Various interventions need to be done in riverbeds for achieving certain goals (recreational, economic, flood prevention).
However, they should have a low impact on river environments. This paper analyses the effects of a rise in the upstream water
levels as an indicator of the impacts magnitude. We found that such an intervention can generate low impacts if it does no result
in arise of the water levels. The study was carried out considering two rivers in the North East of Romania: Siret and Bahlui. The
conditions in which various interventions can have low impacts were identified by analyzing two possible situations: a river
water intake and a discharge sill with flap gate.