top of page

Smart Rainbarrel - ZOHO Rainletters

The ZOHO Rain Letters: Smart rainwater buffer and area icon in one

Due to climate change extreme weather events are increasing. Longer periods of drought alternate with large amounts of rain in a short time. The sewer cannot always handle so much water, causing problems. The ZOHO Rain Letters developed and designed by Studio Bas Sala contribute to the solution for these inconveniences in a smart and sustainable way.


The rainwater from the roof of the Hofbogen is not led into the sewer but into the ZOHO letters. Here it is buffered and when necessary released into the surrounding garden. The built-in smart system looks at the weather forecast via internet. As soon as a heavy rain shower is expected, the tanks release water automatically and create buffer capacity for the coming rain. This sustainable system works on solar energy.


The ZOHO Rain Letters are not only a rainwater buffer but also a signboard for the area. The name “ZOHO” refers to the name of the area “Zomerhofkwartier”. They were developed and built in Rotterdam. For the production Studio Bas Sala collaborated with Wijkcoöperatie Noord. This organization works with volunteers from Rotterdam Noord.


more info: 


Photo: Stijn Brakkee

Working principle​:


Project data:

Design: Studio Bas Sala 

Production: Studio Bas Sala in collaboration with Wijkcoop Rotterdam Noord

Clients: Municipality of Rotterdam and Hoogheemraadschap van Schieland and Krimpenerwaard.

Capacity water buffer 3000 liters

Project implementation 2015-2018

This project is supported by:

Wijkcooporatie Rotterdam Noord

Hoogheemraadschap Schieland en de Krimpenerwaard

Gemeente Rotterdam

Life EU

bottom of page