Abstract
In order to provide sustainable management of rivers it is necessary to seek equivalents in nature. For hydromorphological status assessment and for proposals of measures aimed to achieve good status of rivers in the context of Water framework directive (2000/60/EC) is required to identify reference conditions as the comparison object to present conditions.
Reference conditions should reflect natural variability of longitudinal and cross-section pro-files and channel course in accordance to given river type, natural river bed and bank ma-terial, natural movement of sediments, organisms and stream flow in the channel and river floodplain. Presented REFCON methodology is based on principal of establishing the reference sites from field survey and the identification of hydromorpholgical characteristics of rivers im-portant for the establishment of type specific reference hydromorphological conditions.
The establishment of reference sites is conditioned by 7criteria: unaffected hydrological regime (no crosswise obstacles above 0.5 m, no dams, reservoirs, or pond systems consisting of two or more ponds above the reference site, no significant water extraction or diversion), natural banks, bed, and channel course, good conditions of riparian zone, and no significant sources of of pollution affecting reference site. After considering remote data and field sur-vey results it is possible to identify the locality as reference, if fulfilling required criteria, or anthropogenically modified in case of not fulfilling the criteria or individually assess whether to identify the locality as a best available.
The database of reference sites should then serve not only the purpose of hydromorpho-logical status assessment, but also as a template for revitalisation measures proposals or as a database of river segments, which would be appropriate to protect from human activity influence.