FreshWater Watch (FWW)

A methodology for Citizen Scientists to use sensors to investigate the health of the world’s freshwater ecosystems.

Developer: Earthwatch Europe
Contact: Steven Loiselle (
Approximate cost: It is simple to join FreshWater Watch. The basic package includes kits for nutrient reagents and a turbidity tube as well as online training, support, quality control and data management. The base cost for a year is £400, including set-up and training, and to continue in future years an annual fee of £200 applies. Kits are purchased separately according to your needs (£40 per starter kit, £10 per refill). More advanced packages are also available upon request. Costs exclude VAT. For more information and to express your interest visit the FreshWater Watch website.


  • Resolution: Spatial depending on GPS of participant cell phone; Temporal depending on citizen scientist; 
    No greater than daily, no smaller than annually
  • Dimensions: 50 cm x 3 cm
  • Power requirement: None
  • Method to transmit data: Dedicated free App
  • Deployment method: Manual

Supporting materials

Video: An Introduction to FreshWater Watch - YouTube


The Freshwater Watch (FWW) programme uses various sensors to monitor the quality of small freshwater environments, coastal conditions of large freshwater environments and spatially distributed conditions of catchments at both local and international scales.

FWW sensors are used by trained citizen scientists to measure nitrates, phosphates, water level, water colour and turbidity, and record the general conditions of the water body related to potential pollution sources, hydrological conditions and land use.

Through the MONOCLE project the interoperability of the FreshWater Watch methodology has been improved and FWW data are now available on an open Geoserver.

What does it measure?

  • Nutrient pollution (nitrate and phosphate concentrations)
  • Turbidity
  • Water colour (categorical)
  • Ecological conditions (presence of algal blooms, in stream vegetation)
  • Hydrological conditions (river velocity, lake height)
  • Site characteristics (bank vegetation, land use, water uses, litter presence/absence, pollution evidence)

How does it work?

Measurements and observations are made by citizen scientist then time stamped, location stamped and uploaded onto data platform where they are checked for anomalies.

Image gallery

Technical drawing

Deployment information


Standardised data access

We provide several interoperable data interfaces, as detailed below:

Metadata available in CSV (raw) format
WMS WFS (validated records)

Documentation and publications

Supporting materials

Video: An Introduction to FreshWater Watch - YouTube
Download the operational protocols for MONOCLE sensors and platforms
This document provides a set of protocols for the deployment of MONOCLE systems to ensure best practices to collect reliable data.
System user and developer handbook

This handbook provides an overview of the data requirements and interfaces that were adopted in the sensors and observation platforms of MONOCLE.

Examples of sensor use

Freshwater Watch map of results
Thames Blitz : 2014 – 2019
Dublin Blitz: 2019 
Paris Blitz 2019
Luxembourgh Blitz 2019 
Vattenfokus Blitz 2018 

Publications and articles

Other sensors and platforms

Hyperspectral Radiometer for Global & Diffuse Irradiance (HSP1)
A novel sensor to accurately measure the spectrum of sunlight near the water’s surface

Solar tracking radiometry platform (So-Rad)
Control and automate underway radiometric measurements for satellite validation from ships and buoys

Take quick and easy ocean colour measurements using this low-cost add-on for your smartphone.

MapEO Water
Using state-of-the art drone technology to monitor water quality. The MapEO Water service converts drone data into geo-referenced images providing information on the physical properties of water bodies.

Water Insight SPectrometer Station (WISPstation)
Measure water reflectance and key water quality parameters fully autonomously, emission-free, without any chemicals, at a high frequency and get results available near-real-time

Measure water transparency with a low-cost sensor that you can build! Advanced KdUINO sensors also detect optical and temperature stratification in the water column.

Mini-secchi disk
Measure water transparency, colour and pH with the mini-Secchi disk: a handheld device that is easily deployed from shore or boat.