Design of a Check Dam for Sediment Control in Pacet District, Mojokerto Regency.

Pacet District, Mojokerto Regency, is a highland area that is prone to natural disasters such as flash floods and debris flows due to high rainfall and steep topography. To overcome the problem of sedimentation and potential disasters, a technical study is needed in the form of a check dam control plan. This study aims to analyze the planned flood discharge, the effect of flooding on sediment transport, and plan the dimensions and stability of the check dam structure in the Kromong River. The methodology used includes hydrological analysis using rainfall data with the Gumbel method to determine the planned discharge obtained 817.29 mm with a coefficient of 0.7, in the Nakayasu synthetic unit hydrograph calculation method produced 1649.67 m3/sec in a 50-year return period, the sedimentation calculation method uses the Takahashi method to obtain 1680.034 m3/sec and the planning of the check dam dimensions. Structural stability against overturning forces, sliding forces and earthquakes. The calculation results show that the planned check dam is able to withstand peak flood discharge with a 50-year return period and has stable dimensions. This research contributes to disaster mitigation and sediment control efforts in areas prone to landslides and floods and can be used as a reference for the construction of check dams in these areas.