Evaluasi Elevasi Saluran Drainase Untuk Meminimalisir Terjadinya Perlambatan Aliran (Studi Kasus Drainase Jl. Wonosari Barat - Jl. Sd 04 Damon)

The drainage system along the stretch from Jalan Wonosari Barat to Jalan SD 04 Damon in Bengkalis Regency suffers from flow deceleration and water pooling issues linked to the channel bed elevation. This study aims to assess the existing drainage channel elevations, determine the impact of elevation irregularities on flow velocity, and provide technical recommendations for channel improvements. The research utilized primary data obtained from field measurements along a 1.74 km stretch of the channel. Analysis involved calculating elevation differences (ΔH), channel bed slopes, and flow velocities using Manning's Equation. The results indicate non-uniform channel bed elevations, evidenced by varying ΔH and slope values across different segments. This condition causes flow velocities to fluctuate along the channel. Segments identified as prone to flow deceleration include P20P21 (0.733 m/s), P21–P22 (0.689 m/s), P27–P28 (0.257 m/s), P53–P54 (0.550 m/s), and P97–P98 (0.946 m/s). Segment P27–P28 exhibits the lowest flow velocity (0.257 m/s) and a slope of approximately -0.0003, marking it as a priority area for attention. Improvement recommendations include evaluating and realigning channel bed elevations in segments with low slopes or irregular elevation changes, normalizing the channel bed in areas affected by sedimentation, periodically clearing debris and wild vegetation, and conducting routine maintenance of the drainage system.

Keywords: drainage, channel elevation, channel slope, flow velocity, Manning's Equation.