Deposition of detrital material of turbiditic origin can modify the cycling of phosphorus in freshwater sediments. It may preserve mobile P from being released to the water column and maintain P at the ancient sediment-water interface. A conceptual model is proposed to explain the trapping of P in sediments. For sediments having a large inventory of mobilizable P, immobilization in sediments by turbidites or even thin detrital layers may positively influence the water quality of the hypolimnion. Examples of this phenomenon are presented for four sites in two Swiss lakes