Laboratory Tests of New Groundwater Table Level Regulators in Subsurface Drainage Systems

Abstract

The changes in hydrological conditions observed nowadays require economical use of water. This applies to water management both on a national scale and river basins and catchments, as well as on the scale of drainage systems and individual drainage networks. Outflow regulation is carried out by extending the outflow time of surface water collected during rainfall in various forms of retention in the catchment area. One of the devices for regulating the outflow of groundwater is a drainage network, traditionally used as a drainage system. The water level regulators presented in this article enable the damming of water in the drainage network, in pipelines and in the adjacent ground. The conducted tests were aimed at determining the hydraulic characteristics and operating conditions of two innovative solutions of water level regulators in drainage systems. These regulators are characterised by the possibility of smooth regulation by the use of rotary or propeller systems for smoothly setting the damming level. Both tested regulators are characterised by the presence of an effective flow, the value of which was set at the level of Qe = 0.17 l·s−1 to Qe = 0.25 l·s−1 for the funnel regulator and Qe = 0.009 l·s−1 to Qe = 0.015 l·s−1 for a hole regulator. Laboratory tests of the prototypes showed that the funnel regulator allows one to maintain the damming level in a flow rate range of up to 5.5 l·s−1, with possible damming up to 3 cm, regardless of the height of the shaft. The hole regulator is characterised by a flow control range of up to Q = 0.65 l·s−1, greater variability of the damming levels and the need to change the position of the working openings, depending on the flow rate.