The Hague waters its planters with data: 1.2 million litres saved

What is measured and how it is decided

Some 160 sensors track the condition of the city's 1,800 planters. There is no need for one sensor per planter: they are grouped by plant type, exposure and substrate, and one representative sensor covers its group. The platform calculates the amount of water for each and generates the day's route.

The architecture is that of a classic IoT ecosystem: sensor → LoRaWAN → platform → analysis → application → action in the field.

The results

According to the Dutch trade press, the city saved some 1.2 million litres of water in four months. A watering round that used to take eight working days now takes six, and some of the maintenance companies' routes were shortened by 25 %, with less fuel and fewer hours.

The calculation: what those figures mean per planter

1,200,000 L ÷ 1,800 planters ≈ 667 L per planter in four months, about 5.5 L per planter per day (667 ÷ 120). That is the water that used to be given in excess, or at the wrong time.

And the round going from 8 to 6 days is a reduction of (8 − 6) ÷ 8 = 25 %, consistent with the published route shortening. Fewer route days mean fewer lorries on the street: the water saving comes with savings in diesel and staff hours.