Buoy measures water quality

28 June 2017

If you see a big yellow Lego head in the harbour of Marineterrein Amsterdam, don’t panic. It’s a buoy that measures the water quality.

Exercise and movement are part of a healthy city and the Marineterrein. That’s why the first exploration into possibilities for swimming in the inner harbour was launched in 2016. There’s still a long process ahead before the harbour can become an official swimming spot. A lot of data needs to be collected in addition to Waternet’s monthly measurements. That’s why Sensemakers, at Bureau Marineterrein Amsterdam’s request, has designed a measuring buoy. The Lego head is the first working prototype created by Makerversity Sensemakers.

Who is Sensemakers?

Sensemakers is a group of technicians who meet once a month at the Makerversity on the Marineterrein to share knowledge about the Internet of Things. Because each person has their own specialization, the entire design process – from idea to product – is quite the educational experience. Where one has broad knowledge of electronics, the other is skilled in writing software, and yet another in design.

Step 1: measuring temperature and flow

The first version of the buoy starts with measuring the water temperature and the flow. The values are reported back using LoRa, a recently developed wireless network which has set Amsterdam well-ahead of the pack. Through the internet (or via a mobile web app), everyone can see if the water is warm enough to swim in comfortably. The buoy is powered by solar energy.

Step 2: measuring pH levels and oxygen content

In the coming months, the buoy will be fitted with extra sensors. This gives us more insight into water feature levels such as pH levels and the amount of oxygen in the water. The measurements will be analysed and compared with official measurements in consultation with Waternet specialists and water authorities.

Additional objective: data sharing

An important additional objective of the project is more knowledge sharing around water quality. In the Netherlands, we have good water companies and water authorities, but in many parts of the world, it’s not as well regulated. Both schools and citizen science initiatives are looking into how we can gather data that gives us a better view of what’s happening in our water. Keeping costs down for the parts we use is also an important part of the project. Otherwise, it will be too expensive to implement elsewhere in the world.