The Copernicus Assisted Lake Water Quality Emergency Monitoring Service platform (WQeMS) is an outcome of the H2020 WQeMS project. It leverages on experimentation and service development relatively to lakes and open surface water reservoirs located in Finland, Germany, Greece, Italy, and Spain. Four service lines have been realized concerning 'Water Quality Features Changes', 'Bloom Events Detection', 'Land-Water Transition Zone Change Detection', and 'Extreme Events Detection'. Furthermore, a crowdsourcing mobile app allows for collecting timely in-situ information, crucial during crisis' management. WQeMS flexibility and interoperability are advantageous for interfacing with Copernicus Services and the Group of Earth Observation System of Systems (GEOSS) platform. These features support proposing WQeMS as an evolution element of the Copernicus Emergency Management Service (CEMS). In addition, WQeMS modularity makes it possible to test its services with new satellite data and improve the processing chains. Finally, WQeMS platform can serve both, expert users wishing to test alternative methods, and users non familiar with Earth Observation data. Access to some water utilities and water domain engaged parties will be considered towards the end of the project (June 2023) in view of service commercialization. WQeMS sustainability should be attained by providing commercial services, still leaving room for research studies.