Rain and sewer overflow

When investigating swimming water quality, we learned from the experts that sewer overflow after heavy rainfall is one of the primary causes of ill-making bacteria in the water. Since these bacteria themselves are hard to measure with simple sensors, we decided to work on sensors that indicate sewer overflow. In many cases a couple of days after such an overflow the water is known to be not safe, but the bacteria mostly disappear a few days later. To get an idea on the relationship between rain and sewer overflow, we also installed a rain meter on top of the Smart Roof on the Marineterrein. With that we hope to get insight in the amount of rain that causes sewer overflow. We are aware that there are other factors that get bacteria or algae in the water, but this will help to get the whole measurement, data collection and data analysis infrastructure in place. We hope that together with experts in this field we will be able to improve the set-up and get a quite reliable alerting system.
Technical: Raindata is currently collected with a Davis Rain Collector and sent over WiFi to the Sensemakers backend at SURF Sara. There it is stored in an Influx database for further analysis. The data is available here.