This research aims to investigate the impact of river training structures (i.e. groins or spur dikes) on the flow characteristics of a stream. Twenty-eight run experiments were carried out in the Hydraulics Research Institute (HRI), the National water Research center (NWRC). Three main effective variables were tested (i.e. contraction ratio (L/B), groin orientation angle, and the discharge). It is to be noted that the tested contraction ratios were 0.1, 0.15 and 0.2. On the other hand, the testes orientation angles were 60°, 90° and 120° (i.e. attracting, straight, and repelling groins, respectively). The tested discharges were 10, 20, and 30 liter/s. Measurements were undertaken to determine the working length, scour, so as silting geometry and observations were documented. The measurements were analyzed and represented. Based on the experimental observations, the effect of the groins on the flow was described. Also, prediction attempts, to describe the interaction between the groin- fields and the main channel, are presented.
Based on the analyzed experimental results, it was clear that the straight groin of 0.2 contraction ratio provides the maximum working length while, the attraction groin of 0.1 contracting ratio provides the minimum working length. It was also determined that the morphological changes are directly proportional to groin length and discharge