Acta Scientiarum Polonorum

The article contains the analysis of the conditions of water flow through the trapezoidal stone permeable sill
with a sharp-crested weir on the upper slope. The aim of the analysis was to develop a nomogram and mathematical
relationships to determine the width of the sill covered by the overflow stream. In the implementation
of the task, our own model research and results provided in the literature were used. The tests covered a part
of the overflow stream at the length of which water inflows into the body of sill. The hydrodynamic similarity
principle according to the Froude criterion was used to transform the results into objects in nature. The
profile of the stream flowing over the tested sill is influenced by the diameter of the aggregate from which
the permeable body is made and the unit water flow rate. The result of the works carried out in the article is
a nomogram and regression curves for determining the length of water inflowing to the permeable sill. In the
analyses, the good fit of the equations into the introduced variables was obtained. The obtained results can be
used in the design of this type of field structures.