Prema Okvirnoj direktivi o vodama, postizanje ekoloških ciljeva mjeri se i ekološkim stanjem površinskih voda, a da bi se ono moglo odrediti potrebno je odrediti ekološki tip (ekotip) površinskih voda. Površinske vode prostorno se raspoređuju u tipove-cjeline, koje prema unaprijed određenim kriterijima imaju specifična ekološka obilježja. Republika Hrvatska je odabrala primjenu tipologije sustava B, prema projektu koji je 2005. godine izradio Prirodoslovno-matematički fakultet. U radu su dani preliminarni rezultati primjene tipologije na slivu rijeke Drave, a također su dane i napomene za daljnji rad. Opisanom tipologijom određeno je 10 ekoloških tipova vodotoka, koji predstavljaju 22,53 posto  ukupne dužine svih vodotoka na slivu rijeke Drave. Klasifikacija vodotoka prema površini sliva, prema nadmorskoj visini i prema litologiji te postotna zastupljenosti pojedinih ekoloških tipova dobivena je na osnovu ukupne dužine svih tipologijom obuhvaćenih vodotoka. Preliminarna tipologija površinskih voda izvršena je na osnovi ekspertne procjene, a njihovo daljnje preciznije i pouzdanije određivanje istih (do referentnih uvjeta) bit će moguće nakon uspostave i višegodišnjeg rada biološkog monitoringa..; According to the Water Framework Directive, the achievement of ecological goals is also measured by ecological status of surface waters. In order to determine this, it is necessary to determine the ecological type (ecotype) of surface waters. Surface waters are spatially distributed into types/bodies, which have specific ecological characteristics according to the predetermined criteria. The Republic of Croatia has chosen to apply the B system typology, according to the project which was developed by the Faculty of Science in 2005. The paper presents the preliminary results of the application of the typology to the Drava river basin, with notes for further work.  Through the described typology 10 ecological watercourse types were determined, which presents 22.53% of the total length of all watercourses in the Drava river basin. The watercourse classification according to river basin surface, altitude, lithology and percentage representation of individual ecotypes were obtained on the basis of the total length of all watercourses included in the typology. A preliminary typology of surface waters was carried out on the basis of expert assessment, and additional, more accurate and more reliable determination (up to reference conditions) will be possible after the establishment and years-long biological monitoring.