Improvement and reuse of water returned from agricultural irrigation in the discharge channel with gabion technique

A study conducted in 2022 in the Harran Plain of Şanlıurfa utilized the phytoremediation technique for the improvement and reutilization of agricultural wastewater. The study area focused on the Çepkenli Village HT11-2 drainage canal and the Çolpan Regulator, which are located within the service area of the Southeastern Anatolia Project (GAP) Irrigation Association. The study took place between May and October. In conventional irrigation practices, agricultural wastewater is discharged into drainage canals through surface runoff. Subsequently, tertiary, secondary, and main drainage canals gradually merge and form a conveyance channel, which leads to the discharge into the receiving environment. The recovery of water losses, particularly resulting from uncontrolled irrigation, is achieved through regulator structures designed and constructed by the State Hydraulic Works (DSİ) on drainage canals. In this study, a monitoring and evaluation period of 149 days was conducted by the General Directorate of Water Management (SYGM) to assess the phytoremediation system implemented. During this period, a total of 9,913,476 m3 of reclaimed water from the phytoremediation system was discharged into the HYA canal through the Çolpan Regulator, with the aim of reusing the water in new areas. Based on the measurements taken, it was observed that the total suspended solids (TSS) and Total Dissolved Solids (TDS) values were high, while the lowest values were recorded during the final irrigation cycles. In the study area, it was determined that sediment transport occurred due to rolling, sliding, and splashing movements, resulting in the displacement of a total of 6,274 tons of material from an area of 717 hectares.