Аннотация:Model calculations for the Ivankovo Reservoir show that phosphate flows in a reservoir in theperiod of its filling with flood waters can be controlled. Changes in the flood passage regime with a loop-likerelationship between mineral phosphorus concentrations and water flow rates in the river, lead to a decreasein the total phosphate reserve in the reservoir during the pre-vegetation period. Calculations show that in ayear with medium water content this decrease in the Ivankovo Reservoir can reach 25%.