The data contained in this database can be accessed through a series of web pages which form part of the EEA Data Service's public web site. Pre-defined applications have been designed to assist the user to extract and analyse the data in a format that is both helpful and meaningful. Reference Waterbase contains timely, reliable and policy-relevant data collected from EEA member countries through the Eurowaternet (EWN) process. EWN selects validated, mostly aggregated, monitoring data from national databases and adds information on the physical characteristics of the water bodies being monitored and on the pressures potentially affecting water quality. Although many countries make their highly aggregated data available over the Internet, the level and form of aggregation often varies from country to country making detailed quantitative comparisons difficult. The added value of Reference Waterbase is that data collected through the EWN process are from statistically stratified monitoring stations and groundwater bodies and are comparable at European level. These data are primarily used in the production of the EEA's indicator-based factsheets. Data disclaimer: The data in Reference Waterbase are sub-samples of national data assembled for the purpose of providing comparable indicators of pressures, state and impact of waters on a Europe-wide scale and the data sets are not intended for assessing compliance with any European Directive or any other legal instrument. Information on the national and sub-national scales should be sought from other sources.