Summary:

In the study there was presented simulation of the volume counting of the water coming from surface flow which appears on highland forest roads. The basis were actual measures of surface flow from roads done in the Silesian Beskid in 2003-2004 period, and assumption of conditions homogeneity in 100 ha area for which the calculation was made. For different index of road net density (from 10 to 30 m∙ha-1), different precipitations (1,1; 2,1; 5,2; 9,8 mm) and established 3-hour lasting rainfall there was shown the simulated water amount and its pro-portion to precipitation (P) on total area. Results, among others, are as follow: for road net density 10 m∙ha-1 and rainfall 1,1 mm - 376 liters (0,03% P), for road net density 30 m∙ha-1 and rainfall 9,8 mm - 58 077 liters (0,6% P). There was also calculated surface flow volume on based on the data measured in snow melt period (3 hours long period) and the results are as follow: for road net density 10 m∙ha-1 - 75 588 liters, and for road net density 30 m∙ha-1 - 226 765 liters of water. In part of discussion we compared these results with standard water con-sumption by statistic person. In this comparison the results are inter alia: run-off volume for rainfall 9,8 mm and road net density 30 m∙ha-1 581 times greater than daily quota water use for person. In the comparison of volume of the run-off came from snow melting from road net with density index 30 m∙ha-1 and daily require-ment per person results 2 268 times difference.