Between the 21st and 23rd March 2016 an international Citizen Science Workshop was held at the Department of Vegetation Ecology. The workshop was a part of the activities of the COST Action NETLAKE which is a network of institutions and individuals focused on lake and water reservoir monitoring across Europe and some other parts of the world. NETLAKE is the overarching COST action of the national COST project FISHPOND2014 which is running on the Department of Vegetation Ecology since 2014 under the leadership of K. Šumberová who is at the same time the member of the NETLAKE Management Committee for the Czech Republic and was the main organizer of this workshop. Altogether 22 participants from 8 countries (Czech Republic, Ireland, Italy, Denmark, the Netherlands, Serbia, Sweden and Turkey) attended the workshop. The program involved oral presentations on the Citizen Science projects in individual countries (e.g. the projects publicising water protection among general public including pupils or community of divers or fishermen) as well as practical examples of what can be observed in standing waters using easy-to-make instruments. Together with the other participants we learned for instance, how to make a Secchi disk – an instrument for water transparency measurement – from an old CD, how to estimate water quality according to water colour, using a simple colour scale, or how to monitor decomposition rate in a standing water body using tea bags. From the team of FISHPOND2014 project altogether three people participated and at the same time co-organized the workshop and other colleagues from the Department helped with the workshop organisation as well. The workshop was evaluated by all the participants and also the leaders of the NETLAKE COST Action as highly successful and useful, and thus it helped to strengthen international co-operation in water protection and its popularisation.