River Watchers

What is River Watchers?

River Watchers is a collaborative project between River Cleanup and VITO (Flemish Institute for Technological Research). We use smartphones and artificial intelligence to identify where litter is located. Everyone is invited to take photos of litter—preferably along rivers or other waterways, but you can take photos anywhere. Artificial intelligence helps identify the type of waste in the images. This information is added to an interactive map, creating a detailed overview of pollution in your area—a valuable resource for cleanup efforts and policymakers alike.
You decide where, when, and for how long you participate. Below, you'll find instructions on how to take photos so the AI can accurately identify the type of trash you've found.
Every observation counts!

Upload pictures

Join us and make a difference!

Between June 26 and September 20 (World Cleanup Day), take as many photos as possible of litter—along waterways, in parks, on streets... anywhere in your neighborhood—and help map the problem. By collecting data, we can better understand what types of waste are found in nature and work together on a structural solution.

For every photo you upload, you earn one Trash Token (TT). The more tokens you collect, the higher you’ll rank on the leaderboard. The higher your rank, the better your chances of winning great prizes!

Earn double tokens by detecting litter in our focus zones. These zones are marked with a yellow glow on the litter map.

Why should you participate?

Create impact: Every observation helps tackle pollution.
Local & accessible: Participate whenever and wherever it suits you.
Contribute to science: Your data supports research and policy-making.
Get a chance to win great prizes!

How does it work?

1. Find litter 🔎

Walk along a riverbank, waterway, in the park, or on the street—wherever you like. See litter? Take out your smartphone.

2. Take photos and upload them 📷

Check if your location settings are turned on. Further down this page, you’ll find additional instructions on how to enable them.
Take clear photos of the litter, without people, names, license plates, etc. Then upload your photos via the website.

3. Confirm your upload 📍

Confirm your upload via the confirmation email. Once confirmed, your photos will appear as a dot on the litter map. Every dot counts!

To help the artificial intelligence do its job properly, it’s important to take clear photos. Take the pictures from hip height and directly above the litter. A slight angle is fine if it makes the litter more recognizable.

Below, you’ll find some practical tips for taking good photos.
Further down this page, there’s also a handy infographic explaining how to take the ideal photos for River Watchers.

DO’s ✅

Clear, sharp, and recognizable photos of litter
Try to limit your photo to one item per image, but if there’s a lot of litter in one spot, you may take a photo of multiple items at once. Just make sure each piece of litter is clearly visible—avoid stacked objects if possible.
Items should be centered in the frame; feel free to zoom in to make the item clearly visible.
Try to ensure even lighting.

DON'Ts ❌

No people, faces, names, license plates, etc. (comply with EU General Data Protection Regulations - GDPR)
No blurry or distant photos
No fingers, feet, hands, etc. in the frame
Avoid overexposure as well as shadows (including your own)

📍 Turn on location services for your camera

To create an accurate litter map, it’s important that we know where your photos were taken. So make sure your camera’s location settings are enabled.
Below, you’ll find a short step-by-step guide to check if this is the case on your phone.
It’s best to upload your photos directly from your phone to avoid losing the location data when transferring them to another device.

📱 iPhone (iOS):

Go to Settings → Privacy & Security → Location Services
Turn Location Services ON at the top
Scroll down to Camera → select While Using the App

🤖 Android:

Go to Settings → Location → turn Location ON
Go to Apps → Camera → Permissions → Location
Select Allow only while using the app

Still have questions about how to take photos or how to set up your phone? Be sure to check out the infographic below. It provides a clear and structured explanation of how to get started.

Infographic River Watchers

Download

Start here & join the river watchers!

Upload your trash photos to our system.

Add your dots to our map!

Help map pollution in Belgium. On the map, you can see where other River Watchers have already reported litter. Together, we’re creating a litter map that shows how much and what kind of waste is found in different places.

For every photo you upload, you earn one Trash Token. The yellow areas on the map are focus zones—these are regions where we don’t yet have many photos and would like to gain a clearer picture. Upload a photo from a focus zone? Then you earn double Trash Tokens per photo!

Are you feeling extra motivated?

Want to do more? We’re organizing an additional study where you collect data five times along the same route at different moments between June 26 and September 20, 2025. We’re looking for 100 motivated participants. You can sign up via this link.

Help out behind the scenes together with River Cleanup and VITO.

In addition to taking and uploading photos of litter, you can also help improve our artificial intelligence. Through the River Watchers project on Zooniverse, you can assist in recognizing and classifying the litter shown in photos. By answering a few simple questions, you help train the AI model to better identify waste.
This way, you’re not only making the problem visible—you’re also contributing to a smart solution. Your effort truly makes a difference! And who knows, you might even spot your own photos!
Head over to https://www.zooniverse.org/projects/avoverlo/river-watchers and start identifying waste!