The target of the open source hydrodata.cz web application and web services is to bridge the gap between modelers and field hydrologists by providing free, publicly accessible precipitation, snow, temperature, and discharge data series from multiple organizations in the Czech Republic using the standardized the CUAHSI WaterML data format and search services. Data providers contributing to this effort include the CUAHSI, NOAA, Charles University experimental watershed network, Czech watershed authorities, and networks of volunteer observers. Time period covered includes the floods of 2006, 2009, 2010 and 2011 as well as the 2007 drought. Adopting the WaterML standard also allows the use of other free third party client side web based and desktop data discovery software tools – which has the added benefit of making the Czech Republic hydrological data more readily accessible to the international community.