RiverMonitor
What:
Monitor conditions of a river - speed, depth, ...
Participants:
{{#arraymap:User:Anton|,|x|Has participant::x}}

My parents have a small stream flowing past their house. I want to monitor it, initially the depth and speed, but in future more

The plan is to build a set of sensors, possibly things like a 3d-printed impellor for flow speed, linked to some cheap microchip AT-??? with an RF transmitter. Initially I am working on an arduino powered setup

Mass Water Flowmeter

Possible idea for metering flow: Cars use a Mas Air Flowmeter that consists of an exposed heater element and a passive temperature sensor. With a regulated voltage supply the resistance of the heater element is related to the flow of air past it (or water in this case). The advantage is that there are no moving parts, the disadvantage is it might become blocked, or the heater become damaged (it doesn't need to be a wire). You'd also need to measure the cross section of the flowing water, which probably flows less at the bed. Can you install a dam, would make a lovely pond?