    },
    {
      "date": "2026-10-03",
      "min_water_level": 0.82,
      "min_water_level_time": "2026-10-03T15:02:59+05:30",
      "min_water_level_ts": 1791019979626,
      "max_water_level": 1.24,
      "max_water_level_time": "2026-10-03T21:02:46+05:30",
      "max_water_level_ts": 1791041566761,
      "avg_water_level": 1.027,
      "total_rainfall": 24.4,
      "reading_count": 24
    }
  ]
}

Interactive Test Console Norwood Station

GET /api/history/{gauge_name}

Hourly water level and rainfall time-series with zero auto-pruning. Supports lightweight chart arrays [{t, y, water_level, rain_fall}] or rich mobile detailed mode with thresholds.

Query Parameters

range optional string 1d (24h), 7d (1 week), 14d (2 weeks), 30d, all

detailed optional boolean Set to true to attach metadata, thresholds, coordinates & summary stats

date optional string Filter to single date (YYYY-MM-DD)

curl -s "https://slwaterlevel.mevinu.com/api/history/Norwood?range=7d&detailed=true"

const res = await fetch('https://slwaterlevel.mevinu.com/api/history/Norwood?range=7d&detailed=true');
const data = await res.json();
console.log('Norwood Basin:', data.metadata.basin);
console.log('Peak Level:', data.summary.max_water_level, 'm');

{
  "gauge": "Norwood",
  "metadata": {
    "basin": "Kelani Ganga",
    "alertpull": 1.5,
    "minorpull": 3.0,
    "majorpull": 4.5,
    "current_level": 0.82,
    "status": "normal",
    "coordinates": { "x": 80.6112, "y": 6.84026 }
  },
  "summary": {
    "min_water_level": 0.76,
    "max_water_level": 1.32,
    "avg_water_level": 0.994,
    "total_rainfall": 69.2
  },
  "readings": [
    {
      "ts": 1790922812776,
      "time": "2026-10-02T12:03:32+05:30",
      "water_level": 0.76,
      "rain_fall": 0.0
    }
  ]
}

Interactive Test ConsoleNorwood History

GET /api/gauges/{gauge_name}

Returns live telemetry snapshot for a specific gauge station: current water level, rate-of-rise in m/hr (excluding rainfall), 1-hour and 24-hour rainfall, coordinates, and alert thresholds.

curl -s "https://slwaterlevel.mevinu.com/api/gauges/Norwood"

const res = await fetch('https://slwaterlevel.mevinu.com/api/gauges/Norwood');
const station = await res.json();
console.log(`Station: ${station.gauge} (${station.basin})`);
console.log(`Level: ${station.water_level}m | Status: ${station.status}`);

{
  "gauge": "Norwood",
  "basin": "Kelani Ganga",
  "water_level": 0.82,
  "rate_of_rise": 0.02,
  "is_rising": true,
  "rain_1h": 0.0,
  "rain_24h": 24.4,
  "alertpull": 1.5,
  "minorpull": 3.0,
  "majorpull": 4.5,
  "status": "normal",
  "coordinates": { "lat": 6.84026, "lng": 80.6112 },
  "last_updated": 1791056012112,
  "last_updated_time": "2026-10-04T01:03:32+05:30"
}

Interactive Test ConsoleNorwood Snapshot

GET /api/gauges

Flat REST endpoint for mobile card lists and map marker initialization. Filterable by river basin, flood status, and search keywords.

Query Parameters

basin optional string Filter by river basin (e.g. Kelani Ganga, Kalu Ganga)

status optional string normal, alert, minor_flood, major_flood, or flood

search optional string Keyword search matching station name or river basin (e.g. Norwood)

sort optional string Sort order: name, water_level, rain_24h, status

Interactive Test ConsoleStation Search

GET /api/alerts

Feed designed specifically for real-time mobile push notifications. Returns all stations with active flood stages or rapid water rises, complete with ready-to-dispatch notification.title and notification.body copy.

Query Parameters

level optional string all (default), flood (minor + major), or major

basin optional string Filter alerts to specific river basin

min_ror optional float Only include stations rising faster than N m/hr (e.g. 0.10)

curl -s "https://slwaterlevel.mevinu.com/api/alerts?level=all"

// Example Flutter / React Native background worker:
const res = await fetch('https://slwaterlevel.mevinu.com/api/alerts?level=flood');
const { alerts } = await res.json();

for (const alert of alerts) {
  // Directly forward to Firebase Cloud Messaging (FCM) or Local Notifications:
  sendNotification({
    title: alert.notification.title,
    body: alert.notification.body,
    payload: { gauge: alert.gauge }
  });
}

{
  "total_alerts": 1,
  "server_time": "2026-10-04T01:30:00+05:30",
  "alerts": [
    {
      "gauge": "Norwood",
      "basin": "Kelani Ganga",
      "status": "alert",
      "severity": "medium",
      "water_level": 1.55,
      "alertpull": 1.5,
      "minorpull": 3.0,
      "majorpull": 4.5,
      "rate_of_rise": 0.16,
      "is_rising": true,
      "rain_1h": 8.0,
      "rain_24h": 45.2,
      "alert_reasons": [
        "Alert threshold exceeded (1.55m >= 1.50m)",
        "Rapid water rise (+0.16 m/hr)"
      ],
      "notification": {
        "title": "🔔 FLOOD ALERT: Norwood (Kelani Ganga)",
        "body": "Water level 1.55m. Alert threshold reached (1.55m >= 1.50m) Rapid water rise (+0.16 m/hr)"
      }
    }
  ]
}

Interactive Test ConsoleActive Alerts

GET /api/rainfall/{gauge_name}

Returns accurate 24-hour cumulative rainfall calculated directly via ArcGIS statistical engine aggregation (SUM(rain_fall)), matching the official Department of Irrigation dashboard.

Interactive Test ConsoleNorwood 24h Rain

GET /api/readings

Query readings across single or multiple stations (comma-separated gauge names). Filterable by date or predefined ranges.

Interactive Test ConsoleNorwood Readings (24h)

SSE /stream

Server-Sent Events

Persistent HTTP event stream that immediately broadcasts full gauge updates whenever new data is polled (~15 minutes). Features automatic 30s heartbeats to prevent proxy timeouts.

const es = new EventSource('https://slwaterlevel.mevinu.com/stream');

es.onmessage = (event) => {
  const gauges = JSON.parse(event.data);
  const norwood = gauges.find(g => g.attributes.gauge === 'Norwood');
  if (norwood) {
    console.log('Norwood Updated:', norwood.attributes.water_level, 'm');
  }
};

es.onerror = (err) => console.warn('SSE reconnecting...', err);

import json, sseclient

# pip install sseclient-py
messages = sseclient.SSEClient('https://slwaterlevel.mevinu.com/stream')
for msg in messages:
    if msg.data:
        data = json.loads(msg.data)
        print(f"Received update for {len(data)} stations")

Mobile App Push Alerts Guide

To integrate background flood alerts into your mobile app (Flutter, React Native, iOS, Android):

// In your Flutter background task (e.g. workmanager):
Future<void> checkFloodAlerts() async {
  final url = Uri.parse('https://slwaterlevel.mevinu.com/api/alerts?level=flood');
  final response = await http.get(url);
  if (response.statusCode == 200) {
    final data = jsonDecode(response.body);
    for (var alert in data['alerts']) {
      // Dispatch local notification using flutter_local_notifications:
      flutterLocalNotificationsPlugin.show(
        alert['gauge'].hashCode,
        alert['notification']['title'],
        alert['notification']['body'],
        NotificationDetails(android: AndroidNotificationDetails('flood_alerts', 'Flood Alerts')),
      );
    }
  }
}

// In your React Native background fetch handler:
import notifee from '@notifee/react-native';

async function checkFloodAlerts() {
  const res = await fetch('https://slwaterlevel.mevinu.com/api/alerts?level=flood');
  const { alerts } = await res.json();
  for (const alert of alerts) {
    await notifee.displayNotification({
      title: alert.notification.title,
      body: alert.notification.body,
      android: { channelId: 'flood_alerts' }
    });
  }
}

Flood Thresholds & Conventions

Status	Severity	Condition	Visual Badge
normal	Normal	`water_level < alertpull`	Green
alert	Medium	`alertpull ≤ water_level < minorpull`	Amber
minor_flood	High	`minorpull ≤ water_level < majorpull`	Orange
major_flood	Critical	`water_level ≥ majorpull`	Red

* Timestamps (ts) are Unix epoch milliseconds. Local ISO timestamps are formatted in Sri Lanka timezone (Asia/Colombo, +05:30). Water levels are measured in metres (m), rain in millimetres (mm), and rate of rise in m/hr.