CALCULATION OF RAINWATER SEWAGE SYSTEMS

Rain intensity is highly variable, making it difficult to accurate calculation of runoff and the flow rate that results in periodic flooding of streets and squares disturbing the traffic and making material damages. The developed rainwater system calculation method is capable of determining the rainfall maximum flow rates of different surfaces with different surface probability (1-200%) in the whole territory of Latvia. The maximum stormwater flow rates are determined according to the expression based on A.Ziverts' formula that is refreshed by R.Ziemelnieks in the promotion work. The gully between the placing distance ridged edge of the road is determined by the expression which was calculated at the end in this publication. LBN 223- 99 was used for rainwater calculation time for gully flow and the formula for calculating the minimum slope of the rainwater collector. The paper gives the k-values of Latvian towns, depending on the desirable flow of rainwater. The method developed enables the calculation of the maximum rate flow of rainwater in urban areas with different probability and the distance between two adjacent intermediate gullies.